SU1142905A1 - Process for reproducing television signal with interlaged decomposition - Google Patents

Abstract

METHOD OF BROADCASTING OF A TELEVISION SIGNAL WITH EXTREME DECOMPOSITION, based on a single-time bouncer of each field of a television signal, h - a short line-by-line reproduction of the stored fields of the ekaane, where T is 2,3, 4,. .., while scanning the screen horizontally occurs at a rate of -n times, and vertically n / 2 times greater than the interlaced decomposition of the original television signal, which is different. By the fact that, in order to simplify the implementation of the method, with each repeated line by line playback, the television signal of each once-stored field is successively reduced in amplitude, and decrease. Ampl 1tudi produced by the formula. X, .e (:). P-OVc, where k {is the attenuation coefficient; LjCti - dependence of effective brightness on time; c is the playback period of the fields.

Description

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 ABOUT

The invention relates to a reproduction technique of a TV (TV) signal when using TV VEP standards (Ann based on interlaced scanning, in which: k.a; kd TV signal frame is formed from two: x fields with four and odd lines of the frame. A reproduction method is known TV signal with interlaced decomposition based on the fact that a standard local conversion is performed before playback in order to switch from interlaced to progressive or higher frequency fields with interlaced However, when reproducing a mobile TV image, distortions are associated with the imposition of consecutive motion phases, which lead to unnecessary c: arousal of the TV subformance TV image:: Enry or even splitting of two existing objects. This consists of the fact that the previous field containing one phase of two-sh: 5 is reproduced simultaneously with the field containing the other phase of the movement. The closest to the proposed technical essence is the TV signal - :: stanie, based on a one-time memorization of each TV signal field, multiply line-by-line playback of the stored fields on the screen, where, 3.4, .., 5, while scanning the screen horizontally n times, and vertically n / 2 times greater than with interlaced decomposition of the original TV signal 2. However, in the known method for reproducing the TV signal of the mobile) image, adaptive interpolation of the line signals of an artificial interlaced image is used ;;;; to obtain the signals of the lines of the new progressive image. Interpolation mode varies depending on the presence or absence of motion in the original image. The availability of dvigsen1g is indicated by a dB1-hsni detector, which selects the signals of two consecutive frames and compares the differences with the set-threshold. This method is difficult to implement. . The purpose of the invention is to simplify the implementation of the method. This goal is achieved by the fact that, according to the method of playing a TV signal with interlaced-break, based on a one-time remembering ;; e-field of a TV signal, -fold line-by-line playback of the stored fields on the screen, where, 3, 4, -. screen but horizontally carried out at a speed of n times, and vertically. and in n / 2 times greater than with interlaced decomposition of the original TV signal, with Ka; iv; oM repeated line by line playback of the TV signal from the once stored field is successively reduced by aMnjni- tudu, and the amplitude reduction is produced in a form-ul k 1 -L, (t:) r (i-1) V., Where k is the attenuation coefficient; ) - dependence of effective brightness on time; Vc, is the playback period of the fields. . FIG. Figure 1 shows portions of vertical-temporal sections of a TV image that illustrate the transition from the original interlaced standard (for example, 625 lines / 25 fields, to line st1: darta. In this section, the lines of the original standard are marked with a circle, and the lines are repeated during the field conversion by dots ; the period of fields of the original interlaced standard is indicated by V); in fig. 2 - impulse characteristics corresponding to the two considered. examples of the transition from interlaced to non-interlaced; in fig. 3 - impulse response of the conversion standard for two cases of transition from interlaced to non-interlaced scanning according to the proposed method; in fig. 4 is a structural electrical circuit of the TV image reproducing device. The B-mode of reproducing a TV signal with interlace decomposition is based on the fact that in order to eliminate image flickering, it is enough to renew the past field only to a degree. in which it is forgotten by the viewer as a result of the exponential impulse response of the vision. For this, the impulse response of the sweep conversion is changed so that all peak values of the resulting characteristics are

same level. This, respectively, reduces the a-lengths of the successive but time components of the impulse response of the sweep conversion.

The transition from interlaced to non-interlaced in the vertically-time image section (Fig. 1) shows that in each field of the reproduced non-interlaced image (i.e., on the vertical lines) there are lines of the FIELD interlaced image and ( marked with circles) and lines of interrupted interlaced image ;;: e: -:; -: (marked with a dot, kami), you get: -1e by repeating the lines of the previous half of the floor.

Converting an interlaced image of 625 lines / 25 frames to a line by line with double the frequency of full frames of 625 lines / 50 frames (Fig. 1a) and with the account frequency of full frames of 625 lines / 100 frames (Fig. 1b) OS | T 1 resumes with the repetition of fields so what happens is a time alignment of pairs of consecutive fields of the original standard. In the first case, for example, the floor, Sit4e, is combined. In the presence of a motion signal in a TV, such an alignment of the skin leads to smearing, or splitting of the TV image. The occurrence of the processes is explained using the impulse response of the standard conversion (Fig. 2a, b), which are sums of delta functions shifted in time and the field repetition process (or, more precisely, each line, given to the field) and ebuem number of times.

As is well known, and; -tulse characteristic of vision, i.e. the dependence of the attenuation of visual impression on time, called in the special literature the dependence of effective luminance on time, and}, has an approximately exponential nature (Fig. 2c) with a constant time of about ten milliseconds.

As a result of the joint action of converting the standards of sweep and vision, the sh-shulnye characteristics are formed. The characteristics shown by the sloping lines in fig. 2g nl. The resulting characteristics are sci; and are found using the convolution operation of the impulse response (Fig. 2c)

and the impulse response of the scan standard conversion (Fig. 2a or b). As can be seen from the resulting impulse responses, they have unwanted amplitude spikes, which cause the past image field to be remembered too well and superimposed on the original TV image field.

According to the proposed method, when converting a field sweep standard, they are repeated with successively y, i.e. Lens amplitude (Fig. Over b), so the resulting impulse response is obtained without outliers and has a more rectangular envelope (ozg. Sv, d). Due to this, flicker is suppressed. The TV images are inherent in the standard interlaced scan and at the same time the distortions of the mobile TV image are reduced, which arise as a result of the imposition of successive fields upon repetition of the original fields. In fact, a decrease in the amplitude of the fields repeated in reading reduces the intensity (contrast) of the previous field in comparison with this and thereby reduces the interference in a mobile TV image.

The degree of reduction of the amplitude of the TV signals of the repeated fields depends on the parameters of the reproduced TV image (brightness, contrast, the presence of fine details), and on the conditions of its observation (external illumination, distance of observation), but most of all on the dependence of the effective brightness on time . The attenuation coefficients are defined as additions to a unit of values of the dependence of effective brightness on time (Fig. Sv, d) -. Taking into account the constant time, the attenuation characteristic (about 50 ns), the attenuation coefficient of the repeatable field, when converted to a line scan with a frame rate of 50 Hz, will be 0.4-0.6. The working values of the attenuation coefficient are verified experimentally when implementing the method.

A device for reproducing a TV signal with interlaced decoding (Fig. 4) contains an analog-to-digital converter (ADC) 1, two memory blocks 2 and 3, a multiplexer 4, a digital multiplier 5, a factor b former, a control block 7, a digital-analog converter (CDL ) 8, reproducing unit 9n block 10 sweeps. The device works as follows. The input TV signal is digitized: then the form is into ADC 1. The digital signal is fed to two memory blocks 2 and 3, where the even and odd fields of the original TV image are stored respectively. Through multiplexer 4 (which may be absent if its functions are performed by the memory blocks themselves), signals read from memory blocks 2 and 3 are delivered to a digital multiplier 5, to the second input of which signals are received that are proportional to the required attenuation coefficients. The latter are produced by a factor former shaper, which can be implemented as a permanent storage device storing the values of the coefficients. The control unit 7 generates all types of pulse sequences necessary for ensuring the normal operation of the remaining blocks from the sequence of sync pulses of the input signal. After the digital multiplier 5, the signal arrives at the DAL 8 and in analog form to the reproducing unit 9, the sweep in which with the required standardized frequencies is carried out by the unit 10 sweeps. The invention allows (with regard to the properties of vision) to eliminate the flickering of the reproduced image and at the same time prevent the occurrence of distortion of the moving image - without | the use of an adaptive mode, which requires for its implementation motion detection by comparing video signals of successive frames or fields using additional blocks of frame memory. Devices that implement the proposed method are much simpler than devices that implement the known method. In some cases, with line-by-frame playback with a frequency of 50 frames per second, they will be even simpler than scan-play playback devices suitable only for still images, due to a 1-bit reduction in the memory size. An exceptional motion detector usually contains at least a memory on the field, memory per line, digital arithmetic unit and control element. At the present level of integration, 100-150 chips will be required to implement such a block. At the same time, the savings in hardware costs will lead to substantial savings in the required power supply. Due to the simplicity of the devices that implement the proposed method of playback, they could be used in video monitors at the current level of integration of i-chips of storage devices, and an increase in the degree of integration, the tendency to which is not reduced, will allow to use the proposed method in television receivers.

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Claims (1)

METHOD FOR PLAYING A TV SIGNAL WITH INTERMEDIATE DECOMPOSITION, based on the one-time memorization of each field of the television signal, h-fold line-by-line reproduction of the memorized fields on the scan, where η = 2,3,4 ,. .., while scanning the screen horizontally is carried out at a speed of times and times, and vertically p / 2 times greater than the interlaced decomposition of the original television signal, characterized in that, in order to simplify the implementation of the method, each time line-by-line reproduction of the television signal of each once stored field is successively reduced in amplitude, with a decrease. amplitudes are produced by the formula TO; = 1-1 ₉ (έ) [('-0 V _c ], where is the attenuation coefficient; L ₃ (U is the dependence of the effective brightness on time; ^ s - playback period of fields. To the original tme. Fig.! P42905