INTERLACE SIGNAL CODING METHOD AND ITS DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an interlace signal coding method and its device that reduce deterioration in image quality caused around an edge of a moving object in a vertical direction so as to realize high image quality. SOLUTION: A horizontal direction comb-line part detection section 12 receiving an input image supplied in the unit of frames detects a comb-line part in a horizontal direction comprising mainly a vertical Nyquist frequency component to provide an output of a quantity denoting a degree of detection to a mixer 16, a vertical high pass filter 14 applies vertical high pass filtering to the input image, the mixer 16 applies subtractive mixing to a pixel value of the input image and the result of the vertical high pass filtering depending on a ratio in response to the quantity denoting the degree of detection, and a sub band division type encoder 18 applies sub band division type encoding to the result of the subtractive mixing so as to reduce a signal component causing quantization distortion and eliminates image quality deterioration caused in the vicinity of an edge of a moving object in the vertical direction without the need for modifying the existing sub band division type coding algorithm at all.