| 摘要 |
PURPOSE:To obtain multistage picture compressing which is sequentially reduced in steps by reducing an original picture at an appropriate ratio to prepare an average value picture, executing the 1st stage picture compressing, by using as a new original picture the picture compressed at the 1st stage to execute the second stage picture compression, and by continuing the same operation on the 3rd stage picture compression. CONSTITUTION:First, original picture 1a having 8X8 picture element size is divided into a plural number of blocks for each 2X2 picture elements, average value 3a is obtained for each block, and average value picture 4a is prepared by reducing the original picture at an appropriate ratio. The difference between each block of this average value picture and that of original picture is obtained to prepare difference picture 5a, while this difference value is coded to prepare coded picture 6a. Next, after taking the average value picture 4a prepared by the picture compression at the above-described 1st stage for new original picture 1b, the 2nd stage picture compression is executed in the similar manner as the 1st stage procedure. By repeating the above procedure, picture compression is executed at many steps on the original picture whose size is reduced sequentially in steps and the coded picture data is successively stored in a cumulative device. |
