Pixel- In digital imaging a pixel is a physical point in a raster image or the

smallest addressable element in a display device so it is the smallest controllable element of a picture represented on the screen. The address of a pixel corresponds to its physical coordinates. The term pixel is actually short for Picture Element. These small little dots are what make up the images on digital. The screen is divided up into a matrix of thousands or even millions of pixels. Each pixel can only be one colour at a time. However, since they are so small, pixels often blend together to form various shades and blends of colours. The number of colours each pixel can be is determined by the number of bits used to represent it.

Resolution - Refers to the sharpness and clarity of an image. The

term is most often used to describe monitors, printers, and bit-mapped graphic images. Bitmap images are composed of pixels. Image resolution is simply the number of Pixels Per Inch (PPI) in the bitmap grid. There are two aspects to every bitmap image - its size (width and height in inches) and resolution (the number of pixels per inch). These two factors alone determine the total number of pixels in an image. Some of the typical resolutions include; 256x256 - Found on very cheap cameras, this resolution is so low that the picture quality is almost always unacceptable. This is 65,000 total pixels. 640x480 - This is the low end on most "real" cameras. This resolution is ideal for e-mailing pictures or posting pictures on a Web site. 4064x2704 - A top-of-the-line digital camera with 11.1 megapixels takes pictures at this resolution. At this setting, you can create 13.5x9 inch prints with no loss of picture quality.

The more pixels there are in an image, the more detail the image can be displayed with. The fewer pixels there are in an image, the less detail the image can be displayed with. There are two ways to display an image - on screen and in print. The standard for screen displays is 72 PPI. The standard for Print is 300 PPI.

Screen Ratios - The aspect ratio of a screen or image describes the

proportional relationship between its width and its height. It is commonly expressed as two numbers separated by a colon, as in 4:3 and 16:9. The most common aspect ratios used today in the presentation of films in movie theatres are 1.85:1 and 2.39:1. Two common video aspect ratios are 4:3 (1.33:1), the universal video format of the 20th century. And 16:9 (1.77:1), universal for high-definition television and European digital television. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras 16:9. This is important as many DSLRs are being used to shoot video due to the quality of their internal sensors and superior lenses. With television, DVD and Blu-ray Disc, converting formats of unequal ratios is achieved by enlarging the original image to fill the receiving format's display area and cutting off any excess picture information (zooming and cropping). By adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio.

Pixel Aspect Ratio describes the relationship between the width and height of a single pixel. Different pixel aspect ratios are the reason why two video images with identical frame sizes can appear as different sizes on screen. If width = height, then the pixel is square and the aspect ratio (width÷height) = 1.0.

Frame Rate - The human eye and its brain interface, the human

visual system, can process 10 to 12 separate images per second, perceiving them individually. Early silent films had a frame rate from 14 to 24 FPS which was enough for the sense of motion, but it was perceived as jerky motion. Persistence of vision was a commonly-accepted although somewhat controversial theory which states that the human eye always retains images for a fraction of a second on the retina (around 0.04 second).

Frame Rate tells you how many frames per second there are when recording or playing video/dvd. Video cameras in Europe use 25 frames per second (fps). In USA & Japan 29.97fps or 30fps is used. Animation works by recording each frame individually (e.g. with a stills camera) and then playing them back at a frame rate. They also often work with a lower frame rate (e.g. 12fps) so less frames are needed for the same length video clip. Frame rate is most often expressed in frames per second (FPS) and is also expressed in progressive scan monitors as hertz (Hz).

Video Formats – A video format defines the way in which video

is recorded and stored. It normally specifies: Codec/Compressor, Frame Rate, Frame Size, Frame Aspect Ratio, Pixel Aspect Ratio, Scanning Method. Some common formats are DV, HDV, AVCHD. Tape based formats such as DV and HDV can be transferred to a computer for editing via firewire. File based formats such as AVCHD are already stored as files and can be transferred to a computer for editing via USB or card reader. File-based formats may need to be converted during or after transfer to compatible with editing software.

Compression – Codec is short for coder-decoder and describes

the method in which video data is encoded into a file and decoded when the file is played back. Most video is compressed during encoding, and so the terms codec and compressor are often used interchangeably.