Mitsubishi Electric KD Series, User Manual

Page: 79 / 118

© Mitsubishi Electric Corporation
5-2-14 White correction
[Funcion]
This function is to correct variation of output from sensor IC
pixel by pixel caused by variation of illumination strength
and Pixel sensitivities . It makes all output of pixels uniform.
Refer chapter 2-3. , “how to use CIS” .
There are two types of procedures to generate White correction data as
follows.
1) Normal Trigger mode: WhiteCorrectionExecute
White correction data generation sequence is started up by executing
“WhiteCorrection Execute”. The White correction data (average of 32 lines of
pixel data) is save on the product.
2)
External Trigger mode: WhiteCorrectionExtraTriger
White correction data generation sequence is started up by providing a start
command at “WhiteCorrectionExtraTrigger”. The White correction data
(maximum values of the average of 32 lines of pixel data until the end
command is provided to CIS) are saved on this product.
“WhiteTarget_R,G,B” is a register to set a target value of the output of after
White Correction when CIS scans a white chart. The target value is based on
12 bit depths.
[Remark]
1) At factory setting, CIS has an initial white correction data for only 600dpi .
2) To prepare new White correction data , start to send command after
turning on dark correction function under scanning white reference object
having uniform reflection ratio .
3) Scanning Image has some unusual strips possibility by using incorrect
white correction data caused by scanning scratches , dirt and dusts on
white reference object when re-generate white correction data .
4) This product has memory for saving correction data every resolution as
same as dark correction. The white correction data which is applied for
CIS is automatically changed when resolution is changed.
79
Address Register name R/W Parameter
Data
Function Initial
7070h WhiteCorrectionEnable R/W 0 or 1
Set white Correction On/Off
0:OFF /1:ON
0
7074h WhiteTarget_R R/W 0 to 4095 Set red color's White Correction Target value 4000
7078h WhiteTarget_G R/W 0 to 4095 Set green color's White Correction Target value 4000
707Ch WhiteTarget_B R/W 0 to 4095 Set blue color's White Correction Target value 4000
7080h WhiteCorrectionExecute R/W 1 Generate White Correction data (Normal Trigger mode) -
7084h WhiteCorrectionExtraTriger R/W 0 or 1
Generate White Correction data (External Trigger mode)
0:END / 1:START
0
※
When operating Dark/White correction, input external sync. signal continuously, or conduct with internal sync. mode.
※
Turn on the Dark Correction for carrying out the White Correction.
White target
pixel
C
IS
o
u
tp
u
t
data output after White correction data output after White correction
Image data when scanning white reference Object Image data when scanning white reference Object
Pixel
C
IS
o
u
tp
u
t
DVp0(n): output of n-th Pixel
5-2 Setting
⑫
: White Correction
TM-XJ959A
data output after White correction