Image processing method and apparatus using rounding processing
AssigneeCanon Kabushiki Kaisha
InventorsTadayoshi Nakayama, Hiromi Fukuda
Life of this patent
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Abstract
An image processing apparatus and method capable of suppressing noise and improving the S/N ratio of a processing output signal when a color signal representing color image data is processed. The RGB.fwdarw.YUV converter is comprised of conversion units 201-1 . . . 201-k, adder 205, and rounding processing circuit 206 which are built in the image processing apparatus such as a color printer, each of the conversion units 10 201-1 . . . 201-k is provided with an adder 11 between the multiplier 10 and rounding processing unit 12 and corrects errors generated by the rounding processing circuit 206.
Claims10
An image processing apparatus comprising:
- conversion means for performing a conversion processing on a plurality of image data, and effecting a first rounding processing on the plurality of image data;
- addition means for adding the plurality of the image data outputted from said conversion means;
- and
- process means for performing a second rounding processing on the image data outputted from said addition means, wherein
- said conversion means respectively multiplies the plurality of the image data by a predetermined coefficient, and corrects each of the multiplied image data in consideration of asymmetric rounding error data of the second rounding processing.
A method of processing a plurality of image data with at least two rounding processes comprising the steps of:
- inputting a plurality of image data;
- respectively multiplying the plurality of image data by a predetermined conversion coefficient;
- correcting each of the plurality of multiplied image data with consideration of asymmetric rounding error data of a second rounding processing;
- performing first rounding processing on each of the corrected image data;
- adding the corrected image data which is subjected to the first rounding processing step;
- performing second rounding processing on the added image data;
- and
- outputting a final result by the second rounding processing step.
Dependencies are inferred from the claim text.