CHAPTER 2
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COPYRIGHT © 1999 CANON INC. CANOSCAN FB330/FB630 SERIES REV.0 OCT. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Calibration is performed when CanoScan FB630U/FB636U has received calibration
command from the host computer. Calibration is to compose black shading data and white
shading data by reading and averaging the black mark and white mark on the back of the
document glass as color references for the proper color reading.
1) Black shading data composition
Black shading data is composed by reading and averaging total 15 lines of output from the
scanning unit with the LED turned OFF.
2) White shading data composition
White shading data is composed by reading 9 lines of each red, green and blue of the white
mark, and averaging the highest 5 lines of output.