| 摘要 |
PURPOSE:To facilitate easy compensation of gradation, by using a digital filter having the total sum of coefficients set larger than ''1'' to give compensation of image resolution to a digital picture and applying a gradation compensating process to the processed picture by means of a conversion table means. CONSTITUTION:The picture signal delivered from a scanner 100 is converted into an 8-gradation digital picture signal by an A/D converter 101. Then the 8-gradation picture signal is inputted to the 1st row of a register matrix 105 of (3 rows X 3 columns), and at the same time the signals shifted successively by shift registers 103 and 104 are inputted to the 2nd and 3rd rows of the matrix 105. The output of the matrix 105 is added to a digital filter circuit 106 having the total sum of filter coefficients set larger than ''1''. The circuit 106 compensates the image resolution of a picture signal in accordance with the address given from an image resolution compensation designating device 111. Then the output of this compensation is supplied to a conversion table circuit 107 which performs conpensation of gradation. Thus the gradation is compensated by the designation of a gradation designating device 112. |
