APPARATUS AND METHOD FOR GENERATING TYPICAL COLORS FOR IMAGE CODING

According to one embodiment, an acquisition unit acquires a pixel block having a predetermined size from image data to be coded. A comparison unit calculates a distance between a color of a target pixel in the pixel block and each of a plurality of typical colors, and selects a typical color of which the distance is a minimum distance from the plurality of typical colors. A decision unit assigns a first index representing the selected typical color to the target pixel if the minimum distance is smaller than a first threshold, assigns a second index representing a new typical color to the target pixel if the minimum distance is larger than the first threshold, and adds the color of the target pixel as the new typical color when the second index is assigned. A coding unit codes the selected typical color, the new typical color, the first index and the second index.