SU1408542A1 - Device for extracting signal of defective zones of television image - Google Patents

Abstract

The invention can be used to monitor the quality of printed circuit boards, in the analysis of aerial photographs, etc. and ensures a higher probability of separating the signal from the defective areas with an arbitrary distribution of the image intensities. The device contains ADC 1, unit 2 centering on video signal zones (BC) and shaper 3 TV signal. A / D converter 1 converts the VS of the reference image into an N-bit binary position code. At the same time, the range of changes of the reference BC is divided into-N non-intersecting regions, each of which corresponds to logical 1 in only one particular code bit. This code controls the keys 4 of the block 2. The aircraft being processed goes to the block 2 synchronously with the arrival of the reference aircraft at ASCH1 1. The voltage taken from the resistor 6 is equal to the difference between the treated BC and the average value, respectively. the area of the reference BC that is switched respectively. key 4. As a result, the driver 3 receives a signal, respectively. areas of the processed image that are absent in the VS of the reference image. Shaper 3 converts this signal to unipolar. 2 Il. with IS tf: with

Description

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The invention relates to a television (TV) technique and can be used in production for controlling the quality of printed staff, photomasks of microcircuits according to their images, in the analysis and interpretation of aerial photographs in the national economy.

The purpose of the invention is to increase the likelihood of the signal signaling defective areas with an arbitrary distribution of image intensities.

FIG. 1 shows a structural electrical circuit of the device for extracting a signal of defective areas of a TV image; Fig. 2 shows voltage diagrams.

A device for extracting a signal of defective areas of a TV image contains (FIG. 1) an analog-to-digital converter (ADC) 1, a unit 2 centering on video signal zones and forming: 1: 3 TV signals. Block 2 contains N keys 4, N capacitors 5 and a resistor 6,

The device works as follows

A / D converter 1 converts the video signal of the reference image (FIG. 2a) into a bit binary positional code so that the entire range of changes of the reference video signal is split into n non-intersecting regions (FIG. 26). Each region corresponds to the presence of a logical 1 in one defined bit. code. This code goes to the control inputs of the N keys 4 and controls their operation. Each of the N capacitors 5 and the resistor 6 form one of the calculation branches of the signal centered on the corresponding standard of the signal, Only one of the branches is turned on at a time. The input of block 2 (Fig. 2c) is supplied with a video signal of the processed image, which is a periodic function of time. Its period is equal to the frame duration including the return time). At the input of ADC 1, the video signal of the reference image is supplied synchronously with the processed image, thereby ensuring the frequency of the input effect on the N channels of block 2.

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In this case, the voltage taken from the resistor 6 (FIG. 2g) is equal to the difference between the input signal to be processed and the average value taken over the area of the reference that is currently selected by ADC 1 and switched by key 4. Therefore, the input of the imager 3 is supplied the signal having the minimum value in the mean square sense, in this signal there are only areas of the processed image that are absent in the video signal of the reference image.

The signal is then fed to the input of the 3 TB signal generator, where it is converted into a unipolar signal (Fig. 2d), for example, by passing through a rectifier. If necessary, synchronizing pulses can be added to the signal.

When visualizing the output signal, the defective areas of the processed image looked significantly brighter than the background.

Claims (1)

Invention Formula A device for extracting a signal of defective areas of a television image, comprising an analog-to-digital converter with N outputs, the input of which is the video signal input of the reference image, and a centering unit for video signal zones, including N keys, the analog inputs of which are being processed and the video signal of the image being processed The outputs are connected to the first capacitor plates, the second plates of which are combined and connected via a resistor to a common power bus, characterized in that, for the purpose With an increased probability of separating the signal of defective areas with an arbitrary distribution of image intensities, the connection point of the second capacitor plates and a resistor is connected to the input of the input television signal generator, and the N outputs of the analog-digital converter are connected directly to the control inputs of N keys. 9us.2