Image processing function overview
The image signals from the SBU (PCB7) are subjected to various image processing, and output to the controller (memory). The image signals from the controller (memory) are received, and output to the LDB (the LDB is provided in the laser unit).
Image processing overview (copy application)
Digital signal data output from the SBU (PCB7) is subjected to shading correction and line interval correction, as well as image processing. Finally, the data is sent to the machine as digital signals-4 bit/pixels.
Image processing items | Details |
|---|---|
Shading correction | Corrects for uneven scanner lamp lighting, and scatter in CCD light receiving sensitivity. |
Line interval correction | Line shift during sub-scanning magnification/reduction by the scanner. Corrects integer part. |
Dot correction | Line shift during sub-scanning magnification/reduction by the scanner. Corrects below the decimal point. |
Vertical line correction | Corrects a vertically striped image during sheet-through ADF. |
Image area separation | Determines text parts and photo parts of the image. |
Scanner gamma correction | Corrects scatter of image data relative to exposure amount. From reflectivity linear to density linear. |
Filter | Performs image sharpness adjustment and removes moire effect. |
ADS | Performs natural complexion removal in the full-color mode. |
Color compensation preprocessing | Determines hue in masking mode, and improves chromaticity. |
Color compensation | Converts RGB data to density value CMYK data of color materials. |
Image magnification change | Arbitrarily changes main scanning magnification, sub-scanning fixed image reduction and magnification of scanner image. |
Image shift function | Shifts image data in the main scanning or sub-scanning directions. |
Image binarization function | In scanner mode, outputs a binary signal. |
Image mask | Masks an area outside a frame of an arbitrary region in scanner or printer data. |
Image compression/expansion | Compresses or expands an image. |
Printer gamma correction | Adjusts exposure amount of photosensitive body relative to image density. |
Gradation processing | Applies 600dpi, 4bit 16 value gradation processing. |