2 - 28 COPYRIGHT © 2003 CANON ELECTRONICS INC. CANON DR-6080/9080C REV.0 SEPT. 2003CHAPTER 2 FUNCTIONS & OPERATION3. Image Resolution ConversionIn this mode, the image resolutionconversion differs according to the image mode.Thinning-out is available for binary mode,smoothing is available for grayscale mode, andeither one is selectable for color mode.The resolution in the main-scanningdirection is the same as in the sub-scanningdirection.The optical resolution (main-scanningdirection) of the reading unit can be switchedbetween 600 and 300 dpi. Therefore, when 400dpi is selected, the resolution is converted from600 dpi, and when 240 dpi or less is selected, it isconverted from 300 dpi.a) Thinning-out methodFor the main-scanning direction, the imageresolution conversion is executed by thinning outthe standard clocks for image processing. (Referto Fig. 2-503)When converting to 200 dpi, the standard300 dpi clock is used, with 1 clock pulseremoved from every 3 pulses. When convertingto 240 dpi, 1 clock pulse is removed from every 5pulses. And, when converting to 400 dpi, thestandard 600 dpi clock is used with 1 clockremoved from every 3 clock pulses.1 2 3 4 5 6 7 8 9 10 111 2 3 4 5 6 7 8300 dpi standard clock300 dpi image data200 dpi operating clock200 dpi image dataFig. 2-503
