JPH07274129A - Television signal processor - Google Patents

Abstract

PURPOSE:To obtain a decoding processing without increasing a circuit scale when a MUSE signal improving an animation area is receptionprocessed. CONSTITUTION:A MUSE-NTSC converter 102 converts the MUSE signal into the number of the scanning lines of a standard television signal. A three- dimensional Y/C separation device 103 separates a luminance signal Y and a chrominance signal C. The luminance signal Y is inputted to first pass band separation means (LPF 104 and adder 108) different in cut off frequencies and second band pass separation means (LPF 105 and adder 109). The low frequency components of the respective separation means are inputted to an adder 112 through a mixing circuit 106. The high frequency components of the respective separation means are filtering-processed between fields to an appropriate area by a field memory 110 and an adder 111 through a mixing circuit 107.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a high-definition television signal having a scanning line number and an aspect ratio different from the scanning line number and aspect ratio of a standard television signal to a standard television signal or a high-definition television signal. The present invention relates to a television signal processing device that converts a signal into a television signal having a different number of scanning lines and an equal aspect ratio.

[0002]

2. Description of the Related Art High integration of LSI, high operating speed,
In particular, digital signal processing of video signals has become widespread due to the increase in memory speed, capacity, and price ratio. Further, as a television receiver, a large screen and high definition are required. In order to meet these demands, the Japan Broadcasting Corporation has adopted MUSE (MULTIPLE SUBNYQUIST SAMPLING ENCO) as a high-definition television transmission system in Japan.
DING) method is being developed. In this system, the number of scanning lines is 1125, which is more than double that of the current standard television system, and the aspect ratio is 16: 9. further,
Since offset sub-sampling processing between fields and frames is performed and band compression is performed, it is not compatible with the current standard television system and requires a dedicated receiver. On the receiver side, a large-capacity memory such as a large number of frame memories and a decoder equipped with a large number of LSIs are required for displaying on a display. Therefore,
Even with the remarkable progress of LSI technology, a high-definition television receiver becomes a very expensive receiver as compared with a standard television receiver.

Therefore, in the transitional period of the spread of high-definition television receivers, programs of high-definition television transmission system can be viewed, but high definition is less expensive than that of the original high-definition television transmission system. Aspect ratio 16: 9
There is a demand for the above-mentioned television receiver, or a system conversion device for converting a system of a television signal of a high-definition television transmission system and viewing it by a standard television system receiver.

In order to meet the above request, MUSE-NTS
C converters have been developed. As an example, there is a device shown in Journal of Television Engineering Vol.47 No.7 1993 P (29) 957. This will be briefly described below.

FIG. 5 shows a MUSE-NTSC converter. The MUSE signal input to the input terminal 501 is the MU
In the SE-NTSC conversion basic unit 502, MUSE decoding processing is performed and the number of scanning lines is converted to 525. Next, the data is input to the inter-field interpolation unit 503, subjected to inter-field interpolation processing, and the inter-field aliasing component is removed. Next, the inter-frame interpolating unit 504 forming the three-dimensional Y / C separating unit removes the aliasing component between the frames and outputs the result.

The MUSE-NTSC conversion basic unit 502 is
Low pass filter (LPF) 511, A / D converter 52
2, a MUSE signal processing unit 523, a memory 524, and a system conversion unit 525. From the method converter,
A signal with 525 scanning lines is obtained. This signal is input to the inter-field interpolation unit 503. The inter-field interpolation unit 503 includes an LPF 521, a subtractor 522, a field delay unit 523, adders 524 and 525, and a D / A converter 5.
26. A high frequency component is obtained from the adder 522, and this component is inter-field interpolated by the field delay unit 523 and the adder 524, and is added to the low frequency component by the adder 525. The output of the D / A converter 526 is input to the A / D converter 531 of the interframe interpolation unit 504. The output of the A / D converter 531 is added between frames by the frame delay unit 532 and the adder 533. The mixer 534 is controlled by the image motion information detected by the motion detector 505, and selectively derives the output of the A / D converter 531 for a moving image and the output of the adder 533 for a still image.

In addition, the literature ITEJ Technical Report Vol.16
No. 7 pp. 7 to 12 show techniques for improving the image quality in the moving image area in the MUSE method. This will be briefly described below.

FIG. 6 is a system diagram for improving the image quality of the moving image area in the MUSE system. Sampling frequency 4
The image signal digitized to 8.6 MHz is passed through the one-dimensional low-pass filter 601 in the horizontal direction, and converted to 32.4 MHz by the sample rate conversion unit 602. Then, the next two-dimensional wideband in-field prefilter 603 performs band limitation in the diagonal direction. Next, LPF60
4, a subtractor 605, an inter-field vertical filter 606,
By the adder 607, vertical low-pass filtering processing is performed between fields for components of horizontal 8 MHz or higher. Next, in the line offset sub-sampling unit 608, line offset sub-sampling is performed every two frames to reduce the sample rate to 16.2 MHz, D / A converted, and then analog-transmitted in a band of 8.1 MHz. On the side of the decoder, the transmission signal is A / D converted and clock reproduction is performed, and processing is performed almost in the reverse of the encoder side. The field internal post-filter 611 performs field interpolation, and then the LPF 612 and the subtractor 61.
3, the inter-field vertical filter 614 and the adder 615 apply vertical low-pass filtering processing to components of 8 MHz or higher, and then the sample rate conversion unit 616
Returning to the original sample rate.

That is, in the moving image area on the sending side, a high frequency signal of 8 MHz or more in the horizontal direction is subjected to vertical low-pass filtering between fields and added with a signal of 8 MHz or less in the horizontal direction. This signal is line offset subsampled and transmitted. The receiving side performs decoding by performing signal processing reverse to that of the sending side.

[0010]

SUMMARY OF THE INVENTION Here, the MUSE signal improved in image quality in the moving image area as described above is converted into a conventional MU signal.
When decoding with the SE-NTSC converter, there are the following problems. When the MUSE-NTSC converter performs the inter-frame aliasing removal as well as the inter-frame aliasing removal in the still image area, the inter-field aliasing component has a horizontal frequency of about 4 MUSE signals.
Since it exists in the high frequency components of MHz and above, filtering processing between fields is performed for this area. As for the moving image area, the area to be subjected to the inter-field filtering process for improving the image quality is the high frequency component whose horizontal frequency is 8 MHz or more. Therefore, in order to perform the inter-field processing on the moving area, the horizontal frequency components to be processed are different, so that a new field memory for moving image processing is required, resulting in an increase in circuit scale and an increase in cost.

Therefore, according to the present invention, the M image with improved moving image area is provided.
It is an object of the present invention to provide a television signal conversion processing device that performs decoding processing without increasing the circuit scale when receiving and processing USE signals.

[0012]

SUMMARY OF THE INVENTION The present invention is a means for converting a MUSE signal into a standard television signal.
Interpolation means for inputting a USE signal, having synchronous reproduction means, control signal reproduction means, and means for performing non-linear de-emphasis, and inputting an output signal of the means for performing non-linear de-emphasis to perform field interpolation Scanning line conversion means for converting the number of scanning lines, time axis conversion means for time axis conversion, and motion detection means for detecting image motion information as means for three-dimensional Y / C separation. A cutoff frequency is provided for the output signal of the means for performing at least three-dimensional Y / C separation, which has at least a first calculation means for performing addition / subtraction between frames and a first filter processing means for performing in-field filtering processing. Second and third filter processing means for extracting low frequency components different from each other, and the second and third filter processing based on the input signals of the second and third filter processing means. The second and third computing means for subtracting the output signal of the processing means, the output signal of the second computing means and the output signal of the third computing means are set to the magnitude of the output signal of the motion detecting means. A first signal mixing means for mixing in accordance with the above, a memory means for storing one field of a video signal, and a fourth means for performing addition between fields for the output signal of the first signal mixing means by using the memory means. And a second signal mixing means for mixing the output signal of the second filter processing means and the output signal of the third filter processing means according to the magnitude of the output signal of the motion detecting means. A signal processing device comprising: a fifth arithmetic means for adding the output signal of the fourth arithmetic means and the output signal of the second signal mixing means.

[0013]

In the apparatus for converting a MUSE signal with improved image quality in the moving picture area into a standard television signal, the field memory is shared by the signal processing in the moving and static area by the above-mentioned means, so that a minimum hardware scale is achieved. With respect to the still image area, it is possible to remove aliasing between frames and fields. Further, by performing inter-field processing in the time direction on the moving image area as well, the resolution and S / N ratio can be improved, and a standard television signal with higher image quality than before can be obtained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. Input terminal
101 is supplied with a MUSE signal with improved image quality in the moving image area, and in the MUSE-NTSC converter 102, MUSE signal is supplied.
Of the USE decoding processing, only signal processing (field interpolation processing) within the same field, which is processing at the time of moving image, is performed to obtain 1125 2: 1 interlaced signals. Further, the scanning line number conversion process as the MUSE-NTSC system conversion process is performed, and the 1125 2: 1 interlaced signal is converted to the 525 2: 1 interlaced signal.

This signal is input to the three-dimensional Y / C separation device 103. FIG. 2 shows a block diagram of the three-dimensional Y / C separation device 103. The three-dimensional Y / C separation device 103 is an inter-frame Y / C separator that performs arithmetic processing between frames of an input signal.
It is composed of a separation circuit 201, an in-field Y / C separation circuit 202 which performs arithmetic processing between scanning lines of an input signal, and a motion detection circuit 203 which detects a motion of a picture of the input signal. In the still image portion that does not change between frames, the inter-frame Y / C separation circuit 201 is used, and the fact that the phase of the color signal is inverted for each frame is used to calculate the difference between the sum of the same pixels one frame before and the difference. Then, the luminance signal Y and the color signal C are separated. In the moving image portion, processing is performed between different images that have moved between frames, and accurate separation becomes impossible. So the motion detection circuit
At 203, the in-field Y / C separation circuit 202 is switched. The in-field Y / C separation circuit 202 separates the luminance signal Y and the chrominance signal C by calculating the sum difference of the upper and lower scanning line signals in the same field. The luminance signal Y from each of the Y / C separation circuits 201 and 202 is supplied to the mixing circuit 204, and the color signal C is supplied to the mixing circuit 205. Mixed circuit
204 and 205 are controlled by a motion detection signal from the motion detection circuit 203, and when the image motion is large, the inter-frame Y /
The ratio of signals from the C separation circuit 201 is increased, and when the image movement is small, the ratio of signals from the inter-frame Y / C separation circuit 202 is increased and output.

The three-dimensional Y / C separation device 103 removes the aliasing component between frames and outputs it. Also, a motion detection signal from the motion detection circuit 203 is output. It returns to FIG. 1 and demonstrates. The luminance signal (Y) output from the three-dimensional Y / C separation device 103 is input to one input terminal of the adder 108 together with the low pass filter 104. The output of the low-pass filter 104 is supplied to the other input terminal of the adder 108. As a result, a low-pass component is obtained from the low-pass filter 104, and a high-pass component is obtained from the adder 108. Further, exactly the same signal processing is performed on the luminance signal (Y) output from the three-dimensional Y / C separation device 103 by the low pass filter 105 and the adder 109. As a result, the low-pass component is obtained from the low-pass filter 105, and the adder 10
High frequency components are obtained from 9. That is, the luminance signal (Y) output from the three-dimensional Y / C separation device 103 is input to one input terminal of the adder 109 together with the low pass filter 105. The output of the low pass filter 105 is supplied to the other input terminal of the adder 109. As a result, the low-pass component is obtained from the low-pass filter 105, and the high-pass component is obtained from the adder 109.

Low pass filter 104, low pass filter
The output of 105 is supplied to the mixing circuit 106. Also adder
The outputs of 108 and adder 109 are supplied to mixing circuit 107. The mixing circuits 106 and 107 are three-dimensional Y / C separation devices 103.
Is controlled by the motion detection signal from. Although a high frequency component is obtained from the mixing circuit 107, inter-field filtering processing is performed on this component. That is, the output of the mixing circuit 107 is supplied to the field memory 110 and the adder 111. The output of the field memory 110 is also supplied to the adder 111. The output of adder 111 is
At 2, it is added to the output of the mixing circuit 106.

In the above structure, a low pass filter
Reference numeral 104 is used for signal processing in the moving image area, and low-pass filter 105 is used for signal processing in the still image area. Then, the region to which the inter-field filtering process is applied to the moving image region becomes a high frequency component whose horizontal frequency is about 3.73 MHz or higher.
Further, in the still image area, the inter-field folding component exists in the high frequency component of the horizontal frequency of about 1.86 MHz or more, and thus the inter-field filtering process is performed on this area. Therefore, a low pass filter
The cutoff frequency of 104 is about 3.73 MHz, and the cutoff frequency of the low-pass filter 105 is about 1.86 MHz. In the mixing circuit 107, the high frequency components of the moving image area and the still image area, which are the outputs from the adders 108 and 109, are mixed and output at a ratio according to the motion detection signal from the three-dimensional Y / C separation device 103. . This signal is input to one input terminal of the field memory 110 and the adder 111. The output of the field memory 110 is supplied to the other input terminal of the adder 111. As a result, the wide area component subjected to the inter-field processing is obtained from the adder 111. Also, the mixing circuit 10
In 6, the low-pass components of the moving image region and the still image region, which are outputs from the low-pass filters 104 and 105, are mixed and output at a ratio according to the motion detection signal. The signal obtained here is input to the adder 112, and is added to the high-frequency component from the adder 111 which has been subjected to inter-field processing. As a result, the adder 112 can obtain a signal that has undergone inter-frame processing and inter-field processing for the still image area and a signal that has undergone inter-field processing for the moving image area.

3 and 4 show another embodiment of the present invention. The parts having the same functions as those of the previous embodiment are designated by the same reference numerals. In the embodiment of FIG. 3, a three-dimensional Y / C separation device is used.
The structure of 114 is as shown in FIG. First,
The structure of the three-dimensional Y / C separation device 114 will be described with reference to FIG. The three-dimensional Y / C separation device 114 has a configuration in which the mixing circuit 204 of FIG. 2 is omitted as compared with the device of FIG. 2, and the rest is the same as the configuration of FIG. Therefore, the luminance signal Y
As for the signal, the signal from the inter-frame Y / C separation circuit 201 (still image Y) and the signal from the intra-field Y / C separation circuit 202 (moving image Y) are directly output from the three-dimensional Y / C separation device 114, respectively. I am trying to output. The former is subjected to signal processing in the still image area by the low-pass filter 105, and the latter is subjected to signal processing in the moving image area by the low-pass filter 104, and then the respective signals are mixed by the mixing circuit 106.
In this example, the signal is mixed and output at a ratio according to the motion detection signal from the motion detection circuit 203. Other operations are the same as those in the previous embodiment.

[0020]

As described above, according to the present invention,
In a device for converting a MUSE signal with improved image quality in a moving image area into a standard television signal, a field memory is shared in signal processing in a moving area, and a three-dimensional Y / It is possible to remove inter-frame folding and inter-field folding by performing inter-frame processing as well as inter-frame processing in the C separation device. Further, regarding the moving image area, the inter-field processing corresponding to the inter-field filtering processing for improving the image quality is performed, so that the resolution and the S / N ratio are improved, and a standard television signal having a higher image quality than before is obtained. be able to.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a three-dimensional Y / C separation device.

FIG. 3 is a structural explanatory view showing another embodiment of the present invention.

FIG. 4 is a diagram showing the configuration of the three-dimensional Y / C separation device shown in FIG.

FIG. 5 is a diagram showing a configuration of a MUSE-NTSC converter.

FIG. 6 is a system diagram for improving the image quality of a moving image area of the MUSE method.

[Explanation of symbols]

101 ... Input terminal, 102 ... MUSE-NTSC converter, 103 ... Three-dimensional Y / C separation device, 104, 105 ... Low pass filter, 106, 107 ... Mixing circuit, 108, 109 ... Adder, 11
0 ... Field memory, 111, 112 ... Adder, 113 ... Output terminal, 114 ... Three-dimensional Y / C separation device, 201 ... Inter-frame Y / C separation circuit, 202 ... In-field Y / C separation circuit,
203 ... Motion detection circuit.

Claims (3)

[Claims] 1. A MUSE-NTSC conversion means for converting a MUSE signal into a signal of a standard television signal system and the number of scanning lines, and an output signal of the MUSE-NTSC conversion means are supplied, and a luminance signal and a color are provided by motion adaptation. A brightness / color separation means for separating the brightness / color separation means and a brightness signal output from the brightness / color separation means;
A first separating means for separating a first low-frequency component and a first high-frequency component at a frequency of, and a luminance signal output from the luminance / color separating means,
Second separating means for separating a second low-frequency component and a second high-frequency component at a frequency of, and the first low-frequency component and the second low-frequency component from the first and second separating means. A first range component is supplied to obtain a mixed output in which a mixing ratio of the first and second low range components is changed according to the image movement.
Mixing means, and the first high frequency component and the second high frequency component from the first and second separating means are supplied, and the first high frequency component and the second high frequency component are mixed in accordance with image movement. Second to obtain mixed output with variable ratio
Mixing means, inter-field filtering means for performing inter-field filtering processing on the output of the second mixing means, and output between the inter-field filtering means and the output of the first mixing means. A television signal processing device, comprising: an addition unit. 2. The brightness / color separation means comprises a first brightness signal based on inter-frame brightness / color separation and an in-field brightness / color separation signal.
A second luminance signal is obtained by color separation, the first luminance signal is directly supplied to the second separating means, and the second luminance signal is directly supplied to the first separating means. The television signal processing apparatus according to claim 1, wherein the television signal processing apparatus is a television signal processing apparatus. 3. The first separating means has a separating frequency of 3.73 MHz, and the second separating means has a separating frequency of 1.8.
The television signal processing apparatus according to claim 1, wherein 6 MHz is used as the separation frequency.