Mitsubishi Electric KD Series User Manual page 28

2-3 Definition
【 White correction 】
Original data of white output
scanning white chart
DVEp0(n) : n th pixel output
Pixel
DVEp0(n) = DVp0(n) –DVd0(n)
DVEp(n)
DVp'(n) =
DVEp0(n)
Corrected data scanning reference
white chart
Pixel
TM-XG537C
【 CIS output and signal processing function 】
2. White correction
CIS output corrected with Dark correction is the variation
in the impact of the sensitivity of the CMOS sensor, the
imaging efficiency of the lens and the illuminations intensity.
By correcting the variations using this function, read a
document having a uniform reflectivity the uniform output
will be obtained.
White correction is a procedure to correct the variation of
the output on each pixel when scanning an uniform
reflectance object or chart.
White correction corrects the white output (DVEp (n))
when scanning an object by using the white correction data
(DVEp0(n)) stored when scanning another object having an
× Target value
uniform reflectance according to the following formula.
So, CIS output corrected by White correction, DVp'(n) is
Target value
Target value can be set by register value.
There are several methods to create White correction data.
Refer to Function specification for further detailed
information.
COPYRIGHT © 2020 MITSUBISHI ELECTRIC CORPORATION. ALL RIGHTS RESERVED.
DVEp(n)
DVp'(n) = × Target value
DVEp0(n)
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