摘要 |
PROBLEM TO BE SOLVED: To reduce the cost by simplifying the circuitry of a pulse width modulation circuit. SOLUTION: The printer providing a halftone representation by forming dots comprises a halftoning section (26) for converting M bit image data into N (M>N) bit driving pulse width data, and a converting circuit (47) for comparing (46) image data with a plurality of threshold values being fed from a threshold value matrix and generating driving pulse width data depending on the comparison results. A random noise is applied to the plurality of threshold values or the image data when they are compared in order to suppress occurrence of a tone jump. The halftoning section has a means for determining the position of a driving pulse depending on the driving pulse width data of a pixel adjacent to a pixel under processing. COPYRIGHT: (C)2004,JPO
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