Patent ID: 9183643
Filing Date: 2015-11-10
Classification: G06T

Abstract:
1. A method for coding an image, comprising: acquiring a pixel block having a predetermined size from image data to be coded; calculating a distance between a color of a target pixel in the pixel block and each of a plurality of typical colors; selecting a typical color of which the distance is a minimum distance from the plurality of typical colors; assigning a first index representing the selected typical color to the target pixel if the minimum distance is smaller than a first threshold; assigning a second index representing a new typical color to the target pixel if the minimum distance is larger than or equal to the first threshold; adding the new typical color as one of the typical colors when the second index is assigned; and coding the selected typical color, the new typical color, the first index and the second index, wherein, if adding the new typical color would cause the number of typical colors to be larger than an upper limit, not adding the new typical color as one of the typical colors and assigning the first index to the target pixel, wherein the first threshold is determined for each typical color, wherein the method further comprises: wherein the assigning includes using the first threshold differently adjusted for the each typical color.