| 摘要 |
PURPOSE:To obtain large compressibility in a natural picture by outputting an index value to show a sample value as a transmission value when there is the large change of a picture signal. CONSTITUTION:The title device has a means 5 to calculate the difference value between an initial data Si of an input picture sample signal string and a sample signal following that, a means (ROM) 7 to generate an evaluation function value Rk and comparator 8 to successively compare the absolute value of the difference value with the evaluation function value Rk and select and output an index value (k) applying to the evaluation function value Rk when the difference is smaller than a threshold set beforehand. By the output of the comparator 8, the initial data of the picture signal is replaced with Si+n=Si+Rk. Thus, a monotonous decrease function to change abruptly can be selected to the signal to change abruptly and the large compressibility can be obtained. |
