| 摘要 |
PURPOSE: To encode an information block in high quality by making an adjusting circuit to be provided with a quality circuit that decides an average quality of an information block and a modifying circuit which supplies a modi fied quality by modifying the average quality. CONSTITUTION: Each image block is encoded by a real number n1 of bit as the function of a parameter q1 which represents a quality that is applied to a control input terminal 11 of an encoder 10. An adjusting circuit 17 is provided with a quality circuit 20 which supplies a value QMOY that is an inverse number of a quality QMOY, an arithmetic circuit 22 which generates d1 that is a number of necessary bits to encode the block with the quality QMOY to each image block, an accumulating circuit 24 which accumulates difference (n1 -d1 ) that is brought about by a subtracting circuit 25, a filling circuit 26 which supplies a filling value E1 that represents the ratio between the accumulated difference and a residual amount and a modifying circuit 28 which generates a quality value that is modified by modifying an average quality as the function of the filling amount. Thereby, an image block is encoded with a sufficient quality. |
