Konica Minolta bizhub C658 Service Manual page 1915

bizhub C658/C558/C458/C368/C308/C258
11. Temporarily stores the BTC-compressed image data.
12. The stored image data is compressed in the JBIG (Joint bi-level image experts group) format.
13. Each image data of R, G, and B in the copy, print, scan, and fax mode is stored. In PS printing, multi-valued data of Y, M, C, and K is
stored.
14. The image data read from the file memory is uncompressed through a method in a reverse way of JBIG compression. At this time, image
rotating or sorting processing is conducted.
15. JBIG image data are expanded in the frame memory.
16. Each image data of R, G, and B is stored in frame memory.
17. Temporarily stores the image data output from the frame memory.
18. The image data is expanded through a method opposite to that used in the BTC compression.
19. FIFO memory is used to enlarge or reduce images in the main scanning direction. The image is enlarged by increasing the number of data
readings and reduced by decreasing the number of data readings.
20. Reduction processing is conducted in sub scanning direction. No processing is done at same size or zoom, but at reduction, the lines are
thinned out.
21. The R, G, and B data is converted to the Y, M, C, and K density data. Also, the masking processing, which compensates for the deviation
in the spectral reflection characteristics of the toner, and UCR/BP processing are performed on the image data.
22. The security pattern is embedded in the image data. Either enabling copying through a password or unconditionally prohibiting copying can
be selected from the control panel for the security pattern to be embedded. (when security kit SC-508 is mounted)
23. Edge of letter and lineal drawing gets area discrimination and FEET processing is conducted according to the discrimination result.
24. When FEET processing is conducted, interpolation is done so that no influence is given to continuous gradation portion.
25. Makes the necessary corrections so that the printed gradations have linear characteristics, since the image density of the input image data
is not directly proportional to that of the printed image because of the changing developing and photo conductor characteristics.
26. In photo mode during copying and PC print, the image is processed as multi-valued data (8-bit data). In any mode other than photo, the
error diffusion method is employed to process the image as binary (1-bit) data.
27. Creates the density distribution of a predetermined pattern to enable outstanding gradation reproduction.
28. For 1200 dpi writing, the 600 dpi image data is converted to corresponding 1200 dpi image data.
29. Image data of the file memory is developed to the frame memory and output delay control for the interval of photo conductors, Y, M, C, K is
conducted.
30. Correct the shear in printing start position in the main scanning direction, which occurs when each PH unit of Y, M, C, K is exposed on the
photo conductor. Adjust the processing speed in the board (main scanning) to conform to the input processing speed.
O THEORY OF OPERATION bizhub C658/C558/C458/C368/C308/C258 > 18. IMAGE
O-140
PROCESSING