Ricoh HS2P PLUS Instrukcja serwisowa - Strona 12

Przeglądaj online lub pobierz pdf Instrukcja serwisowa dla Skaner Ricoh HS2P PLUS. Ricoh HS2P PLUS 21 stron. Machine code g413

16 February 2000

IMAGE PROCESSING

Image processing path

The following image processing is for the scanner. The image processing for each

of these units is explained in separate sections.

S C U

M e m o r y

S B U

I P U

Controller

S h a d i n g

Magnification/

Dither/

White/black

γ correction

Filtering

Binary process

correction

Mirror Process

Error Diffusion

conversion

G413D500.WMF

Shading Correction

The machine scans the white plate opposite the ADF exposure glass to make a

white waveform. Shading correction prevents uneven images caused by

fluctuations in scanned data due to changes in light intensity and CCD sensitivity.

Magnification

Reduction and enlargement in the sub scan direction are done by changing the

scanner motor speed or paper transport motor speed in the ADF. However,

reduction and enlargement in the main scan direction are done by the IPU.

Mirror Processing

A mirror image of the original must be made for output.

Filtering

There are two software filters: the MTF filter and the smoothing filter. The MTF filter

emphasizes sharpness, and is used with text-only documents or documents that

contain text and photo areas. The smoothing filter is used for photo-image

documents.

Gamma ( γ γ γ γ ) Correction

The gamma curve corrects the response of the CCD to grayscales in the original.

Grayscale Processing

This process generates up to 256 image density levels for each pixel.

Dithering

Dither processing produces good quality grayscale images of photo originals.

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