Patent ID: 8229234

Claim:
A coding device, comprising: an initial resolution coding unit for coding an initial resolution image sub-sampled from an image at every interval of predetermined pixels; and a high resolution coding unit for coding images at sub-sampling intervals sequentially halved, wherein said high resolution coding unit comprises: a first adjacent pixel extracting unit for extracting adjacent four pixels already coded in previous resolution; a first pixel extracting unit for extracting the pixel being positioned at a center of the adjacent four pixels already coded in the previous resolution as a first pixel; a second pixel extracting unit for extracting the not-yet-coded pixel being positioned in a left side of said first pixel as a second pixel; a second adjacent pixel extracting unit for extracting the adjacent four pixels already coded that are positioned in an upper, lower, left, and right sides of said second pixel; a third pixel extracting unit for extracting the not-yet-coded pixel being positioned in an upper side of said first pixel as a third pixel; a third adjacent pixel extracting unit for extracting the adjacent four pixels already coded that are positioned in an upper, lower, left, and right sides of said third pixel; a pixel value predicting unit for, out of the pixels that should be coded in present resolution, predicting a value of said first pixel from the adjacent four pixels already coded in the previous resolution, which have been extracted by said first adjacent pixel extracting unit, with a linear interpolation, and predicting a value of said second pixel and a value of said third pixel from the already-coded adjacent four pixels extracted by said second adjacent pixel extracting unit and the already-coded adjacent four pixels extracted by said third adjacent pixel extracting unit, respectively, with the linear interpolation after said first pixel is coded; a prediction error calculating unit for obtaining a residual between the pixel value of the to-be-coded pixel and the predicted value; and a variable length coding unit for coding the residual.