Patent ID: 8699792
Filing Date: 2014-04-15
Classification: H04N

Abstract:
1. An error diffusion processing circuit comprising: an adder circuit that adds cumulative quantization error data to target pixel data of image data including a predetermined number M of color components, to generate corrected data, M being a positive integer; a quantization circuit that quantizes the corrected data by a predetermined number (P−1) of quantization thresholds to a P-valued quantized data, P being an integer of 2 or more; a quantization error calculation circuit that calculates quantization error data on the basis of the corrected data and the quantized data; a memory having a predetermined size in which a number (P−1)×M of dithering threshold matrices in a predetermined size for each of the quantization thresholds and the color components are pre-stored; and a quantization threshold selector configured to select a number (P−1) of matrices for the color component of the target pixel data from the dithering threshold matrices stored in the memory, and read an element from elements of the selected matrices in accordance with a pixel position of the target pixel data in the image data for output as the number (P−1) of quantization thresholds, wherein a data size of the dithering threshold matrices is set to be equal to or less than a value obtained by dividing a size of the memory by the number of dithering threshold matrices.