| 摘要 |
PURPOSE:To realize a high compression ratio and to shorten the transmitting time, by successively giving a new signal having a value of 2<4> to each block consisting of four picture elements on each scanning line, and by encoding the address and the block value of an altered block on the block sequence. CONSTITUTION:Each small frame of the diagram represents a freshly produced block and its value. a0 indicates the starting address and a-1, a1 and b1 indicate the address of blocks indicated in the diagram. Moreover, it is determined that V1(x) and V2(x) represents reference lines, respectively, and the value y-z of a block (x) on an encoding line represents the relative address of (y) with the (z) as a reference. The encoding means is performed by the following procedure. When¦a1-b1¦<=3 and V1(a0)= V2(a0),the encoding is performed under the vertical mode and the value, a1-b1 is assigned. When the above-mentioned conditions are not satisfied, the encoding is performed in such a way that, when V1(a0)=V2(a0), the encoding is performed under the horizontal mode 1 and a code which represents the mode 1 and another code which represents a1-a0 are assigned, and, when V1(a0)not equal to V2(a0), the encoding is performed under the horizontal mode 2 and a code which represents the mode 2, a code which represents the value of V2(a0), and a code which represents a1-a0 are assigned. Then the a0 is moved to the address of a1. The above-mentioned procedure is repeated and the encoding is performed. |
