Patent ID: 7106900

Claim:
A method for generating a block-based image histogram using color information and brightness information of image data, comprising: grouping a plurality of pixels of the image into a block; dividing the block into four sub-blocks by dividing the block by half with respect to a horizontal direction and dividing the block by half with respect to a vertical direction and then obtaining brightness representative values of the sub-blocks and determining if an edge exists in the block and an edge type by comparing a brightness difference between the adjacent sub-blocks with a threshold; increasing related edge histogram bins on the basis of the edge type and thereby updating the edge histograms; obtaining a hue and a saturation from a color space of the image and obtaining a linear weight between representative colors of saturated colors and a linear weight between saturated color and unsaturated color using the hue and the saturation; and calculating an increase of color histogram bins with the linear weight and updating related color histograms when the color of the block is a pure color or calculating an increase of color histogram bins and brightness histogram bins with the linear weights and updating related color histograms and related brightness histograms when the color of the block is a dark unsaturated color.