IMAGE ENCODING DEVICE, AND IMAGE ENCODING METHOD

摘要

The present invention provides an image encoding device that can balance encoding at a high compression ratio and restoration of a high-quality image by decoding in a short processing time. Compression mode determination means 3 determines a compression mode to be one of DPCM and PCM based on target pixel data inputted from a terminal 21 and predicted data calculated by a predetermined method. For the DPCM, DPCM compression means 5 compresses a difference value between the target pixel data and the predicted data to DPCM encoded data having a predetermined DPCM code length. For the PCM, PCM compression means 7 compresses the target pixel data to PCM encoded data having a PCM code length determined by PCM code length determination means 9. The PCM code length determination means 9 calculates the PCM code length for each piece of target pixel data such that a total of post-encoding code lengths becomes an allowable value or less in a unit of predetermined pixel group among the plurality of pixels. Tag/code output means 13 outputs the encoded data by adding a tag indicating whether the compression mode is the DPCM or the PCM to the encoded data.