Image Filtering

Comparison of ISP HWvs

Almalence SW filters

+

Tasks sharing between ISPAnd

Almalence Imaging Libraries

Features chart

ISP HW Almalence SW

Multishot-compatible No Yes

Lens shading taken into account

Rarely Yes

Easily configurable No Yes

Typical ISP pipeline

Sensor ADCChroma

sub-sample

RGBto

YUV

Gammacorrect Sharpen JPEG

encDenoiseColor-space

convert

RAW

Opticalclamp

De-bayer

FaultyPixel

correct

Lensshadingcorrect

Culling&

Binning

Blacklevelsub

Scale

Red-tinted blocks are filters

ISP function with Super-Resolution

Sensor ADCChroma

sub-sample

RGBto

YUV

Gammacorrect Sharpen JPEG

encDenoiseColor-space

convert

RAW

Opticalclamp

De-bayer

FaultyPixel

correct

Lensshadingcorrect

Culling&

Binning

Blacklevelsub

Scale

SR processing

JPEGenc

Denoise

Align

Fuse

De-ghost

Enhanceedges

SR processing includesDenoise and Sharpening.

Standard filters should be turned off to preserve image data needed for SR

-SR utilizes image data preserved due to absence of filters-SR replaces the filters with better ones

Real life comparison

Example images below have been taken with Galaxy Nexus

Stock firmware

Jelly Bean Android

Noise filter – HW ISPLens shading correction not taken into account

Center

Corner: noise outbursts

Noise filter – AlmalenceLens shading taken in account

Center

Corner

Noise filter – AlmalenceEasily configured (API accessible from application layer)

No filtering

High filtering

Little filtering

Noise filter – Almalence

Filtered with HW:Some noise remaining,Some details lost

Filtered with Almalence NF:Complete removal of noiseDetails remain

SW flexibility allows for more complex algorithms

Sharpening filter – HW ISPDownscaled full image looks good

Close look – oversharpening evident (halos)

Sharpening filter – Almalence

Close look – edges are enhanced, no halos

Super-resolution compatibilitySR result with pre-filtered images: lossof details, over-sharpen exaggerated

SR result with post-filtering