Patent ID: 6674488
Filing Date: 2004-01-06
Classification: H04N

Abstract:
A luminance and color difference signal separator circuit for separating a luminance signal and a color difference signal which are included in a composite color picture signal representing an image, said circuit comprising:a motion detector for detecting a motion of the image and determining a motion level of the detected motion; a line correlation detector for detecting a correlation level of lines of the image; a first filter having first filtering characteristics for extracting the color difference signal from the composite color picture signal according to the first filtering characteristics; a second filter having second filtering characteristics, different from the first filtering characteristics, for extracting the color difference signal from the composite color picture signal according to the second filtering characteristics; a first weighting circuit operative in response to the motion level determined for calculating a weighted average of the color difference signals extracted by said first and second filters; a third filter having third filtering characteristics, different from the first and second filtering characteristics, for extracting the color difference signal from the composite color picture signal according to the third characteristics; a second weighting circuit operative in response to the correlation level detected for calculating a weighted average of the color difference signals extracted by said second and third filters; a selector for selecting the weighted average calculated by said first weighting circuit if said motion detector determines that the motion level of the image is below a predetermined threshold, and selecting, if the motion level of the image exceeds the predetermined threshold, the weight average calculated by said second weighting circuit, and developing the selected weighted average as an ultimate color difference signal; and a subtracter for subtracting the ultimate color difference signal from the composite color picture signal to produce an ultimate luminance signal.