| 摘要 |
PURPOSE:To prevent the compression efficiency of an image from being lowered and to improve the transmission efficiency of image data, by dividing the image into one or plural blocks, compressing the image at every block, and framing and transmitting each line of compressed data at every image element obtained by dividing by an integer value M corresponding to the grade of a transmission path. CONSTITUTION:A picture consisting of (aXb) image elements is divided by a fixed divider N in a vertical direction, and separates it to N blocks. The one-dimensional predictive encoding of data in a first line is applied at every block, and two-dimensional encoding is applied on the other lines. Where, the data amount of one transmission frame is decided by dividing each line by the divider M corresponding to the grade of the transmission path. When the M is set at 1 which shows the best grade, the data of (b) image elements of one line are transmitted in one frame comprehensively. When the M is set at >=2, b/M image elements of a remarked line are made into a frame, and (b) image element data of the remarked line are sent by sending the above frame for M times. Therefore, it is possible to perform data transmission corresponding to the grade of the transmission path as keeping the compressibility of the image element fixed. |
