Shading Correction; Building Shading Image In Format_7 Modes; First Example; Second Example - AVT Pike Technical Manual

Description of the data path

Shading correction

horizontal
vertical
Shading correction is used to compensate for non-homogeneities caused by
lighting or optical characteristics within specified ranges.
To correct a frame, a multiplier from 1...2 is calculated for each pixel in
1/256 steps: this allows for shading to be compensated by up to 50%.
Besides generating shading data off-line and downloading it to the camera,
the camera allows correction data to be generated automatically in the cam-
era itself.
Note
• Shading correction does not support the mirror func-
tion.
• If you use shading correction, don't change the mirror
function.
• Due to binning and sub-sampling in the Format_7
modes read the following hints to build shading image
in Format_7 modes.

Building shading image in Format_7 modes

Binning/sub-sampling is always done after shading correction. Shading is
always done on full horizontal resolution. Therefore shading image has
always to be built in full horizontal resolution.
Binning/sub-sampling is done in the sensor, before shading correction.
Therefore shading image has to be built in the correct vertical resolution.
Note Build shading image always with the full horizontal reso-
lution (0 x horizontal binning / 0 x horizontal sub-sam-
pling), but with the desired vertical binning/sub-
sampling.

First example

4 x horizontal binning, 2 x vertical binning
build shading image with 0 x horizontal binning and 2 x vertical binning

Second example

2 out of 16 horizontal sub-sampling, 2 out of 8 vertical sub-sampling
build shading image with 0 x horizontal binning and 2 out of 8 vertical
sub-sampling
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