function corrects non-uniformity (for example, shading) in the light generated by the lens and lighting equipment. This function makes corrections when the top, bottom, and left areas do not have proper shading and are not symmetrical in relation to the center of the screen (horizontal and vertical).
This function is helpful when the effective image area (with width and height set to more than 128) is limited by the ROI function. In such cases, the ROI configures the correction area in the image. The block size is 256 x 256 pixels.
The number of blocks and pixels that form each block differ from an entire image when using the ROI function.
The following shading correction modes are available on the camera:
FlatShading
(monochrome and color models): Correction is performed using the area of the screen with the highest brightness level as the reference and adjusting the brightness levels of the other areas to match this level.
ColorShading
(color models only): R-channel and B-channel properties are adjusted using the G-channel shading properties as a reference.
For
FlatShading
and
ColorShading
, the maximum correction gain for all pixels equals eight times the gain before correction. If the area in the screen with the highest brightness level is 175 LSB or less (during 10-bit video output), proper correction is not possible.
When using the
ShadingCorrection
function, configure the settings as outlined in the following table:
Item
Setting Value
Description
ShadingCorrectionMode
FlatShading, ColorShading
Select the shading correction mode.
ShadingMode
User1, User2, User 3, Off
Select the user area to save the shading correction value to.
To display a white chart under a uniform light, execute the
PerformShadingCalibration
function.
After executing the
ShadingCorrection
function, the shading correction value is automatically saved to the user area selected in
