COLOR LEVEL CONTROL METHOD FOR COLOR OUTPUT OF VIDEO DECODER, AND AUTOMATIC COLOR SATURATION DEGREE CONTROLLER

摘要

PROBLEM TO BE SOLVED: To provide a method and device for controlling the color level of the color output of a video decoder by automatically comparing the measured burst amplitude value with, an ideal by means of a recursive system and then generating a color difference signal by changing the gain of color calculation. ;SOLUTION: This device consists of a comparator 70, an addition block 74, a cumulative register 76, a multiplication block 78, etc. The color difference signals U and V which are related to YUV color format are extracted. Then the actual burst amplitude of a decoded video color signal is measured and compared with the ideal burst amplitude, after a ratio (magnification) has been decided against the ideal burst amplitude by means of a recursive expression that only needs addition and subtraction. Then the nominal correction rates are decided for the U and Y color difference signals. These correction rates are multiplied by the magnification by means of the recursive expressions, showing 1st and 2nd nominal correction rates which are divided by the magnification. Then the color difference signals are multiplied by the correction rates which are multiplied by the magnification.;COPYRIGHT: (C)1999,JPO