Patent ID: 7728910

Claim:
A YC separation device for separating a composite signal into a luma signal and a chroma signal, comprising: a low-pass filter, for separating the composite signal into a low-frequency composite signal and a high-frequency composite signal, the low-frequency composite signal being a low-frequency luma signal; and a comb filter, for separating the high-frequency composite signal into a high-frequency luma signal and the chroma signal, the luma signal comprising the low-frequency luma signal and the high-frequency luma signal, wherein the comb filter comprises: a vertical similarity detector set, for calculating differences between the value of a predetermined point in a predetermined row and the values of corresponding points in a plurality of adjacent rows which are adjacent to the predetermined row, thereby obtaining a plurality of vertical difference values; a horizontal similarity detector, for calculating the differences between the value of the predetermined point and the values of a plurality of adjacent points in the same row as the predetermined point, thereby obtaining a horizontal difference value; a vertical comb filter set, for calculating a plurality of vertical high-frequency luma signals, based upon the value of the predetermined point in the predetermined row and the values of corresponding points in a plurality of adjacent rows, which are adjacent to the predetermined row; a horizontal comb filter, for calculating a horizontal high-frequency luma signal, based upon the value of the predetermined point and the values of a plurality of adjacent points in the same row as the predetermined point; a comparator, for determining a minimum difference value, based upon the vertical difference values and the horizontal difference value, and thus obtaining a corresponding high frequency luma signal from the vertical high-frequency luma signals and the horizontal high-frequency luma signal based upon the minimum difference value; an oblique similarity detector, for calculating the differences between the value of the predetermined point in the predetermined row and the values of adjacent points in a plurality of adjacent rows which are adjacent to the predetermined row, wherein the adjacent points are oblique with respect to the predetermined point being a centre, thereby obtaining a plurality of oblique difference values; and an oblique comb filter, for calculating an oblique high-frequency luma signal, based upon the value of the predetermined point in the predetermined row and the values of adjacent points in a plurality of adjacent rows adjacent to the predetermined row, and a minimum oblique difference value among the oblique difference values; and one of the corresponding high-frequency luma signal and the oblique high-frequency luma signal selected as the high-frequency luma signal.