Gamma; Shading Correction - IAI SP-20000C-USB User Manual

8.4

Gamma

This command is used to set gamma between gamma 0.45 and gamma 1.0(OFF).
16 steps are provided. The gamma value is an approximate value.
8.5

Shading Correction

This function compensates for shading (non-uniformity) caused by the lens or the light source used.
This compensation can be performed even if shading issues are not symmetrical in horizontal and/or
vertical directions.
There are two methods of correction.
Flat shading correction:
The method to compensate the shading is to measure the highest luminance level in the image
and use that data as the reference. Luminance levels of other areas are then adjusted so that
the level of the entire area is equal. Compensation is performed using a grid of 20 blocks (H) x
15 blocks (V). Each block has 256 pixels x 256 pixels. The complementary process is applied to
produce the compensation data with less error.
Adjustable range
Less 30%
SP-20000M-USB / SP-20000C-USB
Fig.43 Concept drawing of Flat shadingcorrection
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Fig.42 Gamma correction