DE-EMPHASIS FILTER WITH INTEGRATED ACHROMATIC VALUE DETECTION

摘要

The present invention relates to a digital de-emphasis filter for a SECAM-decoder for converting an input image data sequence into filtered image data, the filtered image data storing at least an auxiliary value obtained based on an input image data value. Using one recursion register 1 and the auxiliary value and the newly input image data value, one to generate a new auxiliary value and a filtered image data value to replace the contents of the circular register 1. The calculation circuits 3, 5, 7, 9, and 11 are included. In addition, in order to perform an achromatic value determination function in addition to the de-emphasis filtering, the apparatus 15 and 17 for storing and outputting the representative value of the achromatic estimation value of the SECAM signal in the filter and the outputted estimation value A first switch is provided for applying and entering the circular register 1 at the start of each burst gate period of the SECAM-signal, the computation circuits 3, 5, 7, 9, and 11 having entries The estimated value updated by the burst signal value is output based on the estimated value and the at least one burst signal value.