Patent ID: 6389162
Filing Date: 2002-05-14
Classification: G06K,G06T,H04N

Abstract:
An image processing apparatus comprising:input means for inputting multi-level image data representing an image; extracting means for extracting binary image data from the multi-level image data; dividing means for dividing the image into a plurality of blocks based on the binary image data; deciding means for deciding a number of quantization levels to be utilized for quantization processing for each of the plurality of blocks based on the binary image data; and quantizing means for quantizing the multi-level image data in each of said blocks by using the number of quantization levels decided by the deciding means, said quantizing means comprising forming means for forming frequency histograms of said multi-level image data in units of said blocks, wherein the number of quantization levels is determined on the basis of the frequency histograms, wherein the multi-level image data is constituted by a plurality of color component data, and wherein said binary image data is extracted by the extracting means on the basis of a distribution of said multi-level image data, said distribution being examined on the basis of the frequency histograms of said multi-level image data.