CHAPTER 3 MAIN CONTROLLER3-8 COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 20012 Digital image Processing2.1 OutlineThe image memory and the digital image processing mechanisms are controlled by themain controller PCB; the following is a block diagram of the digital image processingmechanisms:F03-201-01 Block Diagram8Reader unitEditingDensity correction(LUT)Binary processing(error diffusion method; text,text/photo, print photo)Image memorycontrolBinary processing(dither screen method; film print)8Density correction(γ conversion)888Edge emphasis1Compression/expansion,rotation,enlargement/reductionSDRAMI/O control HDDImage server4 or 2Thickening4 or 21Smoothing1Binary-binary densityconversionPrinter unitPrinter PG188Main controller PCBDensity adjustment(F-value conversion)Brightness/Densityconversion (LOG conversion)Enlargement/Reduction(main scanning direction)Reader PG Image dataafter shading
