JPH11305746A - Processor and method for video signal processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to converts the frequency of a video signal with simple constitution. SOLUTION: This processor is equipped with a synchronous processing and matrix circuit 9 which generates a video signal of the VGA(video graphic array) system from a video signal of the NTSC or PAL system, a timing generating circuit 10 which generates a timing signal for masking a specific part of the video signal of the NTSC or PAL system according to the vertical synchronizing signal of the video signal of the VGA system, mask processing circuits 7 and 8 which performs mask processing according to the timing signal, and a VGA monitor which displays images of the video signal of the VGA system after the mask processing. Consequently, the timing signal for the mask processing can be generated with the simple constitution without timing the mask processing and signal processing to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing apparatus and a video signal processing apparatus for performing signal processing for displaying a video signal (NTSC / PAL) on a monitor of a personal computer (hereinafter referred to as "PC"). Regarding the processing method.

[0002]

2. Description of the Related Art Conventionally, a camera-integrated 8 mm video tape recorder (hereinafter, referred to as a camera-integrated 8 mm VTR) is composed of a camera unit and a VTR unit, and an image of a subject captured by the camera unit. Is converted into an electric signal, and is subjected to predetermined signal processing by a VTR unit, and then magnetically recorded on a magnetic tape. And
The video signal recorded on the magnetic tape by the VTR section is reproduced and supplied to the monitor, and the image of the video signal is displayed.

A video signal received by a television receiver is directly displayed as an image of the video signal by the television receiver, or a video signal received by a tuner section of a video tape recorder is supplied to a monitor, The image of the signal was displayed.

Here, in order to display the above-mentioned video signal on a monitor for a personal computer, the NTSC system or the PA
VGA (Video Graphics Array), which is a standard for resolution displayed on a personal computer from the L system.
y) A conversion process to the system must be performed. In this conversion process, the horizontal frequency is converted by changing the timing of writing and reading to and from the memory, and at the same time, the luminance signal Y and the
(Red), G (green), and B (blue) signals.

As described above, the NTSC system or PAL
When converting from the VGA system to the VGA system for a monitor for a personal computer, the horizontal frequency is doubled (from 15 KHz to 31 KHz).
Hz). Specifically, the horizontal frequency double conversion processing of the horizontal video signal and the horizontal synchronization signal is performed by using the input NTSC or PAL video synchronization signal and the timing signal dedicated to the conversion processing circuit. In this conversion processing system using a general-purpose dedicated IC (integrated circuit) or the like, the processing timing can be varied by a control signal supplied from the outside, and detailed settings can be made.

[0006]

However, the input N
Since the broadcast data and the VTR head switching position data of the video signal of the TSC system or the PAL system are included, the image on the monitor is disturbed when converted to the VGA system as it is. Therefore, in the above-described conventional conversion processing, in addition to the above-described conversion processing, processing for masking broadcast data and VTR head switching position data of the input NTSC or PAL video signal is further required. is there. In order to perform such a mask process, it is necessary that the above-described IC dedicated to control timing drives the mask process. Therefore, it is necessary to set the timing processing between ICs while synchronizing the horizontal frequency doubling conversion processing and the mask timing processing, so that the control signal is complicated, and an apparatus for performing such control is expensive. There was an inconvenience of becoming.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a video signal processing apparatus and a video signal processing method capable of performing a video signal frequency conversion process with a simple configuration. .

[0008]

SUMMARY OF THE INVENTION In order to solve this problem, a video signal processing apparatus according to the present invention writes or reads a first video signal supplied from a video signal supply source to a storage unit at different timings. And generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal. Timing generating means for performing, mask processing means for masking a predetermined portion of the first video signal based on the timing signal, and supplying the first video signal after the mask processing to the signal processing means; Display means for displaying an image of the second video signal after the mask processing generated by the signal processing means.

Further, according to the video signal processing method of the present invention, the first video signal supplied from the video signal supply source is written to or read from the storage unit at different timings, thereby converting the second video signal. A signal processing step of generating; a timing generating step of generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal; A mask processing step of masking a predetermined portion of the first video signal based on the first video signal, and then subjecting the masked first video signal to signal processing in the signal processing step; Displaying the image of the second video signal after the mask processing, and displaying the second video signal subjected to the mask processing. Those were Unishi.

According to the video signal processing device of the present invention, the following operations are performed. Data that is not desired to be displayed on the display means is provided in a predetermined horizontal period at the beginning of one vertical period of the first video signal. Such data is unnecessary data when it is displayed on the monitor of the second video signal, and if it is displayed on the monitor of the second video signal without deleting it, flickering appears on the top and bottom of the screen. It is necessary to mask these data by mask processing means.

The first video signal is supplied to signal processing means, which generates and outputs a horizontal synchronizing signal and a vertical synchronizing signal based on the luminance signal of the first video signal. The vertical synchronizing signal is supplied to timing generating means, and the timing generating means generates a timing signal for mask processing based on the vertical synchronizing signal and supplies the timing signal to the mask processing means.

The timing generating means generates a first timing signal having a pulse width of a predetermined period from the rise of the vertical synchronization signal, and a second timing signal rising after a predetermined horizontal period from the rise of the first timing signal. .

The timing generation means generates a mask signal having a pulse width of a predetermined period before and after the vertical synchronization signal and a horizontal period including data to be masked, and supplies the mask signal to the mask processing means. I do. The timing generation means calculates a logical sum of the first timing signal and the second timing signal to generate a mask signal.

[0014] The mask processing means is configured to perform the first processing based on the mask signal.
Mask processing is performed on the luminance signal and the color signal of the video signal to generate a mask video luminance signal and a mask video color signal and supply them to the signal processing means. The mask processing means outputs the black level only during the period of the pulse width specified by the mask signal, and outputs the luminance signal and the color signal of the first video signal as they are during the period not specified by the mask signal.

The mask image luminance signal and the mask image color signal which have been subjected to the mask processing as described above are supplied to the signal processing means. The signal processing means changes the horizontal frequency to a predetermined multiple by changing the timing of writing and reading to and from the storage unit, and at the same time, performs R (red), G (green), and B (blue) from the luminance signal and the chrominance signal by matrix processing.
The signals are converted into signals to generate video R, G, B signals and supplied to the display means. Thereby, a conversion process for converting the first video signal into the second video signal can be performed. The display means of the second video signal system displays an image of the second video signal which has been subjected to the mask processing.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. The video signal processing apparatus according to the present embodiment converts a video signal from an NTSC system or a PAL system to a VGA (Video) for a monitor for a personal computer.
Immediately before the horizontal frequency of the video signal is converted to a Graphics Array (Registered Graphics) system to generate R, G, and B video signals, timing control of mask processing is performed based on the vertical synchronization signal.

FIG. 1 is a block diagram showing a configuration of a video signal processing device according to the present embodiment. In FIG. 1, a video signal processing apparatus according to the present embodiment includes an input terminal 1 to which a composite video signal CS is supplied, an input terminal 2 to which a luminance signal is supplied, an input terminal 3 to which a chrominance signal is supplied, A Y / C separation circuit 4 for separating the composite video signal CS into a luminance signal Y and a chrominance signal C; a luminance signal Y separated by the Y / C separation circuit 4 and supplied to the movable contact b; Switch 5 for selectively switching the luminance signal Y supplied to the movable contact c and outputting it to the fixed contact a
And the color signal C separated by the Y / C separation circuit 4 and supplied to the movable contact b, and the color signal C inputted to the input terminal 3 and moved to the movable contact c.
And a switch 6 for selectively switching the color signal C supplied to the fixed contact a and outputting the same to the fixed contact a.

The masking of the video signal can be performed by inputting the composite video signal CS or inputting the luminance signal Y and the chrominance signal C. Therefore, the input terminal 1 to which the composite video signal CS can be input and the luminance Input terminals 2 and 3 to which a signal Y and a color signal C can be input are provided, and these are switched by switches 5 and 6.

The composite video signal CS or the luminance signal Y and the color signal C supplied to the input terminal 1 or the input terminals 2 and 3 of the video signal recording / reproducing apparatus are combined with a camera-integrated 8 mm VTR or a television receiver. Is supplied from a tuner.

The camera-integrated 8-mm VTR is composed of a camera unit and a VTR unit (not shown). The image of the subject captured by the camera unit is converted into an electric signal.
After predetermined signal processing is performed by the VTR unit, the signal is magnetically recorded on a magnetic tape.

The video signal processing apparatus according to the present embodiment has a mask processing circuit 7 for masking broadcast data and VTR head switching position data of the input NTSC or PAL luminance signal Y.
And a mask processing circuit 8 for masking broadcast data and VTR head switching position data of the input NTSC or PAL color signal C.

The video signal processing apparatus according to the embodiment is a conversion process from the NTSC system or the PAL system to the VGA system which is a standard of resolution for monitor display on a personal computer. To double the horizontal frequency (15KHz → 3
1KHz), and at the same time, from the luminance signal Y and the chrominance signal C by matrix processing, R (red), G (green),
A synchronization processing and matrix circuit 9 for converting into a B (blue) signal, and a timing signal for mask processing in mask processing circuits 7 and 8 are generated using a vertical synchronization signal (VSYNC) generated by synchronization processing and matrix circuit 9. And a timing generation circuit 10 for performing the operation. In addition,
The VGA system is a standard of resolution displayed on a monitor of a personal computer, and can display 16 out of 260,000 colors at 640 × 480 dots. , And VGA resolution.

The video signal processing apparatus of the present embodiment configured as described above operates as follows. This will be described with reference to the above-described block diagram of FIG. 1 and the timing chart of FIG. 2 showing the operation of timing creation and mask processing.

When the composite video signal CS is supplied to the input terminal 1, the composite video signal CS is supplied to a Y / C separation circuit 4, and the Y / C separation circuit 4 converts the composite video signal CS into a luminance signal Y and a chrominance signal. C. Y /
The luminance signal Y separated by the C separation circuit 4 is
Is supplied to the movable contact b. The color signal C separated by the Y / C separation circuit 4 is supplied to the movable contact b of the switch 6. At this time, the fixed contacts a of the switches 5 and 6 are respectively connected to the movable contacts b. Accordingly, the luminance signal Y and the chrominance signal C separated by the Y / C separation circuit 4 are supplied to the fixed contacts a of the switches 5 and 6.

When the luminance signal Y is supplied to the input terminal 2 and the chrominance signal C is supplied to the input terminal 3, the input terminal 2
Is supplied to the movable contact c of the switch 5, and the color signal C input to the input terminal 3 is supplied to the switch 6.
To the movable contact c. At this time, the fixed contacts a of the switches 5 and 6 are respectively connected to the movable contacts c. As a result, the luminance signal Y and the chrominance signal C supplied to the input terminals 2 and 3 are supplied to the fixed contacts a of the switches 5 and 6.

FIG. 2A shows an input video luminance signal Y, and FIG. 2B shows an input video color signal C.
V) is provided with broadcast data 21 such as a text broadcast for tuner reception in a predetermined horizontal period at the head of the VTR, and a VTR during a predetermined horizontal period at the rear end of one vertical period (1V). Head switching position data 22 is provided. Such data 21, 22
Are unnecessary data when displayed on a VGA monitor, and when displayed on a VGA monitor without deleting them, flickers appear at the top and bottom of the screen. 8, mask processing is required.

Here, the luminance signal Y supplied to the fixed contact a of the switch 5 is supplied to the synchronization processing and matrix circuit 9, and the synchronization processing and matrix circuit 9 performs the horizontal synchronization signal H based on the luminance signal Y. SYNC and a vertical synchronization signal VSYNC are generated and output. The vertical synchronizing signal V SYNC is supplied to the timing generation circuit 10.
The timing generation circuit 10 generates a timing signal for mask processing based on the vertical synchronization signal VSYNC, and supplies it to the mask processing circuits 7 and 8.

Specifically, the timing creation circuit 10
A timing signal 1 shown in FIG. 2D having a pulse width of a predetermined period from the rise of the vertical synchronization signal V shown in FIG. 2C;
A timing signal 2 shown in FIG. 2E which rises after a predetermined horizontal period from the rising of the timing signal 1 is generated.
Here, the timing signal 1 is, for example, the vertical synchronization signal V
Is latched for a predetermined horizontal period including the data 21 using the horizontal synchronizing signal H as a clock. Also, the timing signal 2
Is latched after counting a predetermined number of horizontal synchronization signals H from the rising signal of the timing signal 1, for example.
It is generated by latching only a predetermined horizontal period including the data 22 using the horizontal synchronization signal H as a clock.

The timing generation circuit 10 has a pulse width of a horizontal period that is a predetermined period before and after the vertical synchronization signal V and includes the data 21 and the data 22.
The mask signal (1 + 2) shown in FIG. 2F is generated and supplied to the mask processing circuits 7 and 8. Specifically, for example, the timing creation circuit 10 generates a mask signal (1 + 2) by calculating a logical sum of the timing signal 1 and the timing signal 2 by using an OR gate.

The mask processing circuits 7 and 8 output a mask signal (1
+2) to perform a mask process on the luminance signal Y and the color signal C to generate a mask image luminance signal Y ′ shown in FIG. 2G and a mask image color signal C ′ shown in FIG. To supply. Specifically, the mask processing circuits 7 and 8 output, for example, a mask signal (1
The black level is output by switching on only during the high level H of (+2), and the luminance signal Y and the chrominance signal C are output as they are by switching off during the low level L of the mask signal (1 + 2).

The mask image luminance signal Y ′ and the mask image color signal C ′ that have been subjected to the mask processing are supplied to the synchronization processing and matrix circuit 9. The synchronization and matrix circuit 9 changes the horizontal frequency by 2 by changing the timing of writing and reading to and from the memory.
At the same time, the luminance signal Y and the chrominance signal C are converted into R signals by matrix processing.
(Red), G (green), and B (blue) signals,
G and B signals are generated and supplied to a VGA monitor. As a result, it is possible to perform a conversion process from the NTSC system or the PAL system to the VGA system which is a standard of resolution for monitor display on a personal computer. In the case of the VGA type monitor, for example, the horizontal scanning lines 30 are located at the upper and lower portions of the screen, not in the display area of the screen.
About this signal is masked, and a high-quality image free from flickering at the top and bottom of the screen can be obtained. Note that the horizontal synchronization signal HSYNC and the vertical synchronization signal VSYNC generated by the synchronization processing and matrix circuit 9 are supplied to other circuits.

As described above, in order to display a video signal on a monitor of a personal computer, an NTSC system or a PAL system is used.
A mask processing circuit is provided to perform mask processing immediately before double horizontal frequency conversion when converting a video signal of the VGA system into R, G, B signals of the VGA system. In this case, since the timing of the mask processing matches the timing of the vertical synchronizing signal, there is no need to supply other complicated timing signals from the outside, and further, using a general-purpose IC, for example, a simple latch circuit Timing circuit 10 with gate and gate circuit
Can be configured.

Since the video signal is managed according to the video standard, if the accuracy of the above-described timing generation circuit 10 can conform to the target specification, it can be simply configured using a general-purpose IC as described above. be able to. Further, as described above, since the synchronization timing is also synchronized with the video signal without using a dedicated IC, the timing can be easily managed.

The video signal processing apparatus of the present embodiment writes or reads the first video signal supplied from the video signal supply source to the storage unit at different timings, thereby converting the second video signal. Synchronization processing and matrix circuit 9 as signal processing means for generating, and timing generation means for generating a timing signal for masking a predetermined portion of the first video signal based on the synchronization signal of the second video signal A timing creation circuit 10 as
Mask processing circuits 7 and 8 as mask processing means for masking a predetermined portion of the first video signal based on the timing signal and supplying the first video signal after the mask processing to the signal processing means; Display means for displaying an image of the second video signal after the mask processing generated by the means;
Therefore, a timing signal for masking a predetermined portion of the first video signal from the synchronization signal of the second video signal with a simple configuration can be obtained without adjusting the timing of the mask processing and the signal processing. It can be generated and the quality of the image displayed by the display means can be improved.

Further, in the video signal processing apparatus of the present embodiment, the timing signal generated by the timing generation circuit 10 as the timing generation means
Since the predetermined horizontal period is masked for each of the leading and trailing ends of one vertical period of the first video signal, the timing of setting the masking period can be easily determined from the synchronization signal of the second video signal. This makes it possible to delete unnecessary data that is not desired to be displayed on the screen when displaying it on the display means, and to prevent flickering from appearing on the upper and lower sides of the screen with simple timing creation.

Further, in the video signal processing apparatus according to the present embodiment, the mask processing by the mask processing circuits 7 and 8 as the mask processing means in the above-described operation is performed by setting the first video signal to black during the period designated by the timing signal. Since the level is set to the level, it is easy to simply switch to the black level at the timing based on the synchronization signal of the second video signal without providing a dedicated circuit for adjusting the timing of the signal processing and the timing of the mask processing. Mask processing can be performed by timing and switching processing.

In the video signal processing apparatus according to the present embodiment, in the above description, the first video signal is an NTSC or PAL video signal, and the second video signal is a VG video signal.
A video signal of the A system, and the synchronous processing and matrix circuit 9 as a signal processing means performs reading at twice the writing timing, so that the video signal of the NTSC system or the PAL system is converted into a VGA signal.
It is possible to perform double horizontal frequency conversion when converting into R, G, B signals of the system, and display a video signal on a monitor of a personal computer.

In the video signal processing method according to the present embodiment, the first video signal supplied from the video signal supply source is written to or read from the storage section at different timings, thereby performing the second video signal processing. A signal processing step of generating a signal; a timing generating step of generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal;
A mask processing step of masking a predetermined portion of the first video signal based on the timing signal, and then subjecting the masked first video signal to signal processing in the signal processing step; And a display step of displaying the image of the second video signal after the mask processing. The timing between the mask processing step and the signal processing step is displayed. A timing signal for masking a predetermined portion of the first video signal can be generated from the synchronization signal of the second video signal by a simple process without the need for a step of adjusting the timing of the second video signal. Accordingly, the processing time can be reduced, and the quality of the image displayed in the display step can be improved.

In the video signal processing method according to the present embodiment, in the above description, the timing signal generated in the timing generating step is generated based on a vertical synchronization signal of the second video signal, and Since the mask processing is performed for the predetermined horizontal period of each of the leading end portion and the trailing end portion of one vertical period of the signal, the timing of setting the masking period can be easily determined from the synchronization signal of the second video signal. Thus, it is possible to prevent unnecessary data that is not desired to be displayed on the screen at the time of display in the display step from being deleted and flickering to appear on the upper and lower sides of the screen by a simple timing creation process.

In the video signal processing method according to the present embodiment, the mask processing in the mask processing step is such that the first video signal is set to a black level by switching during a period specified by the timing signal. Therefore, a simple timing and switching process can be performed simply by switching to the black level at a timing based on the synchronization signal of the second video signal without providing a dedicated processing step for adjusting the timing of the signal processing and the timing of the mask processing. Can perform a masking process. In the present embodiment described above, the NTSC system or the PSC
Although only the case of double horizontal frequency conversion when converting an AL video signal to a VGA R, G, B signal has been described, a high vision video signal is converted to a VGA R, G, B signal. It may be applied when performing horizontal frequency conversion by a predetermined number of times.

[0041]

According to the video signal processing apparatus of the present invention, the first video signal supplied from the video signal supply source is written to or read from the storage unit at different timings, thereby converting the second video signal. Signal processing means for generating, a timing generation means for generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal, Mask processing means for masking a predetermined portion of the first video signal based on the first video signal and supplying the first video signal after the mask processing to the signal processing means; and a post-mask processing generated by the signal processing means. Display means for displaying the image of the second video signal of the second video signal without adjusting the timing between the mask processing and the signal processing. Al can generate a timing signal for masking a predetermined portion of the simple first video signal in the configuration, an effect that it is possible to improve the quality of the image displayed by the display means.

Further, in the video signal processing apparatus of the present invention, the timing signal generated by the timing generating means may include a predetermined horizontal signal at a leading end and a trailing end of one vertical period of the first video signal. Since the period is masked, it is possible to easily determine the timing of setting the mask period from the synchronization signal of the second video signal, and therefore, it is not desired to display the timing on the screen when displaying on the display means. It is possible to prevent unnecessary data from being deleted and flickering from appearing above and below the screen with simple timing creation.

Further, in the video signal processing apparatus of the present invention, in the above, the mask processing by the mask processing means sets the first video signal to a black level during a period designated by the timing signal. The mask processing can be performed by simple timing and switching processing by simply switching to the black level at a timing based on the synchronization signal of the second video signal without providing a dedicated circuit for adjusting the timing of signal processing and the timing of mask processing. Is achieved.

Further, in the video signal processing apparatus according to the present invention, in the above, the first video signal may be in the NTSC format or in the P format.
AL video signal, and the second video signal is VG
A video signal of the A system, and the signal processing means performs reading at twice the writing timing, so that the video signal of the NTSC system or the PAL system is converted into the R, G, B signal of the VGA system. 2 when converting to
The double horizontal frequency conversion can be performed, and the video signal can be displayed on the monitor of the personal computer.

Further, according to the video signal processing method of the present invention, the first video signal supplied from the video signal supply source is written to or read from the storage unit at different timings, thereby converting the second video signal. A signal processing step of generating; a timing generating step of generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal; A mask processing step of masking a predetermined portion of the first video signal based on the first video signal, and then subjecting the masked first video signal to signal processing in the signal processing step; Displaying the image of the second video signal after the mask processing, and displaying the second video signal subjected to the mask processing. Therefore, a step of adjusting the timing between the mask processing step and the signal processing step is not required, and the predetermined portion of the first video signal is masked by a simple process from the synchronization signal of the second video signal. Can be generated, and the simplification of the processing can shorten the processing time and improve the quality of the image displayed in the display step.

In the video signal processing method according to the present invention, the timing signal generated in the timing generating step is generated based on a vertical synchronization signal of the second video signal. Since the mask processing is performed for the predetermined horizontal period of each of the leading end portion and the trailing end portion of one vertical period of the signal, the timing of setting the masking period can be easily determined from the synchronization signal of the second video signal. Thus, there is an effect that unnecessary data that is not desired to be displayed on the screen when displayed in the display step is deleted and flickering appears on the upper and lower sides of the screen can be prevented by a simple timing creation process.

In the video signal processing method according to the present invention, the mask processing in the mask processing step is such that the first video signal is set to a black level by switching during a period designated by the timing signal. Therefore, without providing a dedicated processing step for adjusting the timing of signal processing and the timing of mask processing, simple timing and switching can be achieved simply by switching to the black level at the timing based on the synchronization signal of the second video signal. There is an effect that mask processing can be performed in the processing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a video signal processing device according to an embodiment of the present invention.

FIGS. 2A and 2B are time charts showing timing generation and mask processing operations according to the embodiment of the present invention. FIG. 2A is an input video luminance signal (Y), FIG. 2B is an input video color signal (C), and FIG. 2D is a timing signal 1, FIG. 2E is a timing signal 2, FIG. 2F is a mask signal (1 + 2), FIG. 2G is a mask video luminance signal (Y '), and FIG. 2H is a mask video color signal (V). C ′) are shown.

[Explanation of symbols]

1 ‥‥ input terminal, 2 ‥‥ input terminal, 3 ‥‥ input terminal, 4
{Y / C separation circuit, 5 switch, 6 switch, 7 mask processing circuit, 8 mask processing circuit, 9}
{Synchronization processing and matrix circuit, 10} Timing creation circuit, 21} Broadcast data, 22 {VTR switching position data, Y} Luminance signal, C}
Color signal, HSYNC horizontal sync signal, CS composite video signal, VSYNC vertical sync signal,
R, G, B ‥‥ Video R, G, B signals

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 9/64 H04N 9/64 P

Claims (7)

[Claims] 1. A signal processing means for generating a second video signal by writing or reading a first video signal supplied from a video signal supply source to a storage unit at different timings, and generating a second video signal. Timing generating means for generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal; and the first video signal based on the timing signal Mask processing means for masking a predetermined portion of the first image signal and supplying the first video signal after the mask processing to the signal processing means;
And a display means for displaying an image of the video signal. 2. The video signal processing device according to claim 1, wherein the timing signal generated by the timing generation means is a predetermined horizontal period of a leading portion and a trailing portion of one vertical period of the first video signal. A video signal processing apparatus characterized in that a mask processing is performed on the image signal. 3. The video signal processing device according to claim 1, wherein the mask processing by the mask processing means sets the first video signal to a black level during a period specified by the timing signal. Characteristic video signal processing device. 4. The video signal processing device according to claim 1, wherein the first video signal is an NTSC or PAL video signal, the second video signal is a VGA video signal, A video signal processing device, wherein the signal processing means performs reading at twice the timing of the writing timing. 5. A signal processing step of generating a second video signal by writing or reading a first video signal supplied from a video signal supply source to a storage unit at different timings, and generating a second video signal; A timing generation step of generating a timing signal for masking a predetermined portion of the first video signal based on a synchronization signal of the second video signal; and a first video signal based on the timing signal. A mask processing step of performing a signal processing on the first video signal after the mask processing by the signal processing step after mask processing of a predetermined portion of the second video signal; and a second video signal after the mask processing generated by the signal processing step And a display step of displaying the image of (b), wherein the second video signal subjected to the mask processing is displayed. No. treatment method. 6. The video signal processing method according to claim 5, wherein the timing signal generated in the timing generation step is generated based on a vertical synchronization signal of the second video signal, and the first video signal is generated. 3. A video signal processing method, wherein mask processing is performed for a predetermined horizontal period of each of a leading end portion and a trailing end portion of one vertical period. 7. The video signal processing method according to claim 5, wherein the mask processing in the mask processing step is to switch the first video signal to a black level by switching during a period specified by the timing signal. A video signal processing method, characterized in that: