JPH09107510A - Multi-screen image quality improvement circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a video image having natural boundary between video images by avoiding arithmetic operation between video signals in different synchronizing signal timings at boundaries between video images in the multi- screen display device. SOLUTION: A 1st video signal processing circuit 51 generates a 1st luminance signal. A 2nd video signal processing circuit 52 generates a 2nd luminance signal. A 1st selector 53 selects the 1st luminance signal or the 2nd luminance signal and outputs a synthesized luminance signal. A 2nd selector 54 outputs a synthesized luminance signal with a frame in which the synthesis luminance signal for a frame display period is replaced with a frame label signal. A frame width magnification circuit 55 generates a magnified frame signal. The peaking processing and the generation of speed modulation signal based on the synthesis luminance signal with added frame and the magnified frame signal are not conducted at the boundary between the video images.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-screen image quality improving circuit for providing a natural image at a boundary between images when displaying a plurality of image signals having different synchronizations on an image display device. .

[0002]

2. Description of the Related Art In recent years, there has been an increasing need for simultaneously displaying a plurality of images and information. Corresponding to such multimedia, when simultaneously displaying a plurality of video signals with different sync signal timing on one video display device,
Display synthesis technology for multiple video signals is important.

The present invention relates to a multi-screen image quality improving circuit for providing a natural image at a boundary between images.

A conventional multi-screen image quality improving circuit will be described below with reference to the drawings. FIG. 7 is a block diagram of a conventional multi-screen image quality improving circuit, and FIG. 7 is an operation waveform diagram for explaining the operation of the conventional multi-screen image quality improving circuit. The signals shown in FIGS. 7 and 8 correspond to each other.

In FIG. 7, reference numeral 71 is a first video signal processing circuit which receives the first video signal and generates a first luminance signal. A second video signal processing circuit 72 receives the second video signal and generates a second luminance signal. 7
A first luminance signal 3 switches the first luminance signal and the second luminance signal according to the video switching signal, and outputs a synthesized luminance signal.
Selector. A second selector 74 receives the combined luminance signal, the frame level signal, and the frame signal and outputs a frame-added combined luminance signal obtained by changing the combined luminance signal to the frame level during the frame display period. A peaking circuit 75 receives the frame-added combined luminance signal, increases the gain of a certain frequency band component, and generates an output luminance signal. Reference numeral 76 denotes a velocity modulation signal generation circuit which inputs the frame-added combined luminance signal and outputs a velocity modulation signal.

The operation of the multi-screen image quality improving circuit will be described below. First, the first video signal processing circuit 71
The first video signal is input to and the first luminance signal is output. Similarly, the second video signal processing circuit 72 outputs the second luminance signal. Then, the first selector 73
The luminance signal, the second luminance signal, and the video switching signal are input, the two luminance signals are switched by the video switching signal, and the combined luminance signal is output. Next, the second selector 7
At 4, in the frame display period, the frame-added combined luminance signal is output by changing the combined luminance signal to the frame level. Next, the frame-added combined luminance signal is input to the peaking circuit 75 and the velocity modulation signal generation circuit 76, and the output luminance signal with the gain of the specific frequency band component increased and the velocity modulation signal with the first-order differential in the horizontal direction, respectively. Output. In the peaking circuit 75 and the velocity modulation signal generation circuit 76, since the horizontal and vertical continuous calculations are performed at the boundary portion where a certain image and another image are combined, signals having no correlation with each other are calculated, which is unnatural. There was a great image.

[0007]

In the conventional configuration as described above, the first video signal and the frame level signal, and the frame level signal and the second video signal at the boundary portion between the first video and the second video. When an unnatural output luminance signal or speed modulation signal is generated by performing horizontal or vertical calculation such as peaking processing or speed modulation signal generation between, especially when the image of the part adjacent to the frame is a moving image However, there is a problem that an abnormal luminance signal or a velocity modulation signal is generated in the frame display portion.

[0008]

In order to solve the above-mentioned problems, the multi-screen image quality improving circuit of the present invention is different in the boundary portion between images when displaying a plurality of images simultaneously on one image display device. The feature is that the calculation of the video signals is not performed.

According to the present invention, in the boundary portion between the first image and the second image, the horizontal and vertical operations for improving the image quality are not performed, so that the unnatural image which has been generated at the boundary portion in the past. Can be prevented and a more natural image can be provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
A multi-screen image quality improving circuit characterized in that when a plurality of video images are simultaneously displayed on one video display device, different video signals for image quality improvement are not calculated at the boundary between the video images. It is possible to prevent the occurrence of an unnatural image that has occurred at the boundary portion and provide a more natural image.

According to a second aspect of the present invention, there is provided a first video signal processing circuit for inputting a first video signal to generate a first luminance signal, and a second video signal for inputting a second video signal. A second video signal processing circuit that generates a second brightness signal; a selector that switches the first brightness signal and the second brightness signal according to a video switching signal to output a combined brightness signal;
A multi-screen image quality improving circuit comprising a signal processing circuit for inputting the composite luminance signal and the image boundary signal to generate an image quality improving signal, wherein a boundary portion between the first image and the second image is generated by the image boundary signal. By not performing the image quality improvement processing in (1), it is possible to prevent the generation of an unnatural image that has conventionally occurred at the boundary portion and provide a more natural image.

The invention according to claim 3 of the present invention is the invention according to claim 2.
A multi-screen image quality improvement circuit in which the signal processing circuit in the multi-screen image quality improvement circuit described is replaced with a peaking circuit that generates an output luminance signal, or a speed modulation signal generation circuit that outputs a speed modulation signal. By preventing the peaking processing and the velocity modulation signal generation at the boundary between the first image and the second image, it is possible to prevent the generation of an unnatural image that has conventionally occurred at the boundary and provide a more natural image. You can

According to a fourth aspect of the present invention, there is provided a first video signal processing circuit for inputting a first video signal to generate a first luminance signal and a second video signal for inputting a second video signal. A second video signal processing circuit for generating a second brightness signal; and a first selector for switching the first brightness signal and the second brightness signal according to a video switching signal to output a composite brightness signal. A second selector which inputs the combined luminance signal, the frame level signal, and the frame signal and outputs a frame-added combined luminance signal obtained by replacing the combined luminance signal in the frame display period with the frame level signal;
A multi-screen image quality improving circuit including a signal processing circuit for inputting the frame-added combined luminance signal and the frame signal to generate an image quality improving signal, wherein a boundary portion between the first image and the second image is generated by the frame signal. By not performing the image quality improvement processing in, prevent the occurrence of unnatural images that had previously occurred at the boundary,
A more natural image can be provided.

The invention according to claim 5 of the present invention is the invention according to claim 4.
A multi-screen image quality improving circuit in which the signal processing circuit in the multi-screen image quality improving circuit described is replaced with a peaking circuit for generating an output luminance signal or a speed modulation signal generating circuit for outputting a speed modulation signal. Video and second
By not generating the velocity modulation signal at the boundary part of the image, it is possible to prevent the generation of an unnatural image that has conventionally occurred at the boundary part and provide a more natural image.

The invention according to claim 6 of the present invention is the invention according to claim 4.
In the described multi-screen image quality improvement circuit, input the frame signal,
A multi-screen image quality improvement circuit that includes a frame width enlargement circuit that generates an enlarged frame signal in which the horizontal or vertical width of the frame is widened, and uses the enlarged frame signal instead of the frame signal as an input signal of the signal processing circuit. By not performing image quality improvement processing at the boundary between the first image and the second image by the signal,
It is possible to prevent the occurrence of an unnatural image that has conventionally occurred at the boundary portion and provide a more natural image.

The invention according to claim 7 of the present invention is claim 6
A multi-screen image quality improving circuit in which the signal processing circuit in the multi-screen image quality improving circuit described is replaced with a peaking circuit that generates an output luminance signal, or a speed modulation signal generating circuit that outputs a speed modulation signal. By not generating the velocity modulation signal at the boundary portion between the first image and the second image, it is possible to prevent the generation of an unnatural image that has conventionally occurred at the boundary portion and provide a more natural image.

An example of an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is for claim 2 or 3 of the present invention, and FIG. 3 is for claim 4 or 5 of the present invention.
5 is a block diagram showing an embodiment of claim 6 or claim 7 of the present invention.

FIG. 2 is one of claims 2 and 3 of the present invention, FIG. 4 is one of claims 4 and 5 of the present invention, and FIG. 6 is one of claims 6 and 7 of the present invention. FIG. 9 is an operation waveform diagram illustrating an operation of the multi-screen image quality improving circuit according to the embodiment. The signals shown in FIGS. 1 and 2, FIGS. 3 and 4, and FIGS. 5 and 6 correspond to each other.

(Embodiment 1) In FIG. 1, 11 is
It is a first video signal processing circuit which inputs a first video signal and generates a first luminance signal. Reference numeral 12 is a second video signal processing circuit which receives the second video signal and generates a second luminance signal. Reference numeral 13 is a selector for switching the first luminance signal and the second luminance signal in accordance with the video switching signal and outputting the combined luminance signal. Reference numeral 14 is a peaking circuit for increasing the gain of the frequency band component to which the composite luminance signal and the video boundary signal are input and generating the output luminance signal. 1
Reference numeral 5 denotes a speed modulation signal generation circuit which inputs the combined luminance signal and the video boundary signal and outputs a speed modulation signal.

The operation of the multi-screen image quality improving circuit configured as described above will be described below with reference to FIGS. 1 and 2.

First, the first video signal processing circuit 11
The input video signal is subjected to luminance / color difference signal separation, synchronization processing, color demodulation, display size change processing, and the like, and a first video luminance signal is output. Next, the second video signal is input to the second video signal processing circuit 12 to perform luminance / color difference signal separation, synchronization processing,
Color demodulation, display size change processing, etc. are performed and a second luminance signal is output. Next, the first luminance signal, the second luminance signal, and the video switching signal are input to the selector 13, and the first luminance signal and the second luminance signal are switched according to the signal level of the video switching signal. Output the combined luminance signal.

Next, the peaking circuit 14 is supplied with a composite luminance signal and a video boundary signal for distinguishing a certain period before and after the level changing portion of the video switching signal from other periods, and the luminance signal changes its level at a certain frequency. At this time, by adding undershoot / overshoot to the signal level changing portion, the gain of a specific frequency band component is increased and an output luminance signal is generated, but the boundary portion between the first image and the frame, the frame display portion, the frame At the boundary between the second image and the second image, the operation of the peaking function as described above is stopped by the image boundary signal. Next, the combined luminance signal and the video boundary signal are input to the speed modulation signal generation circuit 15 to output a speed modulated signal that is the first-order differentiation of the combined brightness signal, but the boundary portion between the first video and the second video is output. In (1), the speed boundary signal is not generated by the video boundary signal.

As described above, by using the image boundary signal, it is possible to prevent an abnormal signal from being generated as a result of calculation between different image signals at the boundary portion between the first image and the second image, and It is controlled so that only the calculation of is performed.

(Second Embodiment) In FIG. 3, 31 is
It is a first video signal processing circuit which inputs a first video signal and generates a first luminance signal. Reference numeral 32 is a second video signal processing circuit which receives the second video signal and generates a second luminance signal. Reference numeral 33 is a first selector that switches the first luminance signal and the second luminance signal in accordance with the video switching signal and outputs a combined luminance signal. A second selector 34 receives the combined luminance signal, the frame level signal, and the frame signal and outputs the frame-added combined luminance signal obtained by replacing the combined luminance signal in the frame display period with the frame level signal. Reference numeral 35 is a peaking circuit for increasing the gain of the frequency band component to which the frame-added combined luminance signal and the frame signal are input and generating the output luminance signal. Reference numeral 36 denotes a speed modulation signal generation circuit that inputs the frame-added combined luminance signal and the frame signal and outputs a speed modulation signal.

The operation of the multi-screen image quality improving circuit configured as described above will be described below with reference to FIGS. 3 and 4.

First, the first video signal processing circuit 31
The input video signal is subjected to luminance / color difference signal separation, synchronization processing, color demodulation, display size change processing, and the like, and a first video luminance signal is output. Next, the second video signal is input to the second video signal processing circuit 32 to perform luminance / color difference signal separation, synchronization processing,
Color demodulation, display size change processing, etc. are performed and a second luminance signal is output. Next, the first brightness signal, the second brightness signal, and the video switching signal are input to the first selector 33, and the first brightness signal and the second brightness signal are input according to the signal level of the video switching signal. To output the composite luminance signal. Next, the combined luminance signal, the frame level signal, and the frame signal are input to the second selector 34, and the combined luminance signal in the frame display period is used as a frame level signal by the frame signal that distinguishes the frame display period from other periods. The frame-added combined luminance signal that has been changed to the luminance level set in is output.

Next, when the frame-added combined luminance signal and the frame signal are input to the peaking circuit 35 and the luminance signal changes in level at a certain frequency, an undershoot / overshoot is added to the signal level changing portion to specify the level. The gain of the frequency band component of is raised and the output luminance signal is generated,
At the boundary between the first image and the frame, the frame display part, and the boundary between the frame and the second image, the operation of the peaking function as described above is stopped by the frame signal. Next, the frame-added combined luminance signal and the frame signal are input to the speed modulation signal generation circuit 36 and the speed-modulated signal obtained by first-order differentiating the frame-added combined brightness signal is output. In the frame display portion and the boundary portion between the frame and the second image, the speed modulation signal is not generated by the frame signal.

As described above, in the multi-screen image quality improving circuit according to the fourth and fifth aspects, the frame signals are used to correlate each other for the peaking process and the generation of the velocity modulation signal at the boundary between the image and the frame. Among the abnormal signals generated as a result of calculating the non-existent signals, only the generation of an unnatural signal in the frame display portion is prevented.

(Embodiment 3) In FIG. 5, 51 is
It is a first video signal processing circuit which inputs a first video signal and generates a first luminance signal. Reference numeral 52 is a second video signal processing circuit that receives the second video signal and generates a second luminance signal. Reference numeral 53 is a first selector that switches the first luminance signal and the second luminance signal in accordance with the video switching signal and outputs a combined luminance signal. Reference numeral 54 denotes a second selector that inputs the combined luminance signal, the frame level signal, and the frame signal and outputs the frame-added combined luminance signal obtained by replacing the combined luminance signal in the frame display period with the frame level signal. Reference numeral 55 is a frame width enlarging circuit that inputs a frame signal and generates an enlarged frame signal in which the horizontal or vertical width of the frame is widened. Reference numeral 56 is a peaking circuit for increasing the gain of the frequency band component to which the frame-added combined luminance signal and the enlarged frame signal are input and generating an output luminance signal. Reference numeral 57 denotes a speed modulation signal generation circuit which inputs the frame-added combined luminance signal and the expansion frame signal and outputs a speed modulation signal.

The operation of the multi-screen image quality improving circuit configured as described above will be described below with reference to FIGS. 5 and 6.

First, the first video signal processing circuit 51
The input video signal is subjected to luminance / color difference signal separation, synchronization processing, color demodulation, display size change processing, and the like, and a first video luminance signal is output. Next, the second video signal is input to the second video signal processing circuit 52 to perform luminance / color difference signal separation, synchronization processing,
Color demodulation, display size change processing, etc. are performed and a second luminance signal is output. Next, the first brightness signal, the second brightness signal, and the video switching signal are input to the first selector 53, and the first brightness signal and the second brightness signal are input according to the signal level of the video switching signal. To output the composite luminance signal. Next, the combined luminance signal, the frame level signal, and the frame signal are input to the second selector 54, and the combined luminance signal in the frame display period is used as a frame level signal by the frame signal that distinguishes the frame display period from other periods. The frame-added combined luminance signal that has been changed to the luminance level set in is output.

Next, by inputting a frame signal to the frame width enlarging circuit 55 and without changing the actual frame display period, the expanded frame is expanded horizontally or vertically with respect to the frame display period by a certain period before and after. Generate a signal. Next, when the frame-added combined luminance signal and the enlarged frame signal are input to the peaking circuit 56 and the luminance signal changes in level at a certain frequency, by adding undershoot / overshoot to the signal level changing unit,
An output luminance signal is generated by increasing the gain of a specific frequency band component. However, at the boundary portion between the first image and the frame, the frame display portion, and the boundary portion between the frame and the second image, the expansion frame signal causes Stop the operation of the peaking function such as.

Next, the frame-added combined luminance signal and the enlarged frame signal are input to the speed modulation signal generation circuit 57, and the speed-modulated signal obtained by first-order differentiation of the frame-added combined brightness signal is output. At the border portion of the frame, the frame display portion, and the border portion of the frame and the second image, the speed modulation signal is not generated by the enlargement frame signal. In the multi-screen image quality improving circuit according to claim 6 or 7, the enlargement frame signal is used instead of the frame signal, and signals which are not correlated with each other for a peaking process and a velocity modulation signal generation at a boundary portion between the image and the frame. This prevents the generation of abnormal signals that occur as a result of computing one another.

[0034]

As described above, according to the present invention, when two or more images are combined and displayed on one image display device at the same time, the horizontal and vertical directions are improved for improving the image quality such as peaking processing and speed modulation signal generation. However, a more natural image can be provided by not performing the calculation of signals having no correlation with each other at the boundary between the image and the image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a multi-screen image quality improving circuit of the present invention.

FIG. 2 is an operation waveform diagram for explaining the operation of the circuit.

FIG. 3 is a block diagram showing an embodiment of a multi-screen image quality improving circuit of the present invention.

FIG. 4 is an operation waveform diagram for explaining the operation of the circuit.

FIG. 5 is a block diagram showing an embodiment of a multi-screen image quality improving circuit of the present invention.

FIG. 6 is an operation waveform diagram for explaining the operation of the circuit.

FIG. 7 is a block diagram of a conventional multi-screen image quality improving circuit.

FIG. 8 is an operation waveform diagram for explaining the operation of the circuit.

[Explanation of symbols]

 51 first video video signal processing circuit 52, second video video signal processing circuit 53, 14 selector 55 frame width expansion circuit 56 peaking circuit 57 speed modulation signal generation circuit

Claims (7)

[Claims] 1. A multi-screen image quality improving circuit, wherein when displaying a plurality of images on the image display means, different image signals for improving image quality are not calculated at the boundary between the images. 2. A first video signal processing circuit for inputting a first video signal to generate a first luminance signal, and a second video signal processing circuit for inputting a second video signal to generate a second luminance signal. A video signal processing circuit, a selector for switching the first luminance signal and the second luminance signal according to a video switching signal to output a synthetic luminance signal, and inputting the synthetic luminance signal and a video boundary signal. And a signal processing circuit for generating an image quality improving signal. 3. The signal processing circuit in the multi-screen image quality improving circuit according to claim 2, wherein the signal processing circuit is a peaking circuit for generating an output luminance signal or a speed modulation signal generation circuit for generating a speed modulation signal. Screen image quality improvement circuit. 4. A first video signal processing circuit for inputting a first video signal to generate a first luminance signal, and a second video signal processing circuit for inputting a second video signal to generate a second luminance signal. Video signal processing circuit, a first selector for switching the first luminance signal and the second luminance signal according to a video switching signal to output a combined luminance signal, the combined luminance signal and a frame level signal A second selector that outputs a frame-added combined luminance signal obtained by replacing the combined luminance signal in the frame display period with a frame level signal, and inputs the frame-added combined luminance signal and the frame signal. A multi-screen image quality improving circuit comprising a signal processing circuit for generating an image quality improving signal. 5. The signal processing circuit in the multi-screen image quality improving circuit according to claim 4, wherein the signal processing circuit is a peaking circuit for generating an output luminance signal or a speed modulation signal generation circuit for generating a speed modulation signal. Screen image quality improvement circuit. 6. The multi-screen image quality improving circuit according to claim 4, further comprising a frame width expanding circuit for inputting a frame signal and generating an expanded frame signal in which the horizontal or vertical width of the frame is expanded, and the input of the signal processing circuit. A multi-screen image quality improving circuit, wherein the enlargement frame signal is used as a signal. 7. The signal processing circuit in the multi-screen image quality improving circuit according to claim 6, wherein the signal processing circuit is a peaking circuit for generating an output luminance signal or a speed modulation signal generation circuit for generating a speed modulation signal. Screen image quality improvement circuit.