SU1665548A1 - Digital passband filter of chromaticity channels - Google Patents

Abstract

The invention relates to television technology and can be used in color television sets and video monitoring devices. The purpose of the invention is to reduce chroma distortion while simplifying the discrete band-pass filter. The discrete band-pass filter of the chroma signal contains non-recursive links 1, 2, 3, each of which includes a multiplier 4 per coefficient, a first delay section 5, a first arithmetic unit 6, a second delay section 7, and a second arithmetic unit 8. Amplitude-frequency response ( The frequency response of the second non-recursive link 2 is in the form of an offset cosinusoid when performing the first and second arithmetic units 6 and 8 in the form of adders. The frequency response of the first and third non-recursive links 1 and 3 are in the form of a module biased inverted cosine when performing the first and second arithmetic units 6 and 8 in the form of subtractors. The cosinusoid period is greater, the smaller the denomination of the first and second sections 5 and 7 of the delay. The amplitude of the cosinusoid is determined by the magnitude of the multiplier 4. The through frequency response is determined by the product of the frequency response of all non-recursive links 1, 2, 3. 1 Il.

Description

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but the frequency response (AFC) of the second non-recursive link 2 has the form of an offset cosinusoid when performing the first and second arithmetic units 6 and 8 in the form of adders. The frequency response of the first and third non-recursive links 1 and 3 have the ffrm of the module biased inverted cosinusoid when performing the first and second arithmetic blocks 6 and 8 in the form

subtractors. The cosinusoid period is greater, the smaller the denomination of the first and second 5 and 7 sec delays. The amplitude of the cosinusoid is determined by the magnitude of the multiplier 4. The through frequency response is determined by the product of the frequency response of all non-recursive links 1-3.1 or

The invention relates to a television technique and can be used in televisions and video monitoring devices of a color image.

i The purpose of the invention is to reduce the suit. - chroma signal while simultaneously simplifying the discrete band-pass filter.

The drawing shows a structural electrical circuit of a discrete band-pass chrominance filter.

i The discrete chrominance bandpass filter contains three non-recursive links 1-3, each of which includes a multiplier 4 by a factor, the first delay section 5, the first arithmetic 6 / joK 6, the second delay section 7 and the second arithmetic unit 8, and 1 and the third 3 non-recursive units x the first 6 and the second 8 arithmetic units 6 and 8 are made in the form of subtractors, and in the second non-recursive unit 2 the first 6 and second 8 arithmetic units are made in the form of adders.

Discrete bandpass filter chrominance signal works as follows.

The amplitude-frequency characteristic (A | ChH) of the second non-recursive link 2 has the form of an offset cosine curve when the first 6 and second 8 arithmetic blocks are executed as adders. The frequency response of the first 1 and third 3 non-recursive links are in the form of a module biased inverted cosine with the execution of the first 6 and second 8 arithmetic units in the form of subtractors. The cosine curve period is greater, the lower the nominal value of the first 5 and second 7 delay sections. The amplitude of the cosinusoid is determined by the magnitude of the coefficient K of the multiplier 4. Through

on the frequency response is determined by the product of the frequency response of all non-recursive links 1 - 3.

The discrete band-pass filter provides the transmission of the entire spectrum of the chroma signal and deep suppression of the low-frequency part of the spectrum where the luminance signal is transmitted, as well as the signal with a frequency of 6.5 MHz - the sound signal.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A discrete chrominance bandpass filter containing three non-recursive links connected in series, each consisting of a first delay section and a first arithmetic unit, and each of the first two non-recursive links also contains a second delay section and a multiplier by a factor that differs from in order to reduce the chrominance signal distortion while simplifying the discrete band-pass filter, a second arithmetic unit is inserted into each non-recursive link, and a third The clerk factor and the second delay section are entered in the recursive link, the arithmetic blocks in the first and third non-recursive links are made in the form of subtractors, and in the second non-recursive link - in the form of an adder, in each non-recursive link the multiplier per coefficient, delay section, the first arithmetic block , the second delay section and the second arithmetic unit are connected in series between the input and output of the non-recursive link, and the input and output of the multiplier by the coefficient are connected to the second inputs, respectively the first- and second arithmetic units.