Photo Mode Image Quality - Ricoh B291 Service Manual

IMAGE PROCESSING

Photo Mode Image Quality

This section describes how to select a setting to improve image quality in the Photo
mode with dithering in order to create an extremely smooth photo image.
Generally, a larger dithering matrix uses rougher dither pattern to reproduce a
smoother gray image, but lowering the resolution can make text and lines more
difficult to see. Conversely, a smaller dithering matrix uses a finer dithering pattern
to reproduce a gray image of rougher texture, but raising the resolution can make
text and lines easier to see.
SP4904 002 Quality Photo Mode
Setting Dither Pattern
0 8 x 8 (75 lines)
1 8 x 8 (106 lines)
2 6 x 6 (142 lines)
3 4 x 4 (212 lines)
For these dither adjustments to take effect, SP4904 1 (Grayscale Photo Mode)
must be set to "0" to enable dithering.
Here are some general rules:
• If your main concern is reproducing legible text, use the smaller matrixes, but
a smaller matrix could cause spurious lines to appear in images.
• When using the smallest matrix with setting "3" (4 x 4), you should switch off
the smoothing filter for the Photo mode by setting SP4903 37 to "0".
• Use the largest dither matrix (setting "0") for originals that contain dot
screening such as newspaper and magazine photographs.
B291/B295/B296/B297
CÓPIA NÃO CONTROLADA
Picture Text
Quality Quality
High Low
Highest Low
Medium Medium
Low High
6-42
CÓPIA NÃO CONTROLADA
Processing Priority
Dot screen areas
Filled areas (highest priority)
Default
Filled areas
Resolution
SM