| 摘要 |
PURPOSE: An adaptive noise reduction filter is provided to effectively remove noise in response to luminance change without additional line memory. CONSTITUTION: An adaptive noise reduction filter includes a multiplying and adding portion(231) multiplying first, second and third vertical luminance signals of a row matrix type and first, second and third multiplying coefficients of a column matrix type, adding the multiplied values, and outputting the resulted values, a filtering signal outputting portion(233) dividing the output signal of the multiplying and adding portion by the resulted values and outputting a finally filtered signal obtained by multiplying the resulted values and a predetermined compensating coefficient, a subtracter(235) subtracting the finally filtered signal from a horizontal luminance signal, an absolute value outputting portion(237) calculating a delta value which is an absolute value of the output signal of the subtracter, a comparator(238) comparing the delta value with a comparing threshold value and generating a multiplexing control signal having different logic values for each case where the delta value is greater or smaller than the comparing threshold value, and a multiplexer(239) selectively outputting the finally filtered signal or the horizontal luminance signal in response to the multiplexing control signal.
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