Controlling The Image Memory(Ir105); Reader Unit Input Image Processing; Output Image Processing(Ir105) - Canon ImageRunner iR8500 Series Service Manual

4.5.6 Controlling the Image Memory(iR105)

iR105
The binary image data is controlled in image memory as follows:
Compression/Expansion, Rotation, and Enlargement/Reduction
Binary images are processed for compression/expansion (for electronic sorting), rotation, or resolution conversion.
SDRAM
The image data is temporarily stored as part of image memory control.

4.5.7 Reader Unit Input Image Processing

iR105i/iR105+ / iR9070 / iR8070
The image data colleted by the contact image sensor is processed by the main controller PCB.

4.5.8 Output Image Processing(iR105)

iR105
The output image data sent to the printer unit is processed as follows:
Smoothing
a. Read Image Output
In the case of text/print photo mode, the 600 x 600-dpi input images are subjected to smoothing for conversion into 1200-equivalent x 600dpi images.
In smoothing, the image data is compared to several hundred templates of 7 x 7-pixel matrices for replacing of pixels in question.
Notch processing is also performed in this block, as a pattern unique to read images.
b. Printer (PDL) Image Output
Smoothing most suited to PDL is performed, converting 300 x 300-dpi or 600 x 600-dpi data into 2400-equivalent x 600-dpi data.
Thickening (PDL output only)
If selected using a printer driver, thickening is performed to thicken fine lines for better reproduction.
PDL output images are thickened by adding 1/2 pixels (1200 dpi) to the top of a horizontal line or 1/2 pixels (1200 dpi) to the right of a vertical line.
Binary-Binary Conversion (read image output only)
Binary-binary density conversion is used as an auxiliary means to correct density during copying operation.
Reader unit
Enlargement/reduction
Edge emphasis
-intensify-to-density conversion
-density adjustment (F adjustment)
-gamma correction
Text mode
Text/photo/film photo mode
Binary processing (error diffusion)
To compression/expansion/editing block
F-4-21
Main controller PCB
Film photo mode
Binary processing (screen processing)
Chapter 4
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