| 摘要 |
PROBLEM TO BE SOLVED: To provide an image data encoding method which can encode image data in which a basic color and a characteristic color which can reproduce an approximate color by combining the basic color at a prescribed ratio are set to be color components so that a value of the characteristic color can be restored while a sufficient decoded image and compression efficiency are secured.SOLUTION: In individual pixels, values of individual color components when a color equal to that of the pixel is shown only by basic colors are obtained. A value of the characteristic color component which becomes the maximum in the values of the respective color components when a color equal to that which the values of the color components show is shown by the basic colors and characteristic colors and in the values of the color components in which values of all the basic color components become positive or zero is obtained as S'. Data is encoded by using a replacement ratio equivalent to a ratio between S' and a value of a characteristic color component of original data and color information which is obtained by showing the color equal to that of the pixel and is constituted of a prescribed component which does not use the characteristic component. |
