Patent ID: 7676102

Claim:
An image compression apparatus that performs lossless compression of 3D image data, comprising: an image dividing section that divides the 3D image data into a plurality of units of data, the 3D image data being composed of a plurality of frames which are respectively images of cross sections at an interval of a predetermined distance, each of the plurality of units having N blocks with N being an integer, the N blocks being respectively located at the same positions in N frames among the plurality of frames; a pixel selection section that sequentially selects a pixel in one of the plurality of units as a target pixel in a predetermined order and selects pixels located within a predetermined range near the target pixel as reference pixels; a prediction error calculation section that calculates a prediction value of a target pixel value which is a pixel value of the target pixel, according to the pixel values of the reference pixels and calculates a prediction error which is a difference between the prediction value and the target pixel value; and an entropy coding section that performs entropy coding of the prediction error in each of the plurality of units.