SU1406821A1 - Device for noise suppression in digital television signal - Google Patents

Abstract

The invention relates to television (TV). The purpose of the invention is to simplify the device. The device contains an i-reading unit 1, a multiplier 2, an adder 3, a delay unit 4 for one frame, a limiter 5 with an adjustable level of limitation, a low frequency filter 6 with a controlled cut-off frequency, a forming unit 7 coefficients. recursion unit, gating unit 8 and accumulator 9. Subtraction unit 1 calculates the difference between the input digital N-bit TV signal and the output signal of the device of the previous frame from the output of delay unit 4, and also calculates the sign of this difference. Then multiplier 2 multiplies the resulting difference by the corresponding coefficients. recursion obtained using limiter 5, filter 6, block 7, gating block 8 and accumulator 9, Next, the supervisor 3 completes the process of recursive digital filtering by summing the value of the difference signal taking into account its sign with the output signal of the previous frame. 1 il. & maaa 1 "sh.

Description

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The invention relates to television technology and can be used to improve the quality of a television signal in hardware-test television complexes.

The circuit of the invention is a simplification of the device.

The drawing shows a structural electrical circuit of a noise cancellation device in a digital television signal.

The noise reduction device in a digital television signal contains a subtraction unit 1, a multiplier 2, an adder 3, a delay unit 4 for one frame, a limiter 5 with an adjustable limitation level, a low I filter 6 with a controllable cut-off frequency, a coefficient generation unit 7; recursion, gating and block 8; collector 9.

; A noise reduction device in a digital television signal operates i as follows.

. The digital N-bit TV I signal X (CT), determined at the time points of the CT, is fed to the input I of block 1. On. the second input of block 1 by I is the output of the device I of the previous frame Y (KT-T) from the output of block 4, which was determined at the time of CT. Block 1 calculates the difference X (CT) - USCT-T) I having the width N, and the sign I carry.

I Multiplier 2 produces a multiplication of the signal 1x (CT) - (CT-Tk) 1 by the corresponding cutting factors R (KT).

Adder 3, the summation completes the process of recursive digital filtering, summing the values of | x (CT) - - Y (KT-Tj () | taking into account the sign with the signal Y (KT-T).

The value of the signals of the interframe differences | x (CT) - Y (CT-Tk) | no sign is used in the detector. The movement formed by limiter 5, filter 6 and block 7 is

elementwise formation of recursion coefficients R (KT).

Level Limitations and

 low pass filtering is set depending on the level of noise in the input television signal. The noise level is estimated by integrating the absolute values of the scientific research institute of interframe differences without taking into account the sign in the accumulator 9 over all elements of the television raster, except for those parts where movement occurs. These areas of the raster are excluded.

5 by block 8, which is controlled by the output of block 7.

Claims (1)

Invention Formula 0 A noise reduction device in a digital television signal, containing its connected in series subtraction unit, whose input is the device input, multiplier, cyi-iMaTop and one frame delay unit, the output of which is the device output and is connected to another input of the subtraction unit connected in series limiter 0 with an adjustable limiting level, a low-pass filter with a controllable cut-off frequency and a recursion coefficient form block, the output of which is connected to another multiplier input, a gating unit connected in series, a KcjToporo reference input connected to the recursion coefficient formation block output, and a drive whose output is connected to the control inputs of the low-pass filter with a controlled cut-off frequency and a limiter with an adjustable level of limitation, characterized in that 5 simplify the device block output delays for one frame are connected to another input of the adder, and the input of the limiter with an adjustable level of restriction and the input of the gating unit are connected to the outputs of the subtraction unit. five