JPH04334279A - Horizontal blanking correction device - Google Patents

Abstract

PURPOSE:To obtain the video signal satisfying the prescribed standard by suppressing the degradation of the picture quality in the center part of the screen and correcting the blanking width. CONSTITUTION:For the correction of the blanking width, the omission amount of the both ends of the video signal is preliminarlly detected and the expanding processing is performed only for the picture peripheral part existing on the outer side of the reference point according to the omission amount. The actual deviation from the standard of the video signal generated by the video editing and the digital video effect processing (DVE) is different according to the number of times of the processing but it never exceeds 1mus on the one side. As the replenishment method for the omission part, the constant rate expanding system in the picture peripheral part according to the omission amount is applied in this embodiment, considering the smoothness after the execution of the processing, the influence on the original picture signal and circuit scale.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a correction device for processing a video signal whose horizontal blanking width has been expanded to return it to a blanking width that conforms to video signal standards.

More specifically, the present invention relates to a device for correcting blanking width to an appropriate value in the process of producing a program for television broadcasting.

0003

[Prior art] In the program production process such as production and post-production, video editing and D
When screen composition using VE (digital video effects) or the like is repeated, both ends of the video signal are dropped, and as a result, the horizontal blanking width becomes wider, which may cause a deviation from the standard.

The mechanism by which this blanking width is expanded is as follows.

One of the reasons why the blanking width increases is as follows.
This is a case where the color frame phases do not match during the editing process.

[0006] In video editing systems, editing is performed frame by frame. On the other hand, the color phase in an NTSC signal is a 4-field sequence, and the phase of subcarriers (hereinafter referred to as sc) is reversed by 180° for each frame. Therefore, when editing frame by frame, the sc of the reference system is 1
/2, the phase will shift by 180°, and to compensate for this phase shift, the phase in the horizontal direction (hereinafter referred to as H phase) will be shifted by s.
This results in a shift of half a cycle (140 ns) of c. As a result, both ends of the video signal are dropped and the horizontal blanking width becomes wider.

FIG. 9 shows that when the color phase does not match the reference system, the image H phase shifts in units of 140 ns and the blanking width widens.

[0008] As described above, various types of special effect processing are performed on the video television signal via the video processing section and the video memory. Such a device is usually called a DVE (digital video effect), and it reads input images stored in the video memory from the video memory in real time and processes the data using digital filters and various arithmetic devices. It is generally known that processing of enlargement and reduction by controlling addresses, etc. when reading from video memory, generation of various other signals, and processing of special effects by a combination of multiprocessors and software technology that performs these controls is generally known. It is being

[0009]

[Problem to be Solved by the Invention] However, as program exchange and joint program production with foreign countries are increasing, the problem of deviation from this standard is becoming more and more serious. Therefore, attention must be paid to deviations from the standard, and the actual situation is to deal with this by enlarging the entire screen using techniques such as the DVE's enlargement mode.

[0010] The above-mentioned standards are the US EIA (Elec
tric Industries Association
This refers to the studio video signal standard RS-170A (see FIG. 10) of the NTSC color television system, which was announced by NTSC (On).

[0011] As an actual example of this deviation in video signal standards, there are cases in which it has been pointed out that the H blanking width is larger than the standard in a program provided overseas. More specifically, 10.9±0 shown in Figure 10
．． There are reports of blanking widths of 11.20 to 11.95 μs compared to the 2 μs standard. This problem occurs during DVE processing of title screens, studio insert processing, and when using a handy camera. As a result, a monitor screen appears with left and right screen gaps (the screen gap width is on the order of 0.8 μs).

Regarding the screen chipping rate (missing width), NHK
According to a statistical survey of the programs provided overseas,
It has been reported that the screen width is on the order of 0.8 μs.

[0013] In order to correct this enlargement of the blanking width, in other words, in order to correct the standard deviation of the video signal caused by the omission of the horizontal video signal, the entire video signal is expanded using a conventional DVE or the like. This not only requires expensive equipment, but also has the disadvantage that the image quality in the central part of the screen, which is visually important, deteriorates as well as in the peripheral part.

Furthermore, by processing the screen,
There is also the drawback that the image quality becomes unnatural. For example, if the pattern in the image is a circle, if the image is simply enlarged in the horizontal direction, the entire pattern will become egg-shaped.

[0015] Therefore, in view of the above points, the object of the present invention is to
The objective is to suppress image quality deterioration at the center of the screen and correct blanking width, thereby obtaining a video signal that satisfies a predetermined standard.

[0016]

[Means for Solving the Problem] In order to achieve the above object, the horizontal blanking correction device according to the present invention corrects the blanking width while enlarging only a portion of the screen and suppressing the image quality deterioration of the original video signal. This is to reproduce an image signal that conforms to the RS-170A standard.

That is, the horizontal blanking correction device according to the present invention includes an input means for inputting a digital video signal obtained by sampling an analog video signal at a predetermined sampling frequency, and a method for inputting a digital video signal obtained by sampling an analog video signal at a predetermined sampling frequency. a delay means for giving a delay time and outputting an unprocessed video signal; a Y/C separation means for inputting the digital signal and separating the luminance signal component and the color signal component; an enlargement processing means that performs a predetermined enlargement process on each of them and then mixes them again to output a processed video signal; The apparatus is equipped with a switching means that outputs an area signal and also switches the horizontal blanking area to a synchronization signal component that satisfies specific specifications.

[0018]

[Operation] In the present invention, in order to suppress image quality deterioration in the center of the screen, which is important as visual information in the original video signal, only both ends of the original signal are enlarged and the blanking width is corrected. .

More specifically, in a television input video signal, the synchronization and burst signal components of a video signal that does not conform to the RS-170A standard are replaced with new, regular components. In addition, if the image part of the television input video signal is insufficient, in order to normalize the horizontal blanking width, part of the image signal of the left and right video parts of the actual image signal is used. The portion is enlarged to compensate for the missing portion, correct the image signal to a regular image signal, and obtain a horizontal blanking width that complies with the RS-170A standard.

Here, as a method for correcting the image part, two system areas are divided into a processing signal system and an unprocessed image signal processing system for the television input video signal, and the unprocessed image signal and the processed image signal are separated at the output stage. A method is adopted in which the signals of the image signal system are switched and output, and most of the signals including the central part of the image are used as the unprocessed image part (the central part of the screen), thereby suppressing deterioration of the overall image quality.

When correcting only the left and right video portions of an input image, a reference point is set at the left and right video end portions of the image signal of the horizontal scanning line, where it is visually unnoticeable even after correction, and this reference point is The image outside the point is expanded outward, and the horizontal blanking width is finally adapted to the RS-170A standard.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before explaining one embodiment of the present invention, the principle of blanking width correction according to the present invention will be described first.

FIG. 1 shows an image of the blanking width correction principle. To correct the blanking width, the amount of loss at both ends of the video signal is detected in advance, and in accordance with the amount of loss, only the peripheral portion (2) of the image outside the set reference point is enlarged.

[0024] The deviation in standard of the actual video signal caused by video editing or DVE processing varies depending on the number of times of processing, but does not exceed 1 μs on one side. In the embodiment described in detail below, it is possible to correct image loss of up to 2 μs, including an additional 1 μs margin.

Generally, as a method for filling in missing parts, (i)
Complementing the missing part by repeating or replacing the image peripheral signal (repetition method) (ii) Complementing the missing part by expanding the image peripheral signal at a constant rate or constant width (enlargement method), but the smoothness after processing In consideration of the influence on the original image signal, the circuit scale, etc., this embodiment adopts a constant-rate enlargement method for the image periphery according to the amount of loss.

[0026] The enlargement ratio is determined by taking into consideration the deterioration of the image quality of the original video signal portion due to enlargement and the smoothness of the enlarged portion.
The magnification was doubled.

FIG. 2 shows the compensation range parameters for the missing width at 5/4 times enlargement.

Note that the synchronization and burst signals have been replaced with regular signals.

FIG. 3 is a block diagram showing an entire embodiment of the present invention.

In this embodiment, an analog composite signal or a digital composite signal (4fSC sampling) is assumed as the input video signal. Therefore, when inputting the latter digital composite signal, the A/D converter 2 at the next stage is not required.

NTSC composite input signal is 14.3
After being A/D converted at MHz (4fSC), it is sent to the Y/C separator 4. The Y/C separated image signals are written to 1H memories 6A, 6B and 8A, 8B, respectively. These memories have a 2-line memory configuration and are used alternately for writing and reading. Also, Y
The missing width shown in FIGS. 5 and 6 is detected using the Y (luminance) signal component separated by /C.

In order to detect the missing width as described above, four detection points are provided, and approximately 5I is detected at each point.
The presence or absence of omission is detected based on the brightness level of the RE (the detection level setting can be changed).

Next, the missing portion detection process will be explained.

The input video signal is processed in the following two ways.

One mode is to use it as a symmetrical signal for the above-mentioned image processing, and the other mode is to use it as a signal source for generating a reference signal for a timing signal used for image processing control from an input video signal.

Synchronously separates the input video signal, creates a reference signal for image processing, uses 1H memory to generate a control signal for enlargement processing using an interpolation method, generates a timing signal for the output switching section, and performs rearrangement processing. It generates synchronization signal generation/switching signals for this purpose, as well as timing signals for detecting missing widths of input video signals.

The missing width is predicted in advance by using these timing signals to determine the presence or absence of an image signal by discriminating the luminance level of the Y (luminance) signal component separated by Y/C from the input video signal. The presence/absence status of each of multiple time domains is integrated not in units of one horizontal scanning line but in units of fields, and it is determined that the integrated value is within a predetermined value range.
Display classification is done using LEDs so that the observer can visually judge the situation. In performing the classification display here, one field has 262.4 scanning lines, but if blanks in each time domain are detected in a half of 128 scanning lines or more, the video signal in that time domain is Assuming that the blanking portion is enlarged, the presence or absence of video in that time domain is indicated by LED. Since the omission of the video signal is determined by discrimination of the brightness level, depending on the image, it is conceivable that the omission may be frequently determined based on the judgment output for each scanning line. For this reason, this concern was taken into consideration by conducting the study on a field-by-field basis.

Here, the LED display of the missing width is carried out using four LEDs (total of eight) for each of the four points on the left and right in the horizontal direction. That is, as shown below, four point ranges of 0.2 to 0.6 μs, 0.8 to 1.2 μs, 1.6 to 2.0 μs, and 2.0 μs or more are displayed.

This display of the missing width of the input video signal using the LED is only for informing humans of the state of the input video signal, and the setting of the correction amount of the apparatus according to this embodiment can be determined from this display alone. It was established for the purpose of It does not automatically detect the loss of the input video signal and automatically set the amount of correction based on this. This is because even if there is no luminance component of the video signal, that part is not necessarily a blanking part, and it is possible that the part is a normal black signal as an actual image.

For this reason, in this embodiment, in order to leave this consideration to the human operator, manual setting is used, and the display of the missing width only provides one material for judgment at that time.

In the Y processing section 10 and the C processing section 12, correction (enlargement) is performed in 11 manually set steps (steps of 0.2 μs width) depending on the size of the left and right image missing widths of 0 to 2.0 μs. ) process. This correction is
As shown in FIG. 6, the image outside the reference point is enlarged to cover the missing width. In other words,
In FIG. 6, the image between x(n) and x(m) is complemented based on the image between x(m) and x(m+4).

The reason why the correction interval is manually set in steps of 0.2 μs is because (i) the width of the missing portion is almost constant depending on the material. (ii) If correction is performed line by line, visual smoothness will be lost due to variations in the input image signal level. This is because of the following reasons.

[0043] The correction limit (the limit of the missing width of the left and right video parts is set to 2.1 μs or more in this embodiment). The above-mentioned limit width was determined because it is considered that this process is usually performed once or twice.

Reference numeral 20 denotes a missing position detection display section and a correction step setting section. This part includes the display of the result of detecting the missing width based on the above-mentioned assumption, and the correction step to be actually set can be determined from the picture monitor and the displayed contents without detailed observation with a waveform measuring device. , a setting section for providing input of a correction step to the apparatus.

Although there is no correspondence between the correction step and the missing width, while checking the missing width display and the correction step setting,
By resetting the correction step position, the missing width can eventually be reduced to zero.

The correction step is from 0 μs to 2 μs, 0.
There are a total of 11 stages with a pitch of 2 μs. 16 is a ROM. When the function of this ROM is set to a certain setting value level by the correction step setting section 20, various control data corresponding to the correction step is sent to each control section as the ROM output.

The ROM 16 is further input with a timing signal generated from the input video signal mentioned above, or more precisely, an address signal corresponding to each position of the horizontal scanning line, and is used to determine the control method along with the correction step data. I am doing it. Depending on the amount to be corrected, the method of enlargement processing, the control of the switching point between the processed image and the unprocessed image, etc. are all uniquely determined by the output of this ROM.

Next, with reference to FIGS. 7 and 8, correction (
A specific example of the processing (enlarged) will be explained. Here, FIG. 7 shows a specific example of correction processing when one side of the video signal is missing by 0.2 μs.

Correction of the missing portion is performed by using a video signal with a width four times the width of the missing portion and enlarging this portion. Therefore, in the case of a 0.2 μs loss (3 sample widths), a signal region with a width of 0.8 μs (12 sample widths) is targeted.

Regarding the complementation coefficient used when expanding the luminance signal, as shown in FIG. 8, since 4 samples of the video signal are required to complement one sample width, periodicity can be corrected using 4 samples of data. I decided to have it.

Similar to the luminance signal, the color signal is also 5/4.
Expand by 2x. However, since the bandwidth is narrower than the luminance signal, the I and Q signals are treated as one pair, and the corrected 4
Use the uncorrected value as is for up to the pair, and set 4 for the 5th pair.
A simpler correction process is performed by repeating the value of the second pair.

A part of the image signal output from the A/D converter 2 is directly input to the 1H delay line 22. This is to output the central part of the image as an unprocessed image without deteriorating the image quality.

The corrected (enlarged) color signal and luminance signal are sent to the mixer 24 via the encoder 14. As shown in FIG. 4, the unprocessed image signal output from the delay line 22 (corresponding to the center of the image) and the processed image output from the encoder 14 (corresponding to the left and right ends of the image) The signals are switched at the point "" (see FIGS. 1, 5, 6, 7, and 8), and corrected image area signals (signals in the areas .largecircle. and .largecircle. shown in FIG. 1) are obtained.

This switching between the two images can be performed by dissolve switching or cut switching.

Regarding the horizontal blanking area of the video signal, a BBS (black burst signal) conforming to the RS-170A standard is generated from the ROM 26 and completely replaced with that BBS.

In this way, an analog composite signal is obtained via the D/A converter 28 by replacing the synchronization signal containing the synchronization component and the burst component, which matches the horizontal blanking width of the RS-170A standard.

[0057]

Effects of the Invention As explained above, in the present invention, the signal of the processed image processing system and the signal of the non-processed image processing system are switched at a switching point according to the correction step data. It is possible to obtain a video signal that conforms to a predetermined standard without deteriorating the image quality in some areas.

The horizontal blanking correction device according to the present invention can be used for the following purposes.

(1) Using this apparatus, standardize a program already produced and stored on a magnetic tape or the like into a video signal that conforms to the television broadcasting standard.

(2) It can be used as a production switcher system incorporating the functions of this device in post-production or in the final process of program production at a broadcasting station.

(3) It can be used as an additional function to a time base collector of a VTR and as a switcher for VTR editing functions.

(4) It is also possible to incorporate the present device into a processing device that performs digital video signal processing via a memory, such as into a special effects device that performs digital processing on video signals.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the horizontal blanking correction principle of the present invention.

FIG. 2 is a diagram showing compensation range parameters for missing width during 5/4 times enlargement.

FIG. 3 is a block diagram showing an entire embodiment of the present invention.

FIG. 4 is a block diagram showing the output stage of this embodiment in more detail.

FIG. 5 is a waveform diagram showing the principle of correction (enlargement) in the present invention.

FIG. 6 is a waveform diagram showing the principle of correction (enlargement) processing in the present invention.

FIG. 7 is an explanatory diagram showing 5/4 times enlargement processing.

FIG. 8 is an explanatory diagram showing an example enlargement process of 5/4 times.

FIG. 9 is an explanatory diagram showing a mechanism in which the blanking width is expanded.

FIG. 10 is an explanatory diagram of studio standard EIA RS-170A.

[Explanation of symbols]

2 A/D converter 4 Y/C separation section 6A, 6B 1H memory 8A, 8B 1H memory 10 Y processing section 12 C processing section 14 Encoder 16 ROM 18 Synchronization separation section 20 Missing position detection display section and correction step setting section 22 1H Delay line 24 Mixer 26 ROM 28 D/A converter

Claims (6)

[Claims] 1. An input means for inputting a digital video signal obtained by sampling an analog video signal at a predetermined sampling frequency, and outputting an unprocessed video signal by giving a predetermined delay time to the digital video signal. Y/C separation means for inputting the digital signal and separating it into a luminance signal component and a color signal component; and after performing an enlargement process on each of the luminance signal component and the color signal component. , an enlargement processing means for mixing the processed video signal again and outputting the processed video signal, and switching the processed video signal and the unprocessed video signal at a predetermined timing to output a single video area signal, and a horizontal blanking area. 1. A horizontal blanking correction device characterized by comprising: switching means for switching over to a synchronization signal component that satisfies specific specifications. 2. The horizontal blanking correction device according to claim 1, wherein the enlargement processing means enlarges a predetermined width of the left and right end portions by interpolation processing to complement the image in the image missing portion. 3. According to claim 2, the enlargement processing means changes the position of a reference point that defines the size of the image area to be interpolated according to the size of the image missing part. horizontal blanking correction device. 4. The horizontal blanking correction according to claim 3, wherein the switching means sets a switching point between the processed video signal and the unprocessed video signal in accordance with the position of the reference point. Device. 5. In claim 1, the switching means comprises:
A horizontal blanking correction device characterized in that it replaces the horizontal synchronizing signal component and color burst signal specified in the EIA standard RS-170A. 6. In claim 2, when supplementing the missing video portion, the enlargement processing means performs a 5/4 times enlargement process using a video area approximately 4 times larger than the missing video portion. A horizontal blanking correction device characterized by: