SU1231627A1 - Forming device for correcting distortions of television picture - Google Patents

Abstract

The invention provides improved performance to accuracy. The device operates in 4 modes defined by the signal from the zero detector (DN) 9. In the 1,11,111,1Y modes, correction signals for geometric distortions of TV images (CXI) are generated in the horizontal scanning direction, in the direction of frame scanning, uneven background and irregularity of the video signal. Two test tables are used to a set of reference signals arriving about to Jl T

Description

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from generator 2 reference signals. Synchronizer 3 provides the device blocks with appropriate signals. In 1 mode, the video signal of the reference image from the video signal sensor 1 is fed through a quantizer 18 to a phase detector (PD) 17, to the reference input of which a binary-quantized signal from the quantizer 15 is fed. For generating CGGI, a set of corresponding signals is received from the orthogonal signal generator 4 block 12 multipliers and. per weight summing unit (HBC) 6. The formation of the correction signal consists in finding the optimal values of the control signals of the weight coefficients (}) by the factors of the orthogonal component signals from the memory block 7, at which the generated CGD provides the minimum PD signal 17. Initially formed SKGI

The invention relates to television and can be used in broadcast and applied television as part of television (TV) systems of automatic correction of image distortions in real time.

The aim of the invention is to increase speed and accuracy.

On fng. 1 shows the standard output circuit of the signal conditioning device for correcting the distortion of the image; figure 2 - timing diagrams.

A signal shaping device for correcting a scanned image TV image (Fig. 1) contains a video signal sensor 1, a generator of 2 reference signals, a synchronizer 3, a generator of 4 orthogonal signals, a weight signal generator 5, a weight block block b, a memory block 7 , weighing unit 8, detector 9 zero, sampling unit 10, first switch 11, multiplier unit 12, integrator unit 13, second switch 14, first quantizer 15, amplitude detector 16, phase detector 17, second quantizer 18.

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enters the video signal sensor 1 to change the current in the horizontal deflection cat aux. PD 17 selects a residual ikazyvaya signal, which through the switch 11 enters the weighing unit 8. The orthogonal components of the signal are filtered out of the weighted residual distorting signal, for which from the block 8 the weighted signal is through the multiplier block 12, the integrator block 13 and the switch 14 are fed to the DN 9 and recorded in it. Then, from DN 9 to memory block 7, a postz signal is transmitted to change the control signal weighting coefficient. Air Force b forms new SKGY, etc. The DN 9 calculates the optimal values of the control signals weight coefficient. orthogonal component signals for SKHI. In the 111 and 1Y modes, the amplitude detector 16 and the gating unit 10 operate. 2 Il.

The device operates in four modes specified by the operating mode selection signal from the first output of the detector 9 zero.

In the first mode, a signal is generated to correct geometric distortions of the TV image in the horizontal scanning direction (horizontal geometry). In this case, a reference signal is generated by the generator 2 of the reference signals (Fig. 2a), which is identical to the undistorted video signal from the optical reference image of the first test table, which is formed in the video signal sensor 1, corresponding to alternating vertical black and white stripes and contains phase and amplitude distortions geometrical distortions of the TV image in the direction of the line scan and the rhythm distortions of the TV image (FIG. 2b where ENO mismatch TV image size reference). The video signal of the reference image from the signal output of sensor 1 is fed to the input of the second quantizer 18, made on the comparator with a hysteresis, to the non-sizing input of which the video signal is fed directly, and to the inverting one - with a delay. A binary-quantized video signal of the reference image is generated at the output (Fig. 2c). In the binary-quantized video of the reference image, only information about the geometric implications of the TV image in the direction of the horizontal scanning is stored. The generator 2 is synchronized by a mixture of damping pulses arriving at its first control input from the synchronization output of sensor 1. This reference signal, in accordance with the operating mode selection signal fed to the second control input of the generator 2, is fed to the input the first quantizer 15, at the output of which forms a binary-quantized reference signal (FIG. 2d), in which information is stored only about the phase of the reference signal. The binary-quantized reference signal is fed to the reference input of the phase detector 17, to the signal input of which a binary-quantized video signal of the reference image is fed. The phase detector compares the phases of these signals and at its output a distorting signal characterizes the distribution of the geometric distortions of the TV image over the area of the raster in the direction of the horizontal scanning and is presented in the form of pulse-width modulation (FIG. 2e). To correct geometric distortions of the TV image in the line scan direction, at the output of the weight summing unit 6, a correction signal is generated, which is a weighted sum of the orthogonal component signals defined on the raster field and synchronous with the TV scan. To form it, the signal input of block B is supplied via a signal bus by a set (system) of orthogonal components from the output of the generator 4 orthogonal signals, and to the control input of block 6 are sent through the data output of memory block 7 orthogonal signal components. The control signal is a binary code whose value specifies the weight and phase (value of the high bit of the code) of the corresponding ortho

j 5 0 5 about 5 0 5

(1 of the signal to be corrected. The set of values of the control signals of the weighting coefficients of the orthogonal components of the signals determines the forms of the correction signal. Generator 4 generates a set of orthogonal components of the signals that are synchronous with the TV scan using a tabular method of representing the signals. For this purpose, These storage devices of generator 4 are recorded in binary code samples of current values for each orthogonal component of the signal at the reference points of the TV raster. These counts are read synchronously with a TV scan by applying to the synchronous clock of the generator 4 an address signal from the first output of synchronizer 3, which is synchronized by lowercase and frame by dither pulses, supplied from the synchronous sensor of video signal 1 to the control input of synchronizer 3 The output of the generator 4 generates a set of analog orthogonal components of the signals by digital-to-analog conversion of samples of these components. In addition, for each orthogonal component of the signal, two antiphase signals are generated on the phase inverters of the orthogonal signal generator. The signal generation for the correction of horizontal geometric distortions consists in finding the optimal values of the control signals for the weighting coefficients of the orthogonal components of the signals at which the correction signal is generated; Introduced into the horizontal deviations of the coil of the video signal sensor coil, it provides a minimum of the energy released at the output of the phase detector 17, a distorting signal. To do this, before the formation of the third output of the detector 9 zero, the initial values of the control signals of the weight coefficients of the orthogonal components of the signals for correction of the horizontal geometric distortions and the zero values of the control signals and the BecoBbihni coefficients of the orthogonal components for the remaining three correction signals are set. These. the control signals are written to the corresponding memory cells of block 7 by the address signal available at its input from the second output of the detector 9. Initially

0

The formed signal for correction of horizontal geometric distortions is fed to the control input of sensor 1, the output of which forms an initially corrected video signal from which a residual distorting signal is extracted at the output of phase detector 17, which characterizes the distribution of residual geometric images in the area of the spectrum in , line scan after the introduction of the originally generated horizontal geometric distortion correction signal. In TV systems of various purposes, there are different requirements for the quality of the correction of TV image distortions over the raster area. Therefore, the residual-distorting signal of horizontal geometric distortion is weighed by a non-negative weighting-i signal, which sets the required law of the distribution of the correction accuracy distorted over the raster area. For this, the residual distorting signal of horizontal geometric distortions from the output of the phase detector 17 is switched to the second input of the weighing unit 8, the nerve input of which receives the weight signal from the weight signal generator 5, by the mode selection signal supplied to the second input of the first switch II. The generator 5 forms weight synchronously with the TV scan, using the table method of presenting the signal but the analogy with the generator 4. At the same time, synchronization of its operation is synchronized with the synchronous input. In block 8, the residual distorting image of horizontal geometric distortions on the weight signal is multiplied in analog form. Since the signal for correcting the horizontal geometrical is distorted as a weighted sum of the orthogonal constituent signals generated by the generator 6, therefore, only those constituent signals are compensated for in the residual distortion signal. Therefore, the correction will be the best available and the sense of the minimum energy of the residual distorting signal in the absence of these orthogonal components of the signals in the weighted residual claim: the cue signal. B connection with this.

To evaluate the quality of the correction, it is necessary to filter the orthogonal components of the signal from the weighted basic and residual distortion signal of the horizontal geometric distortions. For this, the weighted residual distorting signal is fed from the output of block 8 to the first input of block 12 of multipliers, to the second input of which a system of reference phases of orthogonal component signals from the output of generator 4 is fed through the signal bus. Block I2 simultaneously produces

5 parallel independent analog multiplication of a weighted residual distorting signal at the reference phase of each orthogonal component signal. The multiplied signals from block 12 are fed via a signal bus to the input of a block of 13 integrators, to the setup input of which the second output of the synchronizer receives reset pulses generated at the end of the dash .5 sh, it is about a pulse with a duration approximately equal to the horizontal scanning period.

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Block 13 produces parallel independent integration of the multiplied signals of block 12 (over the entire area

0 raster) during the forward course of the frame sweep. Since the orthogonal components generated by block 4 in real time are uncorrelated with respect to each other.

5 others in the raster area, the voltage at the output k; k; the total integrator of block 13 at the end of the forward run of the frame sweep will be proportional to the value of the corresponding orthogonal component signal

in a weighted residual distorting I. i

signal. The sign of this voltage uniquely identifies the phase of the corresponding orthogonal component signal in the weighted residual distortion signal relative to the reference phase of this component signal. Thus, unit 12, together with unit 13, carries out over the area

0 raster independent parallel optimal filtering orthogonal: components of a weighted residual distort signal. Filtered, signals arrive on

5 the input of the second switch 14, to the control input of which from the third output of the synchronizer 3 is fed a control signal in the form of a binary channel

The output word, the value of which corresponds to the number of the switched filtered component signal, and varies with the beginning of the frame trailing pulse with a period equal to the horizontal scanning period. Thus, all the filtered components are switched alternately by the switch 14 from the beginning of the reverse frame sweep to the data input of the detector 9 zero, which produces alternate line-to-line at the beginning of the reverse frame sweep analog-to-digital conversion of each bi-filtered signal. Transformation codes are recorded in the memory cells of the detector 9 at the moment when the write pulses generated at the address output of the synchronizer 3 after the code change at the output input to its address input. words controlling the operation of the second switch 14.

Thus, at the beginning of a frame damping pulse, but after the expiration of a length of several lines corresponding to (equal) the number of orthogonal components, the binary memory codes of all the filtered components (p ,), corresponding to the original ce1) to the signal to correct the horizontal geometric values. The codes of these samples unambiguously determine the quality of the correction of horizontal geometric distortions and, consequently, the quality (accuracy) of the formation of the most originally generated signal dp of correcting these distortions at the initial values of the control signals of the large coefficients of the orthogonal component signals. After writing the sample codes of all the filtered orthogonal component signals, the detector 9 changes at its third output the values of all the control signals, the weight coefficients, and the orthogonal components, relative to their initial values, for the initially formed correction signal of the horizontal geometric distortions by the value of g. These modified control signals Pshsladyvayutsya - through block 7 to the control input of block 6, the output of which

5 0 5 0

s

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a modified signal dp of the corrective 1 H1 horizontal geometric distortion is generated, affecting the current of the horizontal deflection coils of sensor I. As a result, the output of sensor 1 generates a newly corrected video signal of the reference image of the first test table, which in the next scan 1 second - second frame scan period undergoes the same processing the same as the originally corrected video signal in preload 1P1 is the first frame period. After the second frame period expires, the sweeps will be recorded into the corresponding cells of the memory block of detector 9 of the sample code again filtered orthogonal signal sigtal components corresponding to the newly formed signal for correcting horizontal geometric distortions with altered signal weighting coefficients of its orthogonal component signals . In addition, the cells of the memory block of the detector 9 also recorded and stored the readings of the initial o ;, and the altered wasps. control signals for weighting coefficients of orthogogic component signals. Using this data, the detector 9 calculates the optimal values of the control signals for the weighting coefficients of the orthogonal components of the signals for the horizontal geometric distortion correction signal using the formula

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In this case, the corresponding program-. The computations are recorded in the constant i memory of the detector 9. The computed optimal values of the control signals, ulonri, are supplied as binary codes on the data bus from the third output of the detector 9 to the data input of block 7 and are written to its registers at the address that goes through the bus addresses in the form of a binary code from the second output of the detector 9 to the address input of block 7. In accordance with the on-tual values of 11 signals stored in block 7, the control signal and the coefficient of orthogonal component signals are generated at the spin-down block 6 signal for the correction of horizontal geometric

distortions. Further, in the next frame of the TV sweep, the counts PP of the filtered components of the signals for each orthogonal component of the computed value of the control signal j and its weighting factor are determined and compared in the detector 9 modules / .op / i with a threshold value of 0. If / Rope, / of all orthogonal components of the signal, the search for control signals of the weighting coefficients 4) is stopped, if this condition is not met, the search is completed. When linearly controlling the weight coefficients and the signal components for the correction, as well as for the linear input of the signal itself, for correcting the corrected video signal through the control input of the video signal 7s 1 video (off the control system), the adjustment characteristics of the device are close to ideal - neyim Therefore, the search for control signals for weight goats (1) of fidient no. 1 with orthogonal component signals ends in two periods of vertical scanning, since the computational operations performed by its detector 9 are simple and take up a maximum of several horizontal scanning periods in time. during a frame extinguishing pulse after recording samples of the filtered} component signals, when the corrected video signal is not analyzed. Found.1e optimal control signals ci opt weight coefficients 4) the component components of the orthogonal signals are finally recorded in the cells of block 7. According to their values, the horizontal geometric distortion correction signal u is finally generated at the output of block 6, which is finally entered into the horizontal deflection catalysts , eliminating these distortions with high accuracy.

After that, a similar pattern is formed to correct the geometric distortions in the direction of vertical scanning. To do this, from the first output of the detector 9 to the second control inputs of the sensor 1 and generator 2, a mode selection signal is applied, corresponding to the signal generation mode for correcting the vertical geometric distortion.

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In this case, sensor 1 expands the reference image of the second test projector of the overhead projector. Since the reference image in this case is a black and white chess field, the video image of the reference image formed by the sensor 1 contains information about geometric and strength of TV image matches. Since the horizontal geometric distortions are corrected with high accuracy by a pre-formed signal to correct horizontal geometric distortions, from the video signal-reference image of the second test table 11) 1, a distorting signal characterizing the distribution of the vertical image distortion TV of the image is separated at the output of the phase detector 17 . For this, generator 2 forms the reference signal of the second test pattern. Found on this search; signal (similarly to the horizontal-laix geometric distortion correction signal), the optimal control signals of the weighting coefficients for the orthogonal component signals of the vertical geo correction signal: -1 the static distortions are stored in the block cells 7. According to the values of these control signals, a signal is generated finally at the output of block 6 for correcting vertical geometric distortions, which is applied to the control signal — the input of sensor 1 — frame deviation coils.

After forming timelines to correct geometric distortions of the TV image, a signal is generated to correct the uneven background. This uses the reference image of the second test table and the corresponding reference signal from generator 2, as in the previous mode of operation. Since both geometric distorted TV images are priced with high accuracy by inputting the generated geometric correction signals were searched, then the reference signal of the reference image was formed at the signal output of sensor I, and only distortion of the signal is inherent: uneven background and uneven video signal. 2e). To isolate the distorting signal, characterizing the distribution of background unevenness across the image field, the first and second inputs of the amplitude detector 16 are respectively supplied to the reference signal from generator 2 (Fig. 2a) and the video signal from the reference image from sensor output 1 (Fig. 2e) the output of the amplitude detector 16 of the forg. shreds their differential signal, which is fed to the signal input of the gating unit 10, to the gating input of which a binary quantized reference signal is output from the output of the first quantizer 15 (fig, 2d). In accordance with the mode selection signal received at the control inputs of block 10 and first switch 11, block 10 gates from the difference signal a distorting signal of unevenness of the background (Fig. 2g), which is switched to the second input of block 8. Found by this distorting signal ( similarly, as for the correction signal for horizontal. geometric distortion), the optimal control signals are weights of the coefficients of the orthogonal components of the correction signal. Background irregularities are finally remembered in the cells of block 7. Based on the values of these control signals, a signal is finally formed at the output of block 6 to correct the uniformity of the background, which is fed to the control input of sensor 1 and added to the video signal.

Claims (1)

After generating a signal for correcting the background unevenness, the signal for correcting the unevenness of the video signal is broken. At the same time, in block 10, the distorting signal of the unevenness of the video signal across the bit field (Fig. 2h) is gated from the difference signal. The signal found from this distortion signal for correcting the unevenness of the video signal is stored in block 7 and is fed from the output of block 6 to the control input of sensor 1. This signal is multiplicatively introduced into the video signal. The invention can be applied to correct the mutual distortions of TV images of channels of a color transmitting camera. To do this, instead of the output of the generator 2, you must connect the signal output of the sensor 1 to the tuned channel. Invention Formula Signal shaping device for correcting television distortion - Sh M 20 25 thirty 35 40 45 50 55 The first image contains a video signal sensor whose sync output is connected to the first control input of the reference signal generator and to the control input of the synchronizer, the first output of which is connected to the sync input of the orthogonal signal generator and the weight signal generator, weight summing unit, control and signal inputs which are connected to the outputs of the memory unit and the generator of orthogonal signals, respectively, and the output to the first control input of the sensor in the signal, the weighing unit, the first the input of which is connected to the output of the weight signal generator, characterized in that, in order to improve speed and accuracy, the first and second quantizer, phase detector, amplitude detector, gating unit, first switch, multiplier unit, unit but integrators, the second switch and the zero detector, the first output of which is connected to the second control inputs of the reference signal generator and the video signal sensor, to the control inputs of the gating unit and the first switch, the output of which is via serially connected blocks the weighting, multiplier block, integrator block and the second commutator are connected to the data input of the detector zero. The second and third outputs of which are connected to the input of this memory block, and the output of the reference signal generator is connected via serially connected a slotted detector and block gating with the first information input of the first switch, through the serially connected first quantizer and phase detector with the second information input of the first switch, the output of the video signal sensor is connected to torp- input amplitude detector directly and through the second quantizer - a second input of the phase detector, the output of the first quantizer is connected with an input gating The unit's gate, gating, the second input of the multiplier unit is connected to the output of the generator of orthogonal signals, the second, third and fourth outputs of the synchronizer are connected to the installation input of the integrator unit, and the address input of the zero detector by the control input of the second switch, respectively. .