JPH08195940A - Wide television signal processor - Google Patents

Abstract

PURPOSE: To reduce degradation of image quality of the detected signal for multiplexing VH signals on a transmission side by multiplexing the vertical high-frequency component of a luminance signal to the vertical no-image part of a letter box and transmitting the component after the vertical high-frequency component is generated by a prescribed circuitry constitution. CONSTITUTION: The luminance signal that the wide television signal 100 of a sequential scanning having prescribed number of scanning line and aspect ratio outputs is inputted in a horizontal low-pass filter 101. Because the filter 101 performs the 1/3 compression in a horizontal direction for a VH signal and multiplexes the signal in the vertical no-image part of the screen of a letter box, band limiting is performed for the horizontal frequency of the luminance signal. Further, the output signal of the filter 101 is inputted in a 4-3 conversion high-pass filter 105. In the filter 105, the 4-3 conversion and a low-frequency shift are performed, the high-frequency component of the luminance signal is converted into a vertical band and an effective number of scanning line is converted. Next, the sequential scanning is converted into an interlaced scanning in a sequential interlaced converter 106, the signal is inputted in a multiplier 402, this signal is defined as a detected signal and the gain of the VH signal is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a high image quality and a high aspect ratio as compared with the current television while maintaining compatibility with the current television broadcasting within the transmission band used in the current television broadcasting. Images with a large ratio can be transmitted,
The present invention relates to a signal processing device of a transmission device of a wide-box television signal of a letter box system.

[0002]

2. Description of the Related Art Current color television broadcasting is based on the NTSC system of 525 scanning lines in Japan and the United States.
1 interlace scanning, luminance signal horizontal bandwidth 4.2 MHz, aspect ratio 4: 3 (for example, refer to the literature: Broadcasting Technology Sosho Color Television, edited by Japan Broadcasting Corporation, Japan Broadcasting Publishing Association, 1961) However, Showa 3
More than 30 years have passed since it started in 5 years. Meanwhile, various new television systems have been proposed in response to the demand for high-definition screens and the improvement in performance of television receivers. In addition, the contents of the programs to be provided themselves are changing from simple studio programs and relay programs to programs with higher image quality and more realistic images, such as cinema-sized movie broadcasts.

Against this background, a wide television signal broadcasting system has been proposed which is compatible with the current broadcasting and has a wide screen. So-called second generation EDT
This is known as the V provisional method, and the number of effective scanning lines is compressed from 480 to 360 per frame, and black portions (hereinafter referred to as non-image areas) are left and right above and below. By doing so, the aspect ratio becomes 16: 9, but the vertical resolution drops, so the components from 360 TV lines to 480 TV lines are transmitted as vertical high frequency components (hereinafter referred to as VH signals) especially in the case of still images. There is a need to. Usually this VH
The signal is transmitted in the upper and lower non-picture areas. Furthermore, when using a 1: 1 progressive scan as a signal source,
A so-called vertical time high frequency component (hereinafter, referred to as a VT signal) generated when converting to 2: 1 interlaced scanning is transmitted. This VT signal is also transmitted by the upper and lower non-picture parts. In order to increase the horizontal resolution, the current horizontal resolution of 4.2MHz
The horizontal high-frequency component (hereinafter, HH
In the case of a still image, it is multiplexed and transmitted as a signal).

A wide television signal has 525 horizontal scanning lines and 1: 1 sequential scanning, and a horizontal frequency band of a luminance signal is about 6 MHz. The number of effective scanning lines is 480. On the other hand, a normal television signal conventionally used has a horizontal scanning line number of 525, a 2: 1 interlaced scanning, and a luminance signal horizontal frequency band of about 4.2 MHz. It is mainly used in current NTSC television broadcasting. Second generation EDTV that transmits wide television signals while maintaining compatibility with current NTSC television broadcasting
In the provisional system, in order to maintain compatibility with the transmission path, it is necessary to perform signal processing for converting a wide television signal into 525 scanning lines, 2: 1 interlaced scanning, and a luminance signal horizontal frequency band of 4.2 MHz. The signal generated by this conversion process is VH
Signals, VT signals, and HH signals, among which the signals recommended to be adaptively transmitted by the motion detection signal are the VH signal and the HH signal.

FIG. 4 is a block diagram showing an example of a wide television signal processing apparatus compatible with the second generation EDTV provisional system. 525 horizontal scanning lines (480 effective scanning lines)
The luminance signal output from the progressive-scanning wide television signal source 100 having an aspect ratio of 16: 9 is a horizontal low-pass filter (= low-pass filter, hereinafter referred to as LPF) 10
Input to 1. The horizontal LPF 101 compresses the VH signal in the horizontal direction by ⅓, and limits the horizontal frequency of the luminance signal to about 1 MHz for multiplex transmission in the upper and lower non-image parts of the screen. The output signal of the horizontal LPF 101 is input to a 4-3 conversion vertical high pass filter (= high pass filter, hereinafter referred to as HPF) 401. 4-3 conversion vertical HPF40
In 1, the 4-3 conversion and the low frequency shift are performed to convert the vertical high frequency components of the luminance signal (the components of about 360 TV lines to 480 TV lines) to the vertical low frequency bands of 0 to 120 TV lines. The number of effective scanning lines is converted from 480 to 360. Further, a sequential-interlace converter (hereinafter, P-
(Hereinafter referred to as I converter) 106, the VH signal is converted from sequential scanning to interlaced scanning, and 180 scanning lines are thinned out from 360 scanning lines and extracted. P-I converter 1
The output signal of 06 is input to the multiplier 402. Since the VH signal is particularly effective for still images, the multiplier 402 uses the interlaced luminance detector of the main image part having a vertical frequency band of up to about 360 TV lines as an input signal for the interlaced motion detector. The motion detection signal 403 generally controls the gain of the VH signal for each pixel. For example,
The interlaced motion detector 403 detects the motion for each pixel, and outputs 8 when it is a perfect stillness determination and 0 when it is a perfect motion determination.
In the meantime, when it is determined, 1 to 7 are output as motion detection signals depending on the degree of motion. As shown in (Equation 1), the multiplier 402 uses the motion detection signal k (0 ≦ k ≦ 8) for P
The gain of the output signal S of the −I converter 106 is controlled, and the still image component is extracted.

[0006]

[Equation 1]

The output signal of the multiplier 402 is sent to the vertical arrangement processing section and subjected to processing such as 15 Hz modulation and horizontal 1/3 compression, and the VH signal is multiplexed and transmitted in the upper and lower non-picture sections.

[0008]

However, in the above-mentioned conventional configuration, in the example of the wide television signal processing device corresponding to the second generation EDTV provisional system, the VH is detected by the motion detection signal of the interlace motion detector 403.
Since the signal gain is controlled, a fast moving image cannot be detected due to a motion detection error due to interlaced scanning, for example, a frame difference (the calculation distance in the time direction becomes 1/30 seconds) processing, and the image is mistaken for a still image. It is easy to detect. The interlace motion detector 403 has a vertical frequency of about 360.
Since the interlaced luminance signal of the main picture part having a band up to TV lines is used as an input signal, it is erroneously detected as still when a vertical frequency of about 360 TV lines to 480 TV lines is moving, and it is erroneously detected as still. There is a problem that VH signals are erroneously multiplexed and transmitted.

The present invention solves the above-mentioned conventional problems. In the second generation EDTV provisional system, the VH on the transmitting side is used.
An object of the present invention is to reduce the image quality deterioration due to the detection error of the motion detection signal for signal multiplexing, reduce the crosstalk between the VH signal and the VT signal on the receiving side, and improve the image quality of wide television.

[0010]

In order to achieve this object, a wide television signal processing device of the present invention inputs a luminance signal of a progressive scanning wide television signal source having a vertical frequency band up to about 480 TV lines. And a non-interlaced motion detector that outputs a motion detection signal, and a vertical HPF that extracts the high frequency component of the vertical frequency of the luminance signal of the progressive scan wide television signal source having a vertical frequency band of up to about 480 TV lines. And a multiplier for controlling the gain of a signal whose vertical frequency is band-limited by the vertical HPF with a motion detection signal, and the number of effective scanning lines of the signal whose gain is controlled by the multiplier is converted from 480 to 360, Low frequency conversion 4-3
The VH signal is extracted by the circuit composed of the conversion vertical HPF, the output signal of the 4-3 conversion vertical HPF is converted from the sequential scanning to the interlaced scanning, and then input to the vertical arrangement processing unit, and the VH signal is input to the top and bottom of the screen. It has a configuration in which it is multiplexed and transmitted to the non-picture portion.

[0011]

According to the present invention, the VH signal is generated from the still picture component extracted by the motion detector for non-interlace according to the above construction. Therefore, it is not necessary to use the interlaced motion detector, and the error in motion detection is reduced as compared with the case where the conventional interlaced motion detector is used. Further, since the motion detector for non-interlaced inputs the luminance signal of the progressive scanning wide television signal source having the vertical frequency band up to about 480 TV lines, the signal component of the vertical frequency of about 360 TV lines to 480 TV lines is input. If is moving, it will not be erroneously detected as stationary. further,
By providing a vertical HPF in front of the multiplier and dropping the vertical low-frequency component including the DC component, even if an error occurs in the motion detection signal of the non-interlaced motion detector, the vertical low-frequency component including the DC component is generated. It is possible to prevent a vertical high frequency component, which is a VH signal, from being generated due to the level fluctuation of the component. As a result, crosstalk between the VH signal and the VT signal on the receiving side is reduced, and the image quality of wide television is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wide television signal processing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a circuit relating to the generation of a VH signal in the wide television signal processing apparatus of the present invention. The luminance signal of the progressive scanning wide television signal source 100 with 525 horizontal scanning lines (480 effective scanning lines) and an aspect ratio of 16: 9 is input to the horizontal LPF 101 and the horizontal band is limited to about 1 MHz. . Further, the luminance signal of the wide television signal source 100 is input to the non-interlaced motion detector 104 and outputs a motion detection signal. The output signal of the horizontal LPF 101 is input to the vertical HPF 102, and the vertical high frequency component is extracted. The vertical HPF 102 is
Even if an error occurs in the motion detection signal of the non-interlaced motion detector 104, it is possible to prevent the vertical high frequency component, which becomes the VH signal, from being generated due to the level fluctuation of components other than the VH signal including the DC component. It is a filter for. Therefore, a vertical HPF having a relatively steep characteristic capable of extracting a VH signal, for example, a characteristic of −6 dB in 360 TV lines is used. Alternatively, for example, a 7-tap vertical filter represented by (Equation 2) may be used.

[0014]

[Equation 2]

FIG. 2 shows the frequency characteristics of the 7-tap vertical filter shown in (Equation 2). The vertical HPF expressed by (Equation 2) is a filter for removing the vertical low-frequency component including the DC component with a small number of taps, and is -6d in about 130 TV lines.
It has the characteristics of B and extracts more than 130 TV components. Components other than VH signals of about 130 TV lines to 360 TV lines are also extracted, but 4-3 conversion vertical HP in the latter stage
Since the VH signal is extracted by F105, there is no big problem. The output signal of the vertical HPF 102 is input to the multiplier 103, and the gain is controlled by the motion detection signal output from the non-interlaced motion detector 104. The non-interlaced motion detector 104 outputs 8 as a motion detection signal at the time of complete stationary determination, 0 at the time of complete motion determination, and 1 to 7 as a motion detection signal depending on the degree of motion during the determination in the meantime. In the multiplier 103, the vertical HPF 102 is calculated by the motion detection signal k (0 ≦ k ≦ 8) as shown in (Equation 3).
The gain of the output signal S is controlled and the still image component is extracted.

[0016]

(Equation 3)

Since the non-interlaced motion detector 104 includes the field difference (the calculation distance in the time direction is 1/60 seconds), the detection error for fast motion is reduced as compared with the motion detector for the interlaced scanning signal source. be able to. The input signal of the non-interlaced motion detector 104 is the luminance signal of the wide television signal source 100, and in particular, has a vertical frequency band up to about 480 TV lines. Therefore, as described in the conventional example, when the vertical frequency of the luminance signal is moving from about 360 to 480 TV signal components, it is erroneously detected as still and the VH signal is erroneously multiplexed and transmitted during a moving image. There is no. Further, when the scene change is detected in the non-interlaced motion detector 104, 0 is output as the motion detection signal so that the output signal of the multiplier 103 becomes 0, and when the scene change is not detected. May have a scene change detector to output a motion detection signal. As a result, VH is mistakenly changed at the scene change.
It is possible to prevent signals from being multiplexed. Since the non-interlaced motion detector 104 has a scene change detector, there is a delay difference between the video signal for generating the VH signal and the motion detection signal for controlling the gain of the signal, but the VH signal is generated. The video signal system for this purpose may be provided with a memory for delay compensation. For example, a memory for delay compensation is provided between the horizontal LPF 101 and the vertical HPF 102 of FIG. 1, or between the vertical HPF 102 and the multiplier 103, or between the multiplier 103 and the 4-3 conversion vertical HPF 105. The output signal of the multiplier 103 is a 4-3 conversion vertical H
It is input to the PF 105. 4-3 conversion vertical HPF105
Then, by performing 4-3 conversion or low frequency shift, the vertical high frequency components of the luminance signal (components from about 360 TV lines to 480 TV lines) are converted to vertical low frequency bands from 0 to 120 TV lines, and are effective. The number of scanning lines is converted from 480 to 360. For example, 15 having the frequency characteristic shown in FIG.
A vertical tap filter is used. The 15-tap vertical filter shown in FIG. 3 has a flat characteristic at about 360 TV lines or more and extracts a vertical high frequency component of about 360 TV lines or more. The output signal of the 4-3 conversion vertical HPF 105 is input to the P-I converter 106, the VH signal is converted from sequential scanning to interlaced scanning, and 180 scanning is performed from 360 scanning lines.
Thin out the scan lines of the book. The output signal of the P-I converter 106 is sent to the vertical arrangement processing section, where it is subjected to processing such as 15 Hz modulation and horizontal 1/3 compression, and the VH signal is multiplexed and transmitted in the upper and lower non-picture sections. The horizontal LPF 101 may be provided before the multiplier 103, before the 4-3 conversion vertical HPF 105, or after the 4-3 conversion vertical HPF 105.

[0018]

As is clear from the above description, in a so-called letterbox type wide television signal processing device that widens the screen while maintaining compatibility with the current television broadcasting system, a motion for non-interlace Since the VH signal is generated from the still image component extracted by the detector, it is not necessary to use an interlaced motion detector, and a motion detection error can be reduced as compared with the case of using a conventional interlaced motion detector. Can be reduced. Also,
The motion detector for non-interlace has a vertical frequency of about 48.
Since the luminance signal of the progressive scan wide television signal source having a band up to 0 TV lines is input, the vertical frequency is about 360.
When the signal components of TV lines to 480 TV lines are moving, it is not erroneously detected as still. Further, by providing the vertical HPF in front of the multiplier, an error occurs temporarily in the motion detection signal of the non-interlaced motion detector, which causes a DC error.
Even if the level of the vertical low-frequency component including the component fluctuates, it is possible to prevent the pseudo VH component from being generated. As a result, crosstalk between the VH signal and the VT signal on the receiving side is reduced, and the image quality of wide television is improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a wide television signal processing device according to an embodiment of the present invention.

FIG. 2 is a frequency characteristic diagram of an example of a vertical high pass filter according to an embodiment of the present invention.

FIG. 3 is a frequency characteristic diagram of an example of a 4-3 conversion vertical high pass filter according to the embodiment of the present invention.

FIG. 4 is a block diagram of an example of a conventional wide television signal processing device compatible with a second generation EDTV provisional system.

[Explanation of symbols]

 100 Wide TV signal source 101 Horizontal LPF 102 Vertical HPF 103,402 Multiplier 104 Non-interlaced motion detector 105,401 4-3 conversion Vertical HPF 106 PI converter 403 Interlaced motion detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoichi Hirose Yoichi Hirose 3-3 Amishima East, Kohoku Ward, Yokohama City, Kanagawa Matsushita Communication Industrial Co., Ltd. (72) Inventor Yukiko Seto 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A letter box type transmitter for transmitting a wide television signal having an aspect ratio of 16: 9 while being compatible with a current television signal standard having an aspect ratio of 4: 3. A motion detector that outputs a motion detection signal from a progressive scanning luminance signal, a vertical high-pass filter that band-limits the vertical frequency of the progressive-scanning luminance signal of the wide television signal source, and a vertical frequency band-limiting by the vertical high-pass filter. A multiplier that controls the gain of the signal obtained by the motion detection signal of the motion detector, and the effective scanning line number of the signal whose gain is controlled by the multiplier is converted from 480 lines to 360 lines, and low-pass conversion is performed. It is characterized by having a circuit composed of a 4-3 conversion vertical high-pass filter, and the vertical high-frequency component of the luminance signal is generated by the above circuit configuration. A wide television signal processing device, characterized in that after being formed, the upper and lower non-picture portions of the letterbox are multiplexed and transmitted. 2. The motion detector outputs a motion detection signal that sets the output signal of the multiplier to 0 when a scene change is detected, and outputs a motion detection signal when a scene change is not detected. The wide television signal processing apparatus according to claim 1, further comprising a scene change detector. 3. A horizontal low-pass filter for band-limiting the horizontal frequency of a luminance signal for progressive scanning of a wide television signal source, before the vertical high-pass filter according to claim 1, or before the multiplier according to claim 1. Alternatively, the wide television signal according to claim 1, wherein the wide television signal is provided before the 4-3 conversion vertical high-pass filter according to claim 1 or after the 4-3 conversion vertical high-pass filter according to claim 1. Processing equipment.