| 摘要 |
PURPOSE: To improve the resolution of a digital signal by increasing the number of digits in a coefficient lower than a prescribed threshold value for the number of digits to be set among plural coefficients expressing an AC component before rounding its value. CONSTITUTION: Plural blocks having the converted value of a luminance signal such as 8×8 pixels or 2×4×8 pixels, for example, reach a memory circuit 1 as nine digits of binary data words having additional polarity bits and totally, 64 coefficients are stored. At a maximum identification circuit 2, the maximum value of a coefficient having the AC component as contents among 64 coefficients is found, temporary stored 7, delayed 8 and inputted to an address input side 3 of a memory 4 and a divider for increasing a small coefficient is formed. Afterwards, all the blocks are delayed 8' and inputted 5 as nine digits of binary words. From the ROM 4, eight digits of data words and polarity bits quantized by much higher resolution are outputted. Thus, the resolution of the digital signal is improved. |
