A via 2 Manual

8/4/2019 A via 2 Manual

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Introduction to Advanced Patterns

The Avia II patterns included in this section of the disc include not only the basic setup patterns but

also a greatly expanded set of auxiliary patterns. Many of them can be used to refine a screen setupperformed using the basic patterns. Others can be used, without test instruments, to measure or assess

how well your system is doing in a number of areas of critical video performance, such as resolution,gamma, and progressive-scan conversion. Still other patterns can be used by a professional installer toperform rigorous adjustments of screen performance.

As you may have noticed from the menus, the Advanced patterns are in pretty much alphabetical order,both in their section names and in the pattern names within each section. This manual covers the

patterns in section-name order, but within each group, discusses the patterns in the order most

appropriate for the type of test pattern, alphabetical or not. The patterns in the Miscellaneous section

are discussed in alphabetical order.

Throughout the descriptions, we have tried to remain as technically accurate as possible. Thats whyyou will find here such terms as luma, for the signal carrying the video brightness information,instead of the more common, and technically incorrect, luminance, which has its own, specific usage.

Most of these technical terms are defined in the accompanying glossary file.

Avia II Manual Ver. 1.0 1


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CHECKER STEPS

Checker Steps Deep 5 x 5 Gray: On a large-screen projection system you may detect

different contrast performance at the edges of

the screen using a Checker Step pattern.

Plain checkerboards are used in tests of a screens contrast ratio, but such measurements require

specialized test equipment. For the home user, a checkerboard can be used to confirm correct geometry

(see also the Circle Hatch and Hatch sections) with all the angles being perfect right angles and all the

checkerboard boxes being exactly the same size. This is usually the case for flat panel displays but bothfront and rear projection sets might have visible geometry problems because of their complex optical

systems.

Some technicians prefer a checkerboard pattern, as opposed to a hatch screen, for setting static anddynamic convergence in projection systems. Geometry is correct when all boxes are of equal size,

identical shape and otherwise undistorted throughout the display. Convergence errors appear as color

edges around the white boxes. The sharp vertical edges of the boxes may also be used to set peakingcontrols sometimes found in CRT-based projection systems. When peaking is correct, the vertical edges

will appear sharp and will not have the false outlining or fringing characteristic of ringing. Edge-

enhancement controls should also produce no ringing.

Projection sets might also display variations in contrast and brightness performance in different parts ofthe image, particularly near its edges. This is where the inner steps in the Avia II checkerboards come

in. The patterns in Checker Steps enable the verification of grayscale tracking as well as of the

preservation of highlight and shadow detail across the entire screen. The patterns are provided in

multiple rectangle counts, with either shallow or deep cross steps, and in the three primary colors aswell as gray. If brightness and contrast have been set correctly, all the steps should be visible since the

darkest near-black step is still above pure black while the brightest near-white step is below peak white.

Of course with the all-gray patterns there should be no variations in color of either the white in thecheckerboard on in the grays of the steps. Such variations would indicate either grayscale mistracking

or optical problems in a projection system.



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CIRCLE HATCHES

Circle Hatch 100: You can quickly gauge aprojection systems geometry and alignment

with any of the Circle Hatch patterns.

Circles: Perfect circles are a simple way to verify picture geometry, especially if you take a ruler or

tape measure to a Circle Hatch pattern and confirm that every circles height is precisely equal to its

width. This is often not the case, even with fixed-pixel displays like LCD and plasma that otherwisepass alignment and geometry tests that are difficult for projection displays. Thats because many

widescreen displays are not precisely 16:9 in their pixel count, and to completely fill such a display

with a 16:9 image (such as the patterns in Avia II) the picture is slightly stretched, usually in thevertical direction. The circles heights will then be very slightly greater than their widths.

Hatches: These are used to detect geometric distortions that create any areas of the screen where the

horizontal and vertical lines do not meet at perfect right angles or deviate from perfect parallelism.

Typical deviations from ideal performance in projection sets include barrel distortion (bulging outwardfrom the middle), pincushion distortion (a bulging inward towards the middle) and keystoning (a

narrowing of the image at the top or bottom). If a projector has separate optical elements for red, green

and blue primary colors their alignment can be checked with hatches as well. In particular, errors in

convergence (the perfect alignment of red, green and blue images on top of each other) can be exposedby using the hatch patterns.

Selectable Grid Intensity and Colors: Crosshatch intensities of 40, 60, 80 and 100 IRE (indicated in

the pattern name) as well as tinted and multicolor hatches are provided. Tinted grids make red, green,and blue approximately the same visual intensity so convergence adjustments in a projection system

can be performed without turning off or capping color guns. Multi-color grids vary in color and reveal

small convergence errors as motion of the grid as the colors change.

Adjustable Grid Spacing: Variable hatches (the ones containing Zoom in the menu) place gridintersections exactly where they are needed. Use DVD player Play, Pause, and Reverse controls to

select the grid spacing desired. The Zoom Hatches can also be used to assess how geometric

distortions, if any, change across the image.



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COLOR BARS

Super Blue Bars: This version of the classiccolor-bars pattern has been arranged for

easiest saturation and hue adjustment using

the supplied blue filter. The surroundingwindowboxing keeps important elements on

screen (and measures overscan). The top gray-

reference bar helps in evaluating color

decoding. This image has been altered to showthe faint brightness and contrast calibration

bars in the lower third.

Green Bars: You also can set hue and

saturation using the green filter and this

pattern, which also has brightness andcontrast calibration bars in the bottom third.

Use the red filter with the similarRed Barspattern.

Color Checkerboard: As a cross check that

your blue-bars (and, possibly, red- and green-

bars) settings are correct, this pattern allowsyou to adjust all settings simultaneously.

Settings are correct when the pattern becomes

a nearly uniform color when viewed with eachone of the color filters. The upper half of the

pattern is affected by the settings of the

saturation (color) control, the lower half by

the hue (tint) control. See also theMiscellaneous Tricolorpattern.

One of the classic test patterns, whose origin dates to the early days of color television, a color barspattern from a DVD player can be used to accurately set the hue (tint) and saturation (color) controls of

a display. A wide variety of familiar, and new, color bar patterns are available on Avia II. Three of thefour most useful patterns for home viewers are shown above (only Red Bars isnt shown). All four are

intended to be viewed through one of the supplied color filters.

The Blue Bars, Super Blue Bars, Red Bars and Green Bars patterns are constructed in a similar fashion.

Ignoring for the moment the bottom third of the patterns, which contain signals used to set contrast andbrightness (see the Levels section), the red-containing parts of these color-bar patterns (gray, yellow,

magenta, red) all have the same amount of red, the blue-containing parts (gray, cyan magenta, blue)



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have the same amount of blue, and the green-containing parts (gray, yellow, cyan, green) have the sameamount of green. (The gray here is a light 75% gray, cyan is the turquoise color, and magenta

the purple).

You calibrate a monitor using a blue-bars pattern by viewing only the blue component of the blue-

containing bars and patches, either by turning off the red and green signals feeding the display (as thepros do with studio CRT monitors) or by viewing the Blue Bars or Super Blue Bars patterns through

the blue filter. Front projector users may alternatively cap the red and green color outputs of theirprojectors, if there are separate color outputs. Blue is traditionally used because it was the color thatunderwent the most processing through an NTSC video chain. Ideally, the other colors should also

decode correctly once a display is calibrated to decode blue properly. An additional benefit of blue-only

calibration is that the user need not have perfect color vision to do an accurate adjustment.

Look at the pattern through the blue filter and note the relative brightness of the blue-containing areas,(which, again, are the gray, cyan, magenta and blue patches). Set the saturation (color) control to make

the gray areas match the blue areas in apparent brightness, and set the hue (tint) control to make the

magenta areas match the cyan patches. The flashing central patches help you zero in on the correctsetting by making brightness differences more obvious. When controls are accurately set, the apparent

flashing of the patches when viewed through a filter is minimized.

You will probably have to repeat the adjustments since making a saturation tweak will probably throw

off the match among the hue colors. Adjust them alternately to make both as correct as possiblerealizing that a compromise setting might be the best you can do.

Consumer displays often complicate color calibration by not following established standards. This

blue-only calibration procedure may produce exaggerated, cartoonish colors in some consumer sets. If

your display does not have a standard color decoder, you may have to tweak the blue-bars saturationsetting to reach a usable compromise setting. The same overall procedure, using the appropriate filter,

applies to the use of the Red- and Green-Bars patterns. You can check your results for all three colors

with a single pattern by using the Color Checkerboard (shown above).

Keep in mind that in many sets it will be impossible to get all three colors to come out perfectly. Thered-only calibration procedure in particular may produce dull, washed out colors if used alone. If your

display does not have an accurate color decoder, you may have to tolerate excess red saturation to reach

a usable compromise setting. In any case, try at least to obtain compromise settings that get the blueandred patterns to come out as good as possible.

Super Blue Bars and Bars Gray Bottom: Both of these patterns feature a large horizontal bar of 75%

gray. You can check color decoder accuracy with these patterns. Each colored bar has the same amount

of red, green and blue as in the gray bar. If color decoding is accurate, viewing these patterns throughthe color filters will show each colored bar matching the brightness of the gray bar. If any primary

color is over-emphasized by the displays color decoder, it appears brighter than the gray bar. If a color

is under-emphasized by a color decoder, its color band appears dimmer than the gray bar. Accurate

color decoding is vital for achieving accurate image rendition. Otherwise, colors will never bedisplayed correctly even if both saturation and hue are adjusted correctly for blue. A common

symptom of color decoder inaccuracy is over-saturated reds when blue saturation is correctly adjusted.

This produces reddish skin tones but decreasing saturation in an attempt to fix such skin tones willdesaturate all other colors. This is why we recommend obtaining settings that simultaneously optimize

both the red and blue patterns. For patterns specifically designed for checking color decoding, see the

Color Decoder patterns described further on in this section.

Split Bars 75, Full 75 Bars Patterns: These patterns contain the bars at the standard 75% saturationlevel.



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Full 100 Bars Pattern: The 75% bars patterns have traditionally been used for calibrating displays

because their colors come up to the broadcastable saturation limit set by FCC interchannel-interference

guidelines for TV stations. But the NTSC system and DVD-encoded video can both conveyunbroadcastable 100%-saturation signals. This pattern contains 100%-saturation color bars to help

evaluate how well a display handles full saturation signals. See also the Tricolor pattern in the

Miscellaneous section, whose top quarter is also at 100% saturation.Special color bar features: Many of the color-bar patterns have additional features for setting/testingwhite level (contrast), black level (brightness) in addition to the functions of conventional color bars.

Super Blue Bars even includes overscan markers with each graduation in the border indicating 1%

overscan (see also the Miscellaneous Overscan pattern). The special features include:

White-level bars: The standard Avia white-level bars (2 IRE below, 1 IRE below, and 1 IRE above100% white) are enclosed within the lower left 100%-white patch. They slide around to enhance their

visibility. See the Levels section on how to use them.

Black-level Bars: The sliding bars at 4 IRE below, 1 IRE above, and 2 IRE above full-black in the

lower right to indicate proper black level. They are very faint compared to the rest of the pattern even

when black-level is adjusted correctly. See the Levels section for how to use them and for patterns thatare easier to use because they arent as blindingly bright as color bars.

4.0 MHz T2 Edge Transitions: Horizontal edge transitions of the lower 100% white patch are

bandwidth-limited in a specific way (thats the T2). Suspect a too-high sharpness setting if you seeringing (a fringing effect) at the left or right edges of the white patch.

Y/C Timing Testing: Color-to-color transitions are sharp and aligned at MPEG color sampling

boundaries to permit evaluation of Y/C delay errors. See also the Pix YC Delay pattern in the

Miscellaneous section.

Color Decoder Coarse: Available with 10%(coarse) or 5% (fine) gradations between

color intensities, the patterns help quantify

color-decoding errors such as red push.

The two Color Decoder patterns measure how accurately each primary color is decoded. Not all

displays have accurate color decoders and it is common to have an overemphasis of red. On suchdisplays, accurately setting saturation and hue while viewing only a blue-bars pattern will not result in

accurate settings for red and green. This pattern contains a 75% gray background and patches of eachprimary color ranging in saturation from +25% to 25% (compared to the ideal, 0%, value) one of

which should match the gray background when viewed through each color filter. In Color Decoder

Coarse, the steps between color patches are every 5%, in Color Decoder Fine they are in 2.5%increments.

If a display has accurate color performance, the central red, green and blue 0% patches should all

match the gray background in apparent brightness when viewed through the appropriate color filter. If



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a display has non-standard decoding, patches other than the 0% ones will match the gray background.

To use either Color Decoder pattern, first calibrate your display using the blue-only technique

discussed above. Then view this pattern and verify that the 0% blue patch matches its gray background.

Next, using the correct filter, find the color patches for red and green that best match the gray

background. The labeled percentage next to each patch indicates how much that color is overemphasized. If the +15% red patch best matches the background then the display is over emphasizing

red by 15%. A negative number indicates a color is under emphasized. Since it is usually not possibleto recalibrate a non-standard color decoder, the solution is to choose the compromise saturation settingthat is least objectionable. Most viewers find oversaturation more distressing than mild

undersaturation. Oversaturation of green is usually not too objectionable, but red oversaturation is very

noticeable, especially on flesh tones. With inaccurate color decoding there will probably be no idealcompromise setting, but decreasing saturation until red is no more than 15% to 20% overemphasized is

a reasonable goal. The hue (tint) setting should not be changed after making this compensation even

though color bars may appear to be incorrect after making such a compromise saturation setting.



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COLOR FIELDS

Magenta Color Field: Check for color noise

with this full-field pattern, which should reveal

any noise problems.

Use these uniform field patterns to check for display uniformity and chroma noise. Displays may

produce variations in brightness (luminance) in different areas of the image. Compare the central andperipheral screen areas. A perfect display is uniform in color and luminance throughout. Any color

shifts or luminance variations are superimposed on viewing material, detracting from overall imageaccuracy. Chroma noise appears as small irregularities in the color of these patterns and is most easily

visible with a Magenta field. Properly operating modern equipment should not show any visible noise

on any color field. Low noise is a characteristic of computer generated video such as these test patterns.



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GAMMA BASIC

Important note: These tests are intended only as a means of estimating your displays gamma; they are

notintended for gamma adjustment, except perhaps to confirm that adjustments have been made

properly. Altering your displays gamma settings can severely disrupt the image if done incorrectly.

Precision gamma adjustments can be complex and require light-measurement instruments as well as the

Gray Field and Gray Window patterns. Gamma tweaking is best performed by a professional installer.

Gamma Coarse Checkered: The gamma

patterns are used to estimate display gamma,

which should range between 2.2 and 2.5.

Simply making red, green, and blue primaries track together at a white of 6500 K (grayscale

tracking) was once sufficient to establish a good foundation for imaging. That was in the days of the

CRT. Todays digital displays add another aspect to be considered gamma response. Simply put,gamma is a number describing how the light output of a display changes in relation to the input.

Video signals are encoded under the assumption that the display is non-linear. That is, the display is

supposed to respond to a linearrange of input voltages (or numerical data for digital displays) with anexponentiallight output. The exponent in the actual formula is called gamma since it is symbolized by

the Greek letter gamma (). For real CRT displays, gamma measures approximately 2.3 to 2.5. In

formal standards, gamma is taken as 2.2 but the difference here is small and easily accommodated bythe eye.

Proper gamma response happens almost automatically on CRT displays by virtue of the physics of their

operation. Unlike CRTs, digital displays such as plasma, LCD and DLP are inherently linear, not

exponential, devices and have to have their light outputs made exponential by their internal processingcircuitry. With these screen technologies, proper gamma response is accomplished by processing the

incoming signal through gamma tables. These gamma tables convert linear input levels into internal

levels that yield the desired exponential gamma response when fed to the display elements.

Many digital displays have selectable or adjustable gamma tables and curves, but factory defaultgamma tables do not always emulate standard CRT response. Non-standard tables can dramatically

alter image appearance, not always to beneficial effect. Just like excessively bluish grayscales, gammatables that boost middle- and high-range contrast at the expense of shadow and highlight detail are

common and help a display pop in a showroom comparison. But to achieve an accurate and pleasingimage, gamma response must also be adjusted to better match standard gamma response the response

for which video material is authored to look best.

Gamma response is most accurately and thoroughly characterized by measuring output at multiple IRE

levels, plotting the curve and estimating gamma from the shape of the curve (this is one of the mainpurposes of the multitude of gray fields and gray windows on Avia II, which can be used for precision

gamma adjustment by a professional installer). The patterns in the Gamma section provide a quick



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means of estimating gamma response. They compare the level of a gray formed visually by equalalternating areas of full-black and full-white with the value of an actual gray needed to match that

intensity. This procedure works because full-white remains the same intensity no matter the display

gamma, as does black, so by closely alternating equal areas of full-white and black, you can comparethat non-varying 50% gray against patches of actual 50% gray which are affected by gamma.

After that lengthy preamble, these patterns are quite easy to use: defocus your eyes and find the gray

patch which best matches the background. Weve included three basic gamma patterns, all of whichoperate in the same way. The backgrounds are intentionally coarse to help mitigate factors that couldchange the brightness of their 50% average intensity. Frequency response problems and scalers can

alter the brightness of the backgrounds, particularly if the background includes fine lines or details. The

coarser basic gamma patterns (Gamma Coarse and Gamma Coarse Striped) should be used firstbecause they are the most immune to such reprocessing effects. You should get similar values when

using those two patterns and, ideally, also with the fine-scale pattern (called simply Gamma). Any

result between 2.2 and 2.4 should be considered acceptable.



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GRAY FIELDS

Field 0500: Gray fields can be used to assess

uniformity and grayscale tracking.

Avia II supplies an extensive array of gray fields starting at 7.5 IRE and stepping by 2.5 IRE steps all

the way to 100 IRE. The menu-button labels multiply these IRE values by 10. For example, select

Field 0075 for the 7.5 IRE and Field 1000 for 100 IRE.

A professional installer can use these fields, along with some test equipment, to accurately measure orcalibrate such parameters as grayscale tracking and gamma. For the typical home user, however, their

uses are limited to what can be seen directly. Because these fields are completely uniform, an ideal

display screen will be completely filled by a single shade of gray. Real displays often have differencesin color and brightness over differing regions, especially when viewed from off-center angles.

Magnetization (with CRT sets), hot spotting (in projection sets) and color shifts (in projection and LCD

devices) are commonly seen irregularities.

7.5 IRE Field Pattern (Field 0075): If the brightness (black-level) control has been set properlyaccording to the patterns designed for that function (see the Levels section), this field should produce

the blackest black your set is capable of generating.

10 IRE Field Pattern (Field 0100): The very dark but not fully black 10 IRE field is particularlyuseful for detecting signal interference that may enter your system via poorly shielded cabling,connectors or the power system. Interference signals often appear as visible faint details against what

should be a perfectly even, very dark gray field. Observe this pattern with room lighting off and watch

for moving lines or faint images. AC hum bars, an interference at the power-line frequency, appearas a thick horizontal bar that slowly moves up or down the screen. Interference from extraneous video

signals can appear as faint, often recognizable, images superimposed on the dark gray background.



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GRAY WINDOWS

Important Note: Adjusting grayscale without a comparison reference gray leads to incorrect results. If

you dont have such a reference available, do not attempt to adjust grayscale as you can seriously upset

picture accuracy without proper instrumentation.

50 IRE Window: The lowest levels in thisimage have been boosted to clearly show thefaint calibration signals.

Window patterns are preferred over full-screen patterns for checking grayscale tracking. Manydisplays have non-uniform color when one compares different screen regions. These differences

between regions of a screen can confuse observers. By illuminating only a central rectangle, window

patterns minimize this confusion. Look for color changes as you step through the window patterns.Changes from neutral gray suggest a grayscale tracking error. Display gamma can also be determined

by measurements of the light intensities produced by a series of window patterns.

All Avia II window patterns have faint calibration patterns that can be used as a reality check to

ensure that initial settings of brightness and contrast have not changed and that any automatic imageadjustments made by the monitor are not affecting the entire image. Behind the window on the right

side are the moving black-level calibration bars familiar described in the Levels section. And to the left

of the main window a low-IRE scale extends in 1-IRE steps from dark gray (20 IRE) to barely abovefull black (8 IRE). The appearance of this calibration scale and its lowest levels may appear black

should not in any case vary as the intensity of the window changes. You may have to block off the glare

from the window itself to see whether this happens, especially at high-IRE window values.

As in the Gray Field patterns, the menu selections multiply the window IRE value by 10. The 10 IREwindow, therefore, is labeled Window 0100.

7.5-IRE Window (Window 0075): This pattern is full black and on an ideal display should appear

totally black and should match the darkness of the surrounding area, which is also 7.5 IRE. If the

window area is not completely black, the problem may be improper black level (brightness) setting,incomplete DC restoration in a CRT set, ambient light, or display technology limitations. CRT

projectors are desired for their very dark blacks. LCD, DLP and plasma systems can exhibit some lightleakage and fail to produce total blackness. The darkness of black is important in making a displayseem transparent.

2.5- and 5-IRE Windows (Window 0025 and Window 0050): These are blacker-than-black signals

and should appear as black as the 7.5-IRE window but not darker if the brightness (black-level) control

has been set properly.



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102.5-, 105-, and 107.5-IRE Windows (Window 1025, Window 1050, Window 1075): These arewhiter-than-white signals that should appear no brighter than the 100-IRE window (Window 0100).

If the contrast control is set too high, these windows may not reproduce cleanly.

20 IRE Window (Window 0200): Adjusting grayscale tracking usually involves switching betweenthe 100-, 20- and 7.5- IRE patterns while adjusting grayscale. Setting grayscale to match 6500K white

involves adjusting the color of white (100 IRE) and the color of near blacks (20 IRE) by adjusting theproportion of red, green and blue so that all grays from near-black to white match the color of standard6500K white. Typically two controls are provided for each primary color. Bias controls primarily

affect the dark end of the scale. Gain controls primarily affect the light end of the scale. The controls

interact so one must adjust them alternately. The human eye is very good at detecting disparitiesbetween colors, but poor at judging absolute color. Professional calibrators know this and always use

either a reference light source of 6500K or a colorimeter while making adjustments.

While viewing patterns for full white and near-black, bias and gain are set for each color to make near-

black and white as neutral in color as possible when compared against a reference light source or asmeasured by colorimeter. Ideally, once both ends of the grayscale are as neutral as possible, the display

is properly adjusted. Sometimes it is necessary to accept some error in the darkest portion of the scale

to achieve an overall more neutral image in the mid tones between 20 and 100 IRE.

Edge Transitions: If you examine the side edges of the central windows, youll see that three types ofhorizontal edge transitions are present. These can be used for testing system response for ringing,

bandwidth, group delay and the setting of the sharpness control. Transitions in the upper third of each

window are instantaneous and the sharp edge may create ringing (fringing effects) on some analog-connected systems. Transitions in the middle third have a slower-rising T2 characteristic with a

critical frequency of 6.75 MHz (the NTSC DVD frequency limit). The softest transitions, in the lower

third, are T2 with a critical frequency of 4.0 MHz (the NTSC broadcast limit).

The upper third, instantaneous transitions are very severe tests of system frequency response andtiming for displays hooked up via analog-video connections (composite, S-video, and component).

Digital connections such as DVI and HDMI should not produce any problems here unless the setssharpness control is set too high. The middle-third transitions are less severe and should be cleanly

reproducible by most home theater systems with sharpness correctly set. The transitions in the bottomthird of each window are significantly frequency-limited and should be cleanly reproducible on nearly

all consumer-grade video systems when sharpness is correctly set.



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HATCHES

Hatch Gray 80 235: The hatch patterns can beused for assessing screen geometry and

distortions as well as for measuring overscan

for images with different aspect ratios.

These patterns are used to detect geometric distortions that create any areas of the screen where the

horizontal and vertical lines do not meet at perfect right-angles or deviate from perfect parallelism.

Typical deviations from ideal performance in projection sets include barrel distortion (bulging outwardfrom the middle), pincushion distortion (a bulging inward towards the middle) and keystoning (a

narrowing of the image at the top or bottom). These distortions are perhaps best seen with the Hatches

marked Plain.

If a projector has separate optical elements for red, green and blue primary colors their alignment canbe checked with hatches as well. In particular, errors in convergence (the perfect alignment of red,

green and blue images on top of each other) can be exposed by using the hatch patterns.

Highest Resolution Possible on NTSC DVD: Designed for todays high-resolution, progressive-scan

displays, fine-lined hatch patterns are at the single-pixel limit of NTSC DVD resolution. The Very FineHatches have a grid thickness of only one pixel allowing keen observation of convergence. For displays

incapable of using high-resolution patterns, the other hatches have lines of two-pixel thickness.

Centering Ticks: Tick marks precisely indicate the center of the DVD pixel frame. Any offsets of the

image can be measured from here, which should coincide with the precise center of the screen.

Overscan Markers: These are the four sets of little arrowheads pointing away from the center andtoward the corners of where an image of the selected aspect ratio should be. They are spaced at

overscan intervals of 1% increments. Included among each series of overscan markers are two very

large markers (which may coincide with the hatch structure) indicating 5% and 10% overscan.Overscan markers for the following aspect ratios are supplied: 1.33 (4:3 standard TV), 1.78 (16:9

widescreen TV and HDTV), 1.87 (standard widescreen film), 2.0 and 2.35 (typical Scope widescreen

film aspect ratios). In the menus these aspect ratios are multiplied by 100 (133, 178, 187, 200 and 235).

To measure overscan at any particular aspect ratio, it is easiest to use one of corner-pointed marker sets.Start with the innermost small arrow and step outwards (remember to include the very large 5 and 10%

markers) counting down from 14 until you get to the edge of the image, at which point the number

youve reached, is the overscan percentage. A few percent overscan is typical, but with widscreencomputer monitors and a DVD played by the computer it is possible to have 0% overscan, a situation

that guarantees youll be seeing all of the recorded image.

Selectable Grid Intensity & Colors: Crosshatch intensities of 40, 60, 80 and 100 IRE (indicated in the

pattern name) as well as tinted and multicolor hatches are provided. Tinted grids make red, green, andblue approximately the same visual intensity so convergence adjustments in a projection system can be



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performed without turning off or capping color guns. Multi-color grids vary in color and reveal smallconvergence errors as motion of the grid as the colors change.

Adjustable Grid Spacing: Variable hatches (the ones containing Zoom in the menu) place grid

intersections exactly where they are needed. Use DVD player play, pause, and frame-advance controls

to select the grid spacing desired. The Zoom Hatches can also be used to assess how geometricdistortions, if any, change across the image.

Safe Action and Safe Title Areas: Coinciding with 10% and 5% overscan, these important framing

areas are indicated. To keep from losing important parts of the image on sets with excessive overscan,

program producers usually try to keep all dramatically significant images within the Safe Action area.The Safe Title area is the area of the screen in which subtitles are unlikely to be cut off by sets with

excessive overscan.



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HIGH MONOTONICITY STEPS

Steps by 4 16 to 235: Step patterns regularlylay out every luma level possible in DVD

video.

DVDs have their luma values encoded with 8-bit digital numbers. This produces a theoretical dynamic

range of 256 steps, which are numbered from 0 to 255. However, in technical standards full black is

defined to be at digital level 16 and full white at level 235. To accommodate signal overshoots whenconverting from analog to digital video and imperfect mastering processing, blacker-than-blackfootroom and whiter-than-white headroom are allocated digital levels 1 to 15 and 236 to 255

respectively.

Ideally, a display should be able to show each of these numerical values as a separate gray level. If the

display incorporates digital processing, those computations must also have sufficient internal precisionto represent all luma values 16 to 235 afterapplying the gamma-correction that makes the particular

display (LCD, plasma, DLP etc.) produce the correct light intensity gradations (see the Gamma Basic

section). Insufficient precision in this processing will cause some signal levels in the original input tobe indistinguishable on-screen from others and will thus create banding, contouring, and clipping

artifacts (see also the Ramps section and the Banding Check and White Gradient patterns in the

Miscellaneous section for additional banding/contouring tests). Unless there is digital processingcausing it, analog displays (CRTs) are not susceptible to monotonicity errors

Normal step patterns, even those in 5 IRE increments (see the Steps section) are neither fine enough in

level change nor monotonic (increasing or decreasing steadily without a jump, gap or repetition of an

earlier value) to completely test for preservation of digital values. The patterns in this section are forchecking monotonicity and processing bit depth.

There are five High Monotonicity Step patterns, each with the digital luma range it covers labeled on

the menu selection. The step size between each level is 2 (double), 4, or 1 (with three patterns covering

the entire luma range). The single-step pattern that runs from 16 to 235 tests the range from full blackto full white (Steps Single 16 to 235). The 1-to-254 pattern tests the entire legal digital range including

foot- and headroom. There is also a pattern that includes steps at the illegal but still encodable valuesof 0 and 255. DVD players that do not pass blacker-than-black signals will clip all values below 16 and

cause loss of the darkest portions of two wide-range patterns (Steps Single 0 to 255 and Steps Single 1to 254).

Standards-compliant material will have all its luma information confined within the 16 to 235 digital

range. However, mastering is not always perfect. Some DVD releases have white values well above the

standard 235 (that is, from 236 to 255). Such non-compliant discs can look brighter but also can inducesevere highlight clipping on many displays.



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High Monotonicity steps are best used by first verifying that the DVD player and processor arepreserving each step value. This is best done with an oscilloscope or waveform monitor since without

waveform verification any observed problems cannot be properly attributed to the player or the display.

Once player monotonicity is confirmed (the steps always increase in level from left to right and all stepvalues are present), visualobservation of a display reveals whether its allows it to render all luma

values. If not, some adjacent steps will become indistinguishable. That is, it will appear that a step has

received more than equal share of screen area. With the single-step patterns it can be difficult to see theindividual steps under any conditions, but the difficulty is compounded if the displays brightness and

contrast controls are improperly set.



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HORIZONTAL SWEEPS

To system test frequency response more completely, sweep patterns are useful. These provide

continuously varying frequency sinewave sweeps that test a continuous range of frequencies. In the

horizontal sweeps, the frequency varies from low to high from left to right across the width of the

pattern creating a series of increasingly tightly-spaced vertical lines as the frequency increases. Color-

component sweeps are also provided.

Y HSweep 350 675 polyphase: This

horizontal sweep spans 3.5 to 6.75 MHz andwhen seen in motion traces out a response

envelope on a waveform monitor.

This is an example of a luma (Y) sweep, here spanning 3.5 to 6.75 MHz. Like all Avia II sweeps, when

displayed on a piece of video test equipment called a waveform monitor, the signal is self calibratingand self-labeling. On a waveform monitor the bars at the top of the screen form lines indicating 3 and 6

dB signal loss, and the black and white areas on the left form the limits between which the amplitude of

the sweep waveform itself should fall. At the right of every horizontal sweep is a burst of themaximum frequency possible for that type of signal (6.75 MHz for luma and 3.38 MHz for the color

components). On a waveform monitor, the polyphase sweeps such as this one trace out a continuous

signal envelope at the highest frequencies, making good response measurements at those points

possible.

When viewed on a video monitor or TV, however, the sweeps let you easily see the effects on

frequency response of sharpness controls and of various pre-picked screen settings (movie, game, etc.).

If you want to actually measure response using these sweeps, the only thing you can do is estimate

where, if at all, the lines in the pattern mush together to create a gray of the same approximate intensityas the gray background. At that point, the response is reduced by some 12 decibels or more. However,

with any modern display, flat-panel or projection, and with any advanced hookup (analog component or

HDMI) it is unlikely that you will see any such attenuation, as both the luma and chroma response ofmodern equipment is more than adequate for standard-definition DVDs, like Avia II.



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To determine which sweep may be appropriate, the following table may be useful.

Sweep Name Start Frequency End Frequency Type

HSweep Cb 50 200 0.50 MHz 2.0 MHz Color component, fixed phase

HSweep Cr 50 200 0.50 MHz 2.0 MHz Color component, fixed phase

Polyphase HSweep Cb 50 338 0.5 MHz 3.38 MHz Color component, varying phase

Polyphase HSweep Cr 50 338 0.5 MHz 3.38 MHz Color component, varying phase

Y HSweep 50 250 0.5 MHz 2.5 MHz Luma, low frequencies, fixed phase

Y HSweep 100 400 1.0 MHz 4.0 MHz Luma, mid frequencies, fixed phase

Y HSweep 150 300 1.5 MHz 3.0 MHz Luma, mid frequencies, fixed phase

Y HSweep 250 450 2.5 MHz 4.5 MHz Luma, high frequencies, fixed phase

Y HSweep 350 675 polyphase 3.5 MHz 6.75 MHz Luma, highest frequencies, varying phase



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LEVELS

Black level, white level, grayscale tracking, and gamma response are the foundations of video imagereproduction. If these are improperly adjusted, highlight and shadow details may be obscured and

midrange contrast can be too bright or dark. The levels section contains two families of patterns for

setting black level (adjusted with the brightness control), and white level (contrast control): Black

Level Bars and Needle Pulses.

Black Level Bars

Black Level Bars: The three near-black barsare labeled here as well as having their

relative brightness boosted for clarity,

although they still may not be visible if this

page is printed or if your computer monitorsblack level is poorly set. On-screen, there is no

labeling and the bars slide back and forth

slightly to increase their visibility duringblack-level adjustment. These bars are also

contained in some Color Bars patterns.

Adjusting black level via a brightness control involves looking at the very darkest portions of an image.

To obtain the greatest contrast ratio a display can produce those parts of an image that are encoded as

full-black should be as dark as possible andany details just above full-black actually should appear onscreen, if only very dimly. The fundamental pattern used to adjust black-level/brightness is called Black

Level Bars and it looks like the illustration above, minus the labeling. It is very dark.

The three vertical near-black bars slide back and forth to increase their visibility. Their levels have been

carefully chosen. The leftmost stripe is 4 IRE below full-black. This blacker-than-black bar may not bevisible at all with equipment that does not pass such signals (see the High Monotonicity Steps section).

This is OK, since blacker-than-black signals should always appear as full black anyway. The middle

black level bar is a scant 1 IRE above the full black background. The rightmost black-level bar is 2 IREabove full black. The +1 and +2 bars are extremely close to black allowing a very precise indication of

proper black level. If a display's black level is set only 1 IRE too low the middle, +1 bar becomes

invisible against the full black background. Likewise if the brightness control is set 2 IRE too low, therightmost, +2 bar disappears into blackness.

With all four Black Level Bars patterns set the black-level/brightness control so that -4 bar (if there is

one visible) is the same black as the black background andso that the +1 and +2 bars are visible, the +1

barely so. Equipment with poorer shadow rendering or insufficient bit depth may have difficultyachieving both a black background and displaying the +1 bar.



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Black Level Bars Log: Added to the preceding

pattern is a log-step pattern with a set of near-

white bars contained within the topmost

segment of the steps. None of the near-blackand the near-white bars may be visible if this

page is printed or if your computer monitor hasbrightness and contrast poorly set.

The Black Level Bars Log pattern adds a log-step pattern to the basic Black Level Bars.

Logarithmically varying in intensity, the steps should appear to be equally spaced in brightness.

Contrast can be set using the near-white bars contained within the topmost segment of the steps. Forinformation on using the log steps and near-white bars in this pattern to calibrate contrast see the

Needle Pulses and Needle Pulses Log patterns below.

Black Level Bars + Varying Gray: Varying the

average picture level with this pattern tests

black-level stability.

Sometimes variations in the whole-screen average picture brightness or level (APL) affects the blackest

blacks. A compromise black level must often be set at intermediate average picture intensity. The actualAPL selected will vary with display behavior. The Black Level Bars + Varying Gray pattern allows the

user, while setting black level, to also set the APL to a level appropriate for the display. The right half

of the pattern can be varied from black to white using the play, pause, and frame-advance controls of

the DVD player. If a 90 IRE or brighter right half is chosen, the Avia standard white-level bars areadded to the test pattern to help detect overloads.

Modern digital displays retain black level much better than CRT displays, but even if a display has

perfect black-level retention, a variable APL black-level pattern is still beneficial. Selecting a low APL

can make the black level bars easier to see by reducing light scatter (especially with projection sets)while still placing more realistic demands on the display. Real images, as opposed to test patterns,

rarely span a total brightness range of only 2 IRE!

You can also use this pattern to testblack-level stability by playing it straight through and observing if

the black-level bars change in appearance. You might want to block off the right half of the image sothe mounting glare from the right side doesnt change the visibility of the black bars. Sometimes

automatic-picture enhancement features of a display will vary the black level deliberately.



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Black Level Bars + Steps + Varying Gray:The one-stop test pattern for setting brightness

and contrast, it contains all the features of the

previous patterns and adds gamma-trackingpatches to the grayscale steps.

This pattern contains all the features needed to accurately set brightness (black level bars) and contrast

(near-white bars) as well as to assess grayscale tracking (log steps) and gamma response (the stripedgamma patches). Grayscale tracking and gamma response are discussed below in the coverage of

Needle Pulses Gamma Log.

Needle Pulses

Avia II adds extra features to this classic

needle pulse test pattern.

The family of needle pulses patterns is based on the classic needle pulse pattern shown above. Simpleas it appears, this used to be a difficult pattern for CRT-based displays since the large full-white area

places sudden and extreme demands on a CRTs power supply. If the power supply were not up to it,

the increased demand would end up distorting the verticality of the two needle pulses, bending them.

This bending would be exacerbated if the sets contrast control were set too high because that wouldincrease the power being fed to the white region. So one method of setting contrast was to dial it up as

high as it could go without producing noticeable bending of the lines or blooming of the white area

(so that its upper borders with the black area and black line segments lost their sharpness). This was

never a very satisfactory method of setting contrast. Besides, no modern fixed-pixel technology (DLP,LCD, plasma) has power-supply issues that are stressed by the needle-pulse pattern and over-setting

contrast on these displays wont distort picture geometry. So instead of evaluating picture geometry toset white level nowadays you actually have to judge contrast!

With some features exaggerated for clarity, the most vanilla of the Avia needle-pulse patterns (called

simply Needle Pulses) looks like this:



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Needle Pulses: Levels near black have beenraised and those near full white lowered to

make the special features for setting black

and white level clearly visible.

Using this pattern alone to set black and white levels, you should adjust contrast so that you can see the

two left-most bars of the three vertical near-white bars next to the left needle pulse (they look gray in

the illustration). The third, right-most bar is actually whiter-than-white and may not be visible with anycontrast setting. This above-white bar can clip without endangering details of properly mastered

material. But if no contrast setting makes both of the left-most bars visible, the system is clippingimage details that are near white. With a digital or plasma display don't assume that lack of clipping(middle and left near-white bars both visible) is sufficient to ensure white level is correct. You should

also check grayscale tracking with the Needle Pulses Log pattern described further below.

Using Needle Pulses to set the brightness control operates in the same fashion. As with the Black Bar

Level patterns, set brightness so that you can see the two right-most vertical near-black bars next to theright needle pulse. The left-most near-black bar should be full black and invisible against the rest of the

top two thirds of the screen, which also should be full black. Both the near-white calibration bars and

the near-black calibration bars slide back and forth to increase their visibility.

As a bonus, this pattern contains two crossed horizontalstep patterns that allow you to gauge how

your system handles whiter-than-white (lower pair of steps) or blacker-than-black (upper pair of steps)reproduction. The dark steps in the black background cross at normal full black. The brighter steps in

the white background cross at 100% white. Depending on whether how much video headroom yoursystem has, you may or may not see the steps that go above white. A display with properly adjusted

black level shouldn't show the blacker than black portion of crossed steps at all. Viewed on a waveform

monitor, the steps indicate how the signal processing handles above-white and below-black details. You

can also use these step patterns to gauge whether your blacks are being crushed (less than half of eachof the upper step sequences pairs is visible) or whether your system is clipping before even full white is

reached (less than half of each of the lower step sequences is visible).



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Needle Pulses Log: This pattern adds a largegraycale-tracking section to the plain Needle

Pulses pattern. Note the inclusion of near-

white bars within the topmost segment of thegrayscale-tracking area. This pattern is also

supplied in red-, green- and blue-only versions.

This image has been enhanced for clarity.

In the Needle Pulses Log pattern you get everything that was in the plain Needle Pulses pattern plus a

large logarithmic steps area for visual assessment of grayscale tracking. Although it doesnt look like it

from the above tweaked image, on-screen the steps exponentially increase in intensity. The steps shouldappear on-screen to be equally spaced in brightness and should remain the same shade of gray if

grayscale tracking is correct. If grayscale tracking is poor, the color of gray may differ among steps.

This pattern feature is particularly useful while setting white level on digital or plasma displays. On

some of them, grayscale tracking becomes poor even before white level is raised to the point ofclipping the peak whites. As a consequence the contrast control may need to be kept below the point at

which grayscale tracking deteriorates. Look for this by observing the log steps while adjusting contrast.If you see a color shift in the steps or clipping of the faint near-white level bars in the topmost step

segment, white level has been set too high (see Needle Pulses above for coverage of clipping).

Needle Pulses Gamma Log: Though it doesnt

look like it here, the average intensity of thehorizontal lines in the gamma steps should

equal the intensity of the log step to its right.

This image has been enhanced for clarity.

The last needle-pulse pattern, Needle Pulses Gamma Log, has everything in Needle Pulses Log plus, atthe left side of the log steps, there are gamma-check steps for visual verification of gamma response.

Viewed from a distance with blurred vision, the average intensity of the lines in each gamma step

equals the brightness of the log step immediately to its right. The gamma steps and log steps should

therefore change in intensity together as they run from light to dark (see the Gamma Basic section)Important Note: Caution should be taken while interpreting gamma steps here. Scalers, including the

progressive-scan and HD-conversion systems within DVD players, sometimes alter the brightness of

fine lines. If such is the case, the gamma steps will not match the brightness of the accompanying logsteps. You can still use the gamma steps but look for them to darken and lighten in only proportion to

the log steps rather than identically matching them in brightness. For a method to estimate your

displays gamma that does not depend on very fine lines, see the Gamma Basic section.



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MISCELLANEOUS Banding Check

Banding Check: Look for any disturbances inthe smoothly changing portions of the image.

Banding will produce oval-shaped arcs or

even stripes centered around the affectedcolors.

Banding or contouring is a digital-video phenomenon that prevents gradients areas of the picture

where the brightness is changing very gradually from being reproduced smoothly. It can occur in anystage of digital-video production, from the camera output to the display. Visually, banding produces an

abrupt change in a gradient that is usually seen as a distinct border, or borders, between the brighter anddimmer portions of the gradient. Banding is often seen in wide expanses of gradually changingintensity, such as a blue sky near the horizon or a cloudless sunset. Banding is perhaps most obvious

when such scenes are faded in and out to black as the banding border(s) move across the image and call

attention to themselves. You can see a dramatic example of this with the White Gradient pattern in this

section.

The Banding Check pattern will at least let you find out if your video chain between DVD player and

display is producing additional banding discontinuities besides those which may already be contained

in normal program material. Look for any discontinuities in the otherwise smoothly changing areas of

the image. Banding will produce oval-shaped arcs centered around the middle of every color that isaffected. Usually if one of the primary colors has banding, white will have banding as well.

If you see banding on this pattern, to narrow down the culprit between DVD player or display you have

to swap out each unit separately for a unit known to be free of banding. Theres little you can do

otherwise to eliminate banding. Nothing can be done if it is already encoded into the program material,which it too frequently is. Theres a good reason why banding happens so often with movie DVDs

actually its not so good but explaining it completely is beyond the scope of this manual.

Severe banding simulated with a photo-

processing program. The amount of banding isthe same for each color but note that its

visibility varies.



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MISCELLANEOUS Bias Light

Bias Light: If you are watching on a relativelysmall screen, you can use this pattern to adjust

the amount of light illuminating the wall

behind the display

Illuminating the wall behind a smaller video display reduces eye fatigue by moderating the eyes light

sensitivity. A small screen (one spanning less than 30 degrees width in your angle of view) does not

cover enough of your viewing field to control eye light sensitivity. If you have a darkened viewing

room as all critical viewers do your eyes will adjust to the much larger dark surroundings andbecome overly sensitive to the relative high brightness of the video screen. Under these conditions, the

display is akin to a flashlight shining directly into your eyes. Large front projectors and flat-paneldisplays can cover enough of the visual field to control your light sensitivity and do not require

backlighting.

White lighting of the wall behind a display so that reflects with a brightness of 5 to 10 percent of the

maximum screen brightness moderates the eye sensitivity enough to avoid viewer fatigue with smallerscreens.Afteryour display has been calibrated for white and black levels (contrast and brightness),

adjust your backlighting so that its apparent brightness behind the display falls somewhere between the

5 and 10-percent levels shown in this pattern.



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MISCELLANEOUS CHIP CHART

Chip Chart: The crossed steps test grayscalewhile indicators for shadow detail and white

level clipping are in center of pattern

separating the steps. The steps should onlyvary in intensity and not in color.

This is the electronic equivalent of a camera view of a log-reflectance paint-chip chart. It, like thepatterns in the step, ramp, gray window and gray field sections, allows visual checks of grayscale

tracking as well as black and white level. Such crossed step patterns were less useful with CRT

projection because of that technology's propensity to shift color slightly between one side of the screen

to the other. The left/right color shifts troubled observations of grayscale tracking so much that steppatterns fell out of favor in home-cinema setup. Digital projection systems, with their better side-to-

side color uniformity, once more allow chip chart usage.

This chip charthasan 18% brightness background, not18% signal intensity. Such a background is

similar to the 18% gray reflectance cards used by photographers to judge exposure settings. Thecrossed steps run from 0% (black) to 100% (white) signal intensity (from digital 16 to 235 see the

High Monotonicity Steps section). All the steps should vary only in intensity, not in color.

In the center are a black band and a white band. Within each of these bands there are five nearly-square

stripes testing near-black and near-white performance. These internal stripes vary in intensity from

left to right. This allows finer testing of shadow and highlight detail performance. The left-most stripeis dimmest in each series of five stripes. The near black stripes are at 1, 2, 3, 4, and 5% intensity. The

near white stripes are at 95, 96, 97, 98, and 99% signal intensity. On a display with good shadow andhighlight rendering and that has been properly calibrated for brightness and contrast all of these the

near black and near white stripes should be visible, if barely.



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MISCELLANEOUS CUE Check: Blue, Green, Red, RGB

CUE Check RGB: This pattern allowsdetection of any color-upsampling problems in

a DVD player.

Color information on DVD is undersampled both vertically and horizontally. That is, there is

deliberately less resolution in colors than in brightness. During reconstruction of the image in playback,a reconstructed color value must therefore be assigned to each luma pixel. In other words, the recordedchroma information is upscaled or upsampled by the DVD player. Unfortunately, some players

produce an artifact during the chroma upscaling process known as Chroma Upscaling/Upsampling

Error (CUE). By and large, substantial progress has been made regarding CUE since its discovery by

equipment reviewers a few years ago. Most recent DVD players are free of CUE.

Chroma information is correctly downsampled during DVD encoding using two different methods.

One method is used for progressive-scan material, the other for interlaced material. In order to avoid

CUE, a DVD player must select and use the chroma upscaling method that undoes the method that was

used during downsampling. Unfortunately, many DVD players only implement one method the oneused for interlaced material. If the original downsampling method was progressive and the interlaced

method is used for upscaling, the resultant upscaled chroma is corrupted. Most films on DVD are

progressive material so this problem can frequently arise.

Other causes of chroma upscale errors also exist, but the cause described above is probably the one ofgreatest interest because it affects critically viewed film material. On smaller displays, CUE artifacts

are minimally visible, but on a large, high-resolution home cinema display, CUE can be seen as jagged

edges along intensely colored diagonal edges and every-other-horizontal-line changes in color intensityin gradients. You may also see weird fringing effects, especially with sharp, horizontal or near-

horizontal edges containing highly saturated colors.

The CUE tests in Avia II are for detecting use of interlaced chroma upscaling during display of

progressive material. This simulates the chroma upscale error that may be seen on film-based material.

Diamond Stacks: Columns of diamond shapes with internal gradients allow visualization of CUEinduced jaggedness of diagonal edge transitions. If CUE is present, the diagonal edges of the diamonds

nearly halve in resolution and will have a distinctly non-smooth, jagged appearance.

Chroma Sweeps: Some video processors are able to hide CUE because they undersample chroma. This

reduction in chroma detail filters out finer chroma details and, as a side effect, also hides CUE. Chroma

filtering is detected with the vertical and horizontal chroma sweeps in this pattern. If filtering is present,the short colored lines making up the chroma sweeps at the top and left of the pattern will become



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indistinct short of the endpoints of the sweep at the far right and bottom left. Separate CUE charts areprovided for each primary color so you can test whether the filter or upscale processing affects any of

them differently.



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MISCELLANEOUS Hot Spot: Lower, Middle, Upper

Hot Spot Upper: Caught in mid-test, thispattern allows you to gauge the severity of a

projection systems hot spot.

A flat-panel display does not produce a hot spot, an area that is brighter than the remainder of the

screen. But many projection systems do produce them as a byproduct of the projection optics. If the hotspot is overly prominent, image fidelity suffers. On rear projectors, the hot spot usually appears near

the center of the screen. On front projectors, the hot spot location varies with projector and viewerpositions. This pattern is used to gauge hot-spot severity. Patterns are available for high-, middle- andlow-positioned hot spots.

These are animated tests and consist of a compensatory cold spot at the specified location. Its

coldness progresses as the test proceeds, with the test patterns spot getting darker by steps. To use

the patterns you will need to choose the one that matches the position of your displays hot spot.

First, estimate your displays hot spot (you can get a feel by playing some of the patterns in the GrayField section or the Uniformity pattern in the Miscellaneous section) and select the Hot Spot test that

you think matches your hot spot location. Let the Hot Spot test play through until you can easily see the

dark spot of the pattern. Use a differently positioned Hot Spot pattern if your displays hot spot and the

dark spot of the pattern do not coincide (the match doesnt have to be perfect). Also, change yourviewing position to center your projectors hot spot with the patterns dark spot. Play the selected

pattern again, using your DVD players slow-motion or frame-stepping controls to slow it down, until

the screens hot spot and the patterns cold spot compensate for each other and the center of thecombined hot/cold spot is approximately equal to the brightness of the image in the corners. The

number on the pattern at that point is the percentage by which your displays hot-spot brightness

exceeds corner brightness.



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MISCELLANEOUS: Overscan

Overscan: Testing whether youre getting the

whole recorded image is easy with this

pattern.

Television viewers expect the pictures to cover the entire surface of their displays, hence the frequent

dissatisfaction with letterboxing bars with widescreen movies. Overscan in televisions helps fill a

screen by allowing a portion of the picture to extend beyond the edge of the screen the picture thus is

made larger than the screen used to display it. While this keeps the image edges hidden it also losespart of the picture. Overscan has traditionally been set too high since changes of the scanning behavior

of CRTs could make the image edges visible as the set aged. Even modern flat-panel displays that, intheory, should not need to overscan at all, usually have overscan of a few percent.

Too much overscan can hide a great deal of a picture. Low quality CRT televisions can lose as much as

10% to 15% of image along each dimension. That means as much as 25% of the original picture area

is lost beyond the edges of the display. A good quality display only overscans 3 to 5% to hide imageedges. Critical viewers demand displays with minimal and stable overscan so they can see as much of

the picture as possible. Video producers compensate for the presence of overscan by keeping important

material in the central portion of the display. The safe action area is the central 90% of the image and

most important movement is kept to within this portion of the picture. A safe title area is 10%smaller still and important textual information, like subtitles, is kept within this area. This test pattern

lets you measure the amount of overscan, which is present on each edge of a display. Start with the

innermost rectangle and count down from 15 as you move outward, rectangle-by-rectangle, until youget to the edge of the picture. The number youve reached at that point is the overscan percentage for

that edge. It is common for the overscan not to be equal on all sides of the image, especially if there is

Pixel Cropping occurring (see the pattern for Pixel Cropping in the Miscellaneous section). Thenumbers are half as large as the overall inset because the pattern measures for each edge separately. The

safe-action area is within the 5% rectangle and the safe-title area is within the 10% rectangle. A quick-

and-dirty confirmation that you have either uneven overscan from edge-to-edge or that you have nooverscan at all is to note whether the corners of the large diamond are visible and not cut off (no

overscan, as in the image above) and, if they are cut off, whether they are asymmetrical.



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MISCELLANEOUS Pix YC Delay

Pix(el) YC Delay: You can measure the degreeof synchronization of chroma and luma with

this pattern.

The chroma (C) and luma (Y) parts of a video signal travel through separate circuits in a display and

this difference can result in the signals not arriving simultaneously at the screen. Displays must contain

YC delay circuitry to equalize the travel times for the signals since otherwise they would shift inrelation to each other on screen. This pattern allows visual measurement of YC delay errors if the errorsare one pixel or more. Note: visible YC delay errors are rare in correctly hooked-up flat-panel and non-

CRT projection sets, especially if component or digital (HDMI) connections are used.

A traditional red/yellow stripe YC delay pattern is on the right side of pattern. Inspect the left and right

edges of the red stripes to detect the presence of Y/C errors. If there is no error, both the left and rightedge transitions between yellow and red will appear identical. If a YC error is present, the change in

color does not coincide with change in brightness and the edge transitions will appear different.

The red, green and blue patches in the pattern also allow numerical measurement of YC delay errors if

the errors are one pixel or more. Each color patch is paired with a gray rectangle. For each color, lookat the leftedge of the color patches and find the patch that vertically aligns with the leftedge of its

paired gray patch. The number next to the best-aligned patch pair is the microsecond of error in the

luma delay. A perfect display has 0 error. A positive error means luma was delayed too long. Anegative number indicates the luma was insufficiently delayed. In addition to the three primary colors

(red, green and blue), you can measure Cr and Cb color-difference signal delays.



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MISCELLANEOUS Pixel Cropping

Pixel Cropping: You can measure how muchyour player cuts off the edges of the image

using this pattern and a suitable monitor.

This pattern measures how much image is cropped by a DVD player. Dont confuse pixel croppingwith overscan. Overscan is a display-device property that hides peripheral image areas by positioning

them beyond the edges of your display. On some CRT and projection sets, reducing your displays

vertical and horizontal raster size can bring overscanned image areas back into view. In contrast, pixelcropping is a DVD player properly in which it omits part of the original 720 x 480 pixel image (16:9

widescreen images such as on Avia II are 720 x 405 pixels). It cannot be corrected, if found. Because

pixel cropping is usually hidden by display overscan, most viewers never know that pixel cropping isremoving part of the picture, though less than typical overscan.

The maximum active line duration for NTSC video signals is not long enough for the entire 720-pixel

width of an image to be displayed if the player also conforms to the MPEG-2 encoded-bandwidth

limits. As a result, a DVD players NTSC video output typically crops about 9 pixels from the 720width of an image. The degree of cropping may vary from 6 to 12 pixels and may be on just one edge

or taken from both left and right edges, possibly unequally. It is possible for a DVD system to display

the entire 720 pixel wide image, but doing so requires circumvention of either NTSC timing or MPEG-

2 bandwidth limits. For example, computer DVD playback systems often can display the full 720 pixelwidth image on a computer monitor because the RGB video signals to the monitor need not follow

NTSC timing limits.

The Pixel Cropping pattern measures how many pixels are missing from each edge of the full 720 x

405 pixel widescreen image. It is usable only with displays with 0% overscan or on those devices(mainly professional CRT monitors) that can be set to underscan a video image so that the raster

doesnt fill the screen on any edge. First set your display to underscan mode (reduce vertical and

horizontal size enough to make raster edges visible). Along each edge of this pattern you will see ajagged diagonal line. Each segment of the jagged line is 1 pixel further from the frame edge. Markers

indicate which dash segments are visible when 0, 5, 10, 15 and 20 pixels have been cropped from an

edge. Find the outermost visible dash segment and read the markers to measure pixel cropping.On a waveform monitor, the figures in the corners appear as faint trapezoidal shapes. Two markers areprovided at each end. The outer markers are the ones actually examined from cropping. The inner

markers are for comparison. The sloped side of the markers should extend all the way down to

baseline if there is no cropping. If cropping occurs, part of the sloped side is cut off. Note the heightabove baseline at which the slope resumes then compare against the slots in the markers, which

indicate heights for 5-, 10-, 15- and 20-pixel cropping.



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MISCELLANEOUS Rainbow Dither: 2:3 and Video

Rainbow Dither 2:3: These patterns can revealif image motion overstresses the systems

ability to produce smooth gradients. You can

also detect the rainbow fringing in projectorsthat use color wheels.

Some digital displays (and video processors) have insufficient numerical precision in their processing

to represent all luma values on-screen. A combination of spatial (blurring) and temporal dithering

(smearing over time) can increase the apparent bit depth, smoothly rendering gradients during still

images but image motion dramatically reduces the effectiveness of spatial and temporal dithering.During motion, bit depth may plummet and create visible contouring or banding. On live material, one

sees such problems during camera pans. The Rainbow Dither test pattern uncovers temporal-ditheringmotion artifacts at various image-motion velocities. The pattern also helps detect color-separation or

rainbow artifacts on sequential color displays, such as DLP projectors using color wheels.

The Rainbow Dither patterns are supplied in both video-motion (Rainbow Dither Video) and 2:3-pulldown (Rainbow Dither 2:3) film-motion versions. Moving placards in the pattern indicate velocity

of motion in pixels/video field or pixels/frame, respectively. The patterns start without any motion so

that the still image may be compared to performance during motion.

The gray, dark gray, and flesh-tone spheres in the pattern possess smoothly contoured gradients. Theseglide across the screen and test bit depth performance at varying velocities. Better performing displaysavoid contouring up to higher velocities. Banding/contouring can appear in various ways, but they all

have in common a loss of smoothness of a spheres shading, including, in extreme cases, a reversion to

concentric circles.

Rainbow artifact or color separation artifact can be induced if a display sequentially presents the color

components of an image. During eye motion, image details may visibly break into separate red, green,

and blue images. The color-separation artifacts are less visible as the color-sequence rate increases.Watch for color separation artifacts by following the spheres across the screen while also paying

attention to the three vertical white bars in the pattern. As velocity increases you may see the bars

separate into different colors. Color-wheel speed has a dramatic effect on how high the pattern velocitygets before one sees color separation.

It is normal to see differences in the smoothness of motion when comparing video with the 2:3-

pulldown pattern. The latter usually produces a more jerky appearance when in motion. Activating yourplayers pause or frame-advance controls can also reveal differences. It is common for the 2:3

pulldown pattern to produce a much cleaner still frame, especially on a progressive display, since the

interlaced video patterns double-field structure can pull apart the spheres and boxes at high velocities(their positions change between fields as well as between frames).



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MISCELLANEOUS Tricolor

Tricolor: Use the supplied color filters to viewthis pattern, which allows hue and saturation

optimization with all three primary colors

simultaneously, and a four different intensitylevels.

This pattern is essentially a multi-level, animated version of the color checkerboard pattern in the Color

Bars section. Just as with the color bar signals in that section, it is used in conjunction with the supplied

color filters to set hue and saturation controls. After youve set the brightness (black-level) and contrast(white level) controls with patterns in the Levels section, while viewing the pattern through each of the

filters separately, adjust the hue and saturation controls to smooth the appearance of the flashingrectangles in each of the three color columns and in the four signal-brightness rows simultaneously.

Unfortunately, with most displays complete filter-viewed smoothness is usually not possible. But with a

little back and forth changing of the color filter you are looking through and by repeated alternating

adjustments of the hue and saturation controls (and possibly the contrast control, which might also havean effect), it should be possible to get pretty good compromise performance in two of the three color

columns. Make sure that one of them is the blue (leftmost) column and that your adjustments dont

throw off the color of yellow when the pattern is viewed without any filters (making yellow too orange

or green, for example).It is also desirable but unlikely that youll be able to optimize the screen simultaneously for the four

brightness levels, which produce four distinct bands of intensity across the width of the pattern. But

aim to get the three lower intensity levels as smooth as possible and let the highest intensity level fall

where it may. This will give the most satisfactory color reproduction with typical images, few of whichcontain color intensities as high as those in the top row.



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MISCELLANEOUS Uniformity

Uniformity: This pattern takes advantage ofyour eyes ability to spot small picture faults

when they are in motion.

The Uniformity pattern is a visual test of how well a display maintains uniformity. Screen uniformityproblems such as side-to-side color shift on CRT projectors, imperfect optical integrators in digital

projectors, uneven panel-bias voltages in plasma displays, and hot spotting are all easily detected usingthis test pattern. The test also checks for stuck or dead pixels on fixed-pixel displays.

Two dots revolve in opposing directions in front of a succession of black, gray, white, red, green, andblue backgrounds. To use this pattern allow your eyes to follow the motion of one orbiting dot. Pay

attention to the background as your eyes shift around the screen. The pattern background is uniform

and devoid of features. Uniformity problems appear as screen areas differing from the rest of the

screen. You may notice that one corner of the screen is brighter, or one side is a different color of gray,or the center of the screen is much brighter. These are all due to screen and/or projector uniformity

problems.

Pixels in flat-panel displays stuck in the on or off position are readily detected as tiny anomalous spots

if one tests using all six color backgrounds. Look for any pixels that fail to change color in step withthe rest of the pattern background. While some bad pixels are acceptable in computer and presentation

applications, the more critical viewing needs of a home cinema practically demand the projector have

zero dead or stuck pixels.

If a display has slow recovery time, a faint trail may be seen behind the orbiting dots. This is mostlikely to be seen on LCD panels. Counterrotation of the two dots also aids observation of color

separation artifacts. As your eyes track the motion of one dot, they move relative to the other dot. You

may see the other dot may break up into separate red, green, and blue elements on systems thatsequentially display the three primary colors, such as DLP projectors with color wheels.



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MISCELLANEOUS White Gradient

White Gradient: This original still frame isprobably the best this pattern will ever look. It

has proven impossible to encode it on DVD

withoutsevere banding artifacts.

This simple looking pattern is extremely difficult and very likely impossible to encode cleanly on

DVD. The original consists of an extremely smooth gradient starting at from full white at the lower

right diagonal and wrapping smoothly around to half-white on the other side of the diagonal. In theimage above it looks very smooth but on an enlarged computer display you can see the individual steps

of the gradient as evenly spaced spokes pointing toward the center of the image.

Now comes the hard part: after dwelling on this frame for two seconds, the pattern fades down in

discrete steps lasting 10-frames each and perfectly aligning the individual gradient spokes with thespokes in the layer before it until what was full white is only at half white and what was half-white is

at black. Then the process reverses with a fade-up.

The pattern shouldlook like what it is: a simple partial fade down then a fade up. The spokes, if any,

should not move. But the way digital video is typically encoded combined with the additional MPEG-2encoding for the DVD system produce instead a spectacular case of banding that no DVD player can

cure. What was originally intended as a sensitive test for player or display banding is actually a forceful

demonstration of the need for improved video-encoding standards. The best time to have adopted newstandards was with the introduction of HD-DVD and Blu-ray technologies. But were going to have to

wait until at least the 2nd generation of these discformats (not just the players) to see any improvement

in the White Gradient and with similar images in real program material, such as expanses of sky andsunsets that fade in and out.



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MOTION & MOVING ZONE PLATES

Moving Zone Plate Film 2:3: Among otherthings this pattern will test a DVD players

ability to recognize pulldown flags and to

produce a smooth progressive-scan image.

Deinterlacing and scaling performance are central to the success of todays progressive-scan displays.

Not only must a video processor deinterlace (transform an interlaced signal to a progressive one)

appropriately, but it must also scale the image to the target display resolution, especially amongdigitally connected DVD players (with DVI or HDMI outputs). Both processes potentially degrade

image resolution. The Moving Zone Plate patterns test scaler and deinterlacer performance over a range

of velocities and directions. There are tests in 2:3-pulldown film motion (Moving Zone Plate Film2:3), interlaced video motion (Moving Zone Plate Video), and 2:2-pulldown used for progressive film

material shot at 30 frames/second, as is frequently done for TV commercials (Moving Zone Plate Film

2:2). Aside from the types of motion, all three tests are identical.

Motion Indicators: The first line of text in the pattern indicates the current type of motion. The 2:3film motion pattern has the proper 2:3 pulldown flagged and tests the ability of a DVD player to detect

and properly follow pulldown and repeat flags. Deinterlacing within a DVD player should be without

loss of lock during film motion. If the interlaced output of a DVD player is used to feed an external

scaler, the scalers cadence detection is tested. The Video and 2:2 motions are not flagged on disc andtest cadence detection rather than flag detection.

Motion in horizontal, vertical, diagonal, and circular directions are all tested. Velocity is indicated in

pixels/frame in the horizontal (dx) and vertical (dy) directions (+x is toward the right, +y is upward).As each direction is tested, velocity accelerates. Motion was animated in whole-number pixel

increments to avoid moir effects that would have occurred with fractional pixel motions. Even so it is

common for the display to look degraded only on odd-numbered velocities, at least for the lower range

of velocities. You can gauge image degradation by noting the clean appearance of the pattern whenthere is no motion, as at the start.

Zone Plate: A circular zone plate spanning luma frequencies fr

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