ALLIED Vision Technologies Stingray F-504 - Manual (Page 132)

Description of the data path
STINGRAY Technical Manual V4.4.4
130
Shading correction
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.
Building shading image in Format_7 modes
horizontal 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.
vertical Binning, sub-sampling and mirror are done before shading correction. There-
fore shading image has to be built in the correct vertical resolution and
with needed mirror settings.
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 8 horizontal sub-sampling, 2 out of 8 vertical sub-sampling

 build shading image with 0 x horizontal sub-sampling and 2 out of 8
vertical sub-sampling
Note

• Shading correction does not support the mirror func-
tion.
• If you use shading correction with mirror function,
activate the mirror before building shading image.
• Due to binning and sub-sampling in the Format_7
modes read the following hints to build shading image
in Format_7 modes.
Note

• Build shading image always with the full horizontal
resolution

(0 x horizontal binning / 0 x horizontal sub-sampling),
but with the desired vertical binning/sub-sampling/
mirror.
• Shading correction in F7 mode 0 (Mono8) is only
available up to S400.