Ricoh A-C2 - Image Processing Steps and Related Sp Modes; Text Mode

IMAGE PROCESSING 26 January, 2001
6-22
6.5.7 IMAGE PROCESSING STEPS AND RELATED SP MODES
Text Mode
The text mode achieves a quality reproduction of text and sharp lines and ignores
background texture. Processing is conducted with a high resolution MTF filter;
special processing with the γ coefficient prevents background reproduction and
achieves the best reproduction of images with error diffusion. Because the Soft and
Normal settings use a weak MTF filter, the quality of the image is improved with the
elimination of moiré. The Sharp selection uses an MTF filter stronger than that of
the Normal setting, thus increasing the sharpness of lines.
Image Processing Flow Related SP Modes
Scanner Image
Correction
Shading Correction
!
Pre-Entry
Processing
Background Erase SP4-903-65 (Background Erase Level)
!
Smoothing SP4-903-10 (Pre-Filter Coefficient 25%~64%)
SP4-903-11 (Pre-Filter Coefficient 65%~154%)
!
Magnification Main Scan Direction SP2-909-01 (Main Scan Magnification)
!
Independent Dot Erase SP4-903-60 (Independent Dot Erase Level)
!
Filter Processing MTF Correction SP4-903-20~35 (MTF Filter Coefficients,
Strength)
!
Density Control
γ Coefficient
!
Grayscale
Processing
Error Diffusion