摘要 |
When pixel signals included in pixel blocks forming an image are supplied, a detector detects the difference between pixel signal levels in the vicinity of block boundary of the pixel blocks. Then, a comparator compares the difference with a threshold value. An adder adds additional values to the pixel signal levels in the vicinity of block boundary in accordance with the comparison results. A pseudo random number is generated, to select a value pattern including the additional values from additional value patterns based on the random number. The above-described process can disturb the regularity of differentials in the pixel block boundary, thus positively facilitating to eliminate block deformation possibly arising in between pixel blocks.
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