电视接收机中的数字信号处理

本文从全电视信号的频谱特征出发,讨论了各种数字梳状滤波器的分析设计。这些数字梳状滤波器,使亮度和色度信号达到了最大限度的分离,从而大大地降低了亮—色交调失真及相互串扰,提高了电视接收机的观看效果。文章在最后给出了进一步彩电观看效果的方法,如降低大面积场间闪烁和局部行间闪烁。总之,所有这些对未来视频系统的分析设计提供了不少启迪和借鉴。

Digital signal processing in TV receivers

The modern tread of replacing analog electronic circuits by digital ones is now starting to take effect in colour TV receiver. Besides bring economic advantages,digitization can substantically improve the guality of present TV picture. The improvements include a better seperation of the chrominance and luminance information,noise reduction and the reduction of large-area flicker and line flicker. New features such as "freeze-frame, combined pictures, the magnification of parts of a picture and teletext memory also appear. This article describes the back-ground and present capabilities of digital TV signal processing. Some charactoristic filter operations are discussed, including vertical filtering and temporal filtering. It is found that in very many cases there is a need for economic field or picture memories. The importance of making the right choice of sampling rate is underlined. The article is concerned mainly with the NTSC system and PAL system.