JPH0358678A - Synthesizer for picture signal - Google Patents

Abstract

PURPOSE:To synthesize a natural picture onto a computer graphics picture by forming a synthesis key signal from a video signal of a natural picture to select the condition of the key signal with respect to the chromaticity of the natural picture. CONSTITUTION:Computer graphics signals Rc-Bc with a prescribed frequency are extracted from a RAM 12. Natural picture video signals Rn-Bn are digitized and written sequentially in a frame buffer 24 and a readout signal is supplied from a control circuit 13 in parallel with the write and the signals Rn-Bn are read synchronously with the signals Rc-Bc. A detection circuit 25 detects a period of the signals Rn-Bn reaching a specific chromaticity, outputs a detection signal Sk whose level is logical 1, the detected chromaticity is designated by a signal Si from the CPU 11 and the detection signal Sk is fed to a switch circuit 14 as a control signal. Thus, a natural picture is beautifully synthesized with respect to the computer graphics picture.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an image signal synthesis device.

[Summary of the Invention] The present invention is an image signal synthesis device, for example, by forming a key signal based on a video signal from a video camera, etc., into an image created by a computer graphics. This allows images to be viewed together.

[Prior art] A video signal from a video camera, etc. (hereinafter referred to as a natural image video signal) is added to a computer graphics image.
As a means of synthesizing and displaying natural images, there is an analog method called superimposition.

However, since video signals in computer graphics (hereinafter referred to as computer graphics signals) and natural image video signals generally have different synchronization frequencies, the computer graphics signals are written in a frame huffer (frame memory), This is read out in sync with the natural picture video Nobuo and used together.

Document 2: Japanese Unexamined Patent Publication No. 61-991.89 [Problems to be Solved by the Invention] However, when a natural image is combined with a computer graphics image, this may not be possible.

That is, when composing a computer graphics image and a natural image, a key signal for compositing is generated in the computer, a window is formed in the computer graphics image using this key signal, and Cut out the natural image using the key signal,
This cut out image of the natural painting is inserted into a window shaped like a computer graphics image, and the images are merged.

Therefore, when the shape of the window is a shape that can be easily formed on a computer, such as a circle or a rectangle, it is easy to combine images.

However, when you want the window to have an amorphous shape, for example, the shape of a person, especially when it is accompanied by movement, it is impossible to use the computer to manipulate the window's key signals to create such a shape. It is.

Therefore, it is not possible to display an image of an amorphous natural painting together with an image of Conbuque Graphics.

This invention attempts to solve these problems.

(Means for Solving the Problems) Therefore, in the present invention, a video memory for storing video data, a still picture memory for storing still picture data, and a still picture window from the still picture memory are provided. A display device comprising a display control means for inserting and displaying a moving image from the moving image memory in a region,
It has a color detection circuit that controls to display the still image in the corresponding section without displaying the specific color in the video image, and the specific color is determined by the settings included in the color detection circuit. This setting means is an image signal synthesizing device that can set an upper limit value and a lower limit value regarding color tone.

[Effect]

A key signal is formed from a natural image, and images are synthesized according to this key signal.

〔Example〕

In FIG. 1, (10) indicates a computer for computer graphics, (11) indicates its CPU, (
12) is a memory for image display, so-called V-RAM, (
13> is a memory control circuit. And C
The image data transformed in P U (11) is R
A M (12) is written to the address specified by CPU (11). At this time, a readout signal is supplied from the control circuit (13) to the RAM (12), and the video signals Re, Gc, and Bc of the three primary colors are repeatedly read out from the RAM (12) at a predetermined period. In other words, R A M (12) outputs a computer graphics signal Rc of a predetermined synchronized frequency.
=Bc is taken out.

Then, this (M bow R c - B c) is connected to the D/A converter (1
5) and is converted into an analog signal Rc=Bc,
This signal Rc''7Bc is supplied to the CRT display (16).

Therefore, in this state, the computer graphics signals Pc-Bc produced by the computer (10) are displayed on the display (16) as a combination computer graphics image.

In addition, natural image video signals (three primary color signals) RnOn, Bn
is supplied to the A/D converter (22) through the terminal (21), and is also supplied to the forming circuit (23), where various signals synchronized with the signal Rn=Bn are outputted. , of which the clock is Konharta (
22) and the signal Rn=Bn is converted into a digital signal.

Then, this signal Rn=Bn is a frame huffer (24
), a write signal is also supplied from the frame buffer (23) to the frame buffer (24), and the signal Rn=Bn is sequentially written to the frame buffer (24). In addition, in parallel with this writing, a read signal is sent from the control circuit (13) to the frame Hanfa (
24), and the signal Rn-Bn is read out from the frame buffer (24) in synchronization with the signal Rc-Bc.

Then, this signal Rn=Bn is sent to the switch circuit (14)
is supplied to Therefore, the switch circuit (14)
Contrary to the diagram, when connected to a frame huffer (24HI.!J), the natural image video signal Rn~Bn
will be displayed on the display (16) as a natural image.

Furthermore, at this time, the signal Rn=Bn from the frame buffer (24) is supplied to the color detection circuit H (25).

The details of this detection circuit (25) will be described later, but
This detection circuit (25) detects 3υj with signal Rn=Bn.
When a period (section) has a specific chromaticity, that period is detected and a detection signal Sk that becomes "'1" is output. However, at this time, the detected chromaticity is C P
specified by the signal Si from tJ (11). Further, the detection signal Sk is supplied to the sinch circuit (14) as its control signal, and the sinch circuit (14)
- When it is '1', it is connected to the RAM (12) side as shown in the figure.

In such a configuration, for example, the natural image video signal R
It is assumed that n=Bn is a signal obtained when a natural image with a white pole in front of a blue hunk is photographed, and that the signal 31 specifies the blue color of the hunk.

Then, the detection signal Sk is the blue part UJ of the cansock.
I) becomes ′゜1゛, and the white ball part becomes ゛0”.
'become. Since the switch circuit (14) is controlled by such a signal Sk, the signals Rc to Bc are connected to the conharter (14) in the blue part of the photographed natural image.
5), and in the white ball part, the signal Rn-
Bn is supplied to the converter (l5). therefore,
The display (16) displays an image in which a computer graphics image based on the signal Rc=Bc is combined with an image of a white ball based on the signals Rn to Bn.

Thus, according to the present invention, a natural image can be displayed in combination with a computer graphics image.

In this case, especially according to the present invention, since the key signal Sk for synthesis is formed from the video signal Rn=Bn of the natural image, there is no restriction on the shape of the window when synthesizing the signal. , the shape of an image in a natural image can be used as a window for synthesis. Moreover, since the shape of the window or the conditions of the key signal Sk can be selected by the signal Si with respect to the chromaticity of the natural image, it is possible to neatly synthesize the natural image with the computer graphics image.

Furthermore, since signal processing is performed by hardware, it can be processed in real time at high speed.

FIG. 2 shows an example of a color detection circuit (25).

However, in this example, the signal Rn (and Gn, Bn
) is from "O" to r 255 J, as shown in Figure 3.
Assume that there are 256 gradations.

Then, the signal Rn is supplied to the level comparator circuit (5RU), and the -I two limit value R
ll is supplied to the comparator circuit (5170) as a reference value,
From the comparison circuit (5RIJ), R
When n>Rll, Rx="O" When Rn≦R11, Rx="1" A signal Rx is extracted. Further, the signal Rn is supplied to the level comparator circuit (5RL), and the L/
'; Star (6RL) Lower limit {aR L Power is supplied as a reference value to the comparison circuit (5Rl.);
As shown in FIG. 3, a signal Ry is extracted from the signal RL (Ry = "1" when Rn≧RL, and Ry = "0" when Rn<Rl). Note that the limit value RLI,
RL is the signal S1 related to the signal Rn, which is?
Register (6RU), (6
RI, ).

Then, the signals Rx and Ry are supplied to the AND circuit (7R), and as shown in Fig. 3, when RL≦Rn≦RU, Rk-“1” and other cases
A signal Rk such that Rk='0'° is taken out, and this signal Rk is supplied to an AND circuit (8).

The same applies to the signals Gn and Bn, (5GU
), (5GL), (5BU), (5B+,
) are level comparison circuits, (6GU), (6GI,)
, (68LI), (6BL) are registers, GU,
GL, 80, Bl■ are the upper and lower limit values for the signals Gn and Bn. And the AND circuit (7G),
From (7B), when Gl, ≦Gn≦GU, Gk-“
1"Other times Gk="O"' When B1, ≦Bn≦BU Bk-"1"Other times
Signals Gk and Bk where Bk is "0" are taken out, and these signals Gk,
Bk is supplied to an AND circuit (8).

Therefore, the AND circuit (8) outputs a signal that becomes ゜'1゛ only when the level of the signal Rn~11Bn is within the range of RL≦Rn≦Rtl GI,≦On≦GLI BL≦Bn≦BU , that is, the key signal Sk is extracted.

In the above description, for example, one set of limit values RU and RL is set for the signal Rn, but two or more sets of limit values may be set. In that case, each set of limit values may be used as a window key signal for a different computer graphics signal.

[Effects of the Invention] According to the present invention, since the key signal Sk for compositing is generated from the video signals Rn to Bn of natural images, there is no restriction on the shape of the window when composing them. , the shape of an image in a natural image can be used as a window for synthesis. Moreover, the shape of the window or the condition of the key signal Sk can be selected by the signal St with respect to the chromaticity of the natural image.
Natural images can be clearly compared to computer graphics images.

Furthermore, since signal processing is performed by hardware, it can be processed in real time at high speed.

[Brief explanation of drawings]

FIG. 1 is a connection diagram of an example of the present invention, FIG. 2 is a connection diagram of a part thereof, and FIG. 3 is a diagram for explaining the same. (10) is a computer, (12) is a memory for image display, (24) is a frame buffer, and (25) is a color detection circuit. Agent Hidemori Matsukuma

Claims (1)

[Claims] A video memory for storing video data, a still image memory for storing still image data, and a video from the video memory within a window area of the still video from the still image memory. A display device having a display control means for displaying an image by inserting it therein, a color detection circuit that controls the display to display the still image in the corresponding section without displaying a specific color in the moving image. The specific color is set by a setting means included in the color detection circuit, and the setting means is capable of setting an upper limit value and a lower limit value regarding color tone.