| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image encoding device capable of performing both encoding at a high compression rate and high quality image restoration by decoding in a short processing time. <P>SOLUTION: Compression mode determination means 3 determines a compression mode to either DPCM or PCM on the basis of target pixel data input from a terminal 21 and prediction data calculated by a predetermined method. In the case of DPCM, DPCM compression means 5 compresses a difference value between the target pixel data and the prediction data to DPCM code data having a predetermined DPCM code length. In the case of PCM, PCM compression means 7 performs compression to PCM code data having a PCM code length determined by PCM code length determination means 9. The PCM code length determination means 9 calculates a PCM code length for each piece of the target pixel data so that the total value of code lengths after encoding becomes an allowable value or lower in a unit of a predetermine pixel group among a plurality of pixels. Tag/code output means 13 attaches, to the code data, a tag indicating whether the compression mode is DPCM or PCM, and outputs them. <P>COPYRIGHT: (C)2012,JPO&INPIT |
