Ricoh D009, Руководство по обслуживанию

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Image Processing
SM 6-21 D009/D011/D012/D013
Det
ailed
Des
cription
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photographs and eliminate moiré by using the highest density and
γ
coefficient in the
reproduction of grayscales and dithering. Print Photo performs smoothing and dithering for
photos copied from magazines, newspapers, etc. The Normal selection uses a higher
resolution setting and employs error diffusion but does not use smoothing to improve the
appearance of text in photographs. Glossy photo paper employs MTF filter processing and
error diffusion to copy glossy or matte photographs and achieves a low incidence of moiré,
thus reproducing copies of photographs of high resolution.
For photo mode, the features used depend on which type of greyscale processing has been
selected for Photo mode (either ‘dithering and smoothing’ or ‘error diffusion and MTF’).
Pale (Low-Density Mode)
Pale achieves image quality comparable with Text mode, but of lower contrast. Pale
employs an MTF filter stronger than that employed by the Text mode and uses a darker
γ
coefficient, thus increasing the incidence of copying textured backgrounds. Ideal for copying
extremely thin originals. Soft employs an MTF filter weaker than Normal, thus achieving a
softer image with less moiré. Sharp employs an MTF filter stronger than that of Normal, thus
increasing the sharpness of lines.
Generation Copy Mode
Generation Copy, based mainly on Text mode, aims to achieve the best reproduction of
copied originals (so called “generation copies” or copies of copies). This mode 1) employs
an MTF filter weaker than that of the Text mode to eliminate spurious dots, 2) uses the
γ
coefficient to smooth the image, and 3) uses generation processing to thicken thin lines. Soft
employs an MTF filter weaker than the Normal setting to achieve a softer image with less
moiré. Sharp employs an MTF filter stronger than that for Normal to emphasize lines for
better image quality.
6.5.8 INDEPENDENT DOT ERASE
Independent dot erase (set with the SP mode settings listed in the table below) remains in
effect even when a “Custom Setting” is selected with the User Tools.
Independent dot erase targets for elimination random, irregular shaped black dots on the
surface of the original that would otherwise appear in the copy after scanning and printing.
The strength of the application of this feature can be adjusted for each mode.
The filter compares each pixel with the pixels around an area 7 pixels x 7 lines. If the sum of
the pixels at the edges is smaller than the threshold value, the object pixel is changed to
zero (white) depending on the strength of the SP mode setting. Setting a larger setting
increases the number of dots erased, but if set too high, this SP can also remove small or