| 摘要 |
PURPOSE:To attain automatic detection of a color defect of a color video signal and to make it quantitative by checking the color frequency distribution around color defect, classifying it into color stain and uneven color and calculating the color contrast between the color defect and its surrounding. CONSTITUTION:An R-Y picture 16 and a B-Y picture 17 are subject to 2-dimension differentiation and if a color defect 11 exists, a coloredge 12 is caused. Differentiated pictures are summed and the result is subject to binarization, and a retrieval window 15 is set around the gravity center 14 of the color edge 13 and the color frequency distribution 18 is formed as to picture elements in the window. Number of picture elements (frequency) TA is calculated in the range of + or -N, + or -M around the average color and in case of TA>T (reference value), it is regarded as a color stain and in case of TA<T, it is considered to be uneven color. In case of the color stain, the color contrast between the color stain and the background and the area ratio of the color stain and the noise as the result of color extraction are discriminated in combination, and in case of uneven color, the color contrast of the uneven color and number of picture elements of the uneven color are discriminated in combination. |
