Ipu (Image Processing Unit) - Ricoh D009 Service Manual

6.5.4 IPU (IMAGE PROCESSING UNIT)

Overview
The image data from the SBU goes to the IPU (Image Processing Unit) IC on the BICU
board, which carries out the following processes on the image data:
1. Auto shading
2. Filtering (MTF and smoothing)
3. Magnification
γ correction
4.
5. Grayscale processing
6. Binary picture processing
7. Error diffusion
8. Dithering
9. Video path control
10. Test pattern generation
The image data then goes to the HDD.
6.5.5 IMAGE PROCESSING MODES
The user can select one of the following modes with the User Tools screen: Text, Text/Photo,
Photo, Pale, Generation. Some of these modes have a range of different settings (e.g. etc).
To display this screen, press User Tools/Counter> Copier/Document Server Settings>
General Features> Original Photo Type Quality.
Mode
Text/Photo Glossy Photo/ Printed Photo/ Copied Photo
Photo Glossy Photo/ Printed Photo/ Copied Photo
6.5.6 SUMMARY OF IMAGE PROCESSING FUNCTIONS
Shading correction: Compensates for the possible differences in the amount of light at the
edges and center of a scanned image caused by the scanner lens, or scatter among pixels
of the CCD.
Pre-Filter Background erase: Attempts to eliminate the heavy background texture from
copies (newspaper print or documents printed on coarse paper). Elements below the
selected threshold level are eliminated.
SM
Function
6-19
Image Processing
D009/D011/D012/D013