IMAGE SIGNAL SMOOTHING DEVICE AND METHOD, IMAGE ENCODING DEVICE AND METHOD AND IMAGE DECODING DEVICE AND METHOD

摘要

PROBLEM TO BE SOLVED: To reduce the deterioration of picture quality of the decoded images by performing the smoothing by means of the reciprocal of the difference value while suppressing the reduction of resolution of an entire screen. SOLUTION: In regard to a smoothing filter that is incorporated in an intra- loop filter or a post-filter, a differenciator 231 detects the difference between the remarked pixel value and the peripheral pixel value. The absolute value of the detected difference is acquired by an absolute value device 232 and added to the non-negative value (m) by an adder 233. The inverse numbers of these added value are acquired by a reciprocal number device 234 and used as the weight coefficients. The weight coefficient are multiplied by the peripheral pixel value by a multiplier 235, and a sum total device 236 sums up these multiplication value. The weight coefficients are summed up by a sum total device 237, and the pixel value is divided by the sum total of the device 237 and smoothed. In such a way, the smoothing is performed by the reciprocal of the difference value.