JPH0516787B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a television image synthesis circuit,
In particular, the present invention relates to a television image synthesis circuit that can synthesize a plurality of screens by switching video signals within an effective screen.

[Prior Art] Conventionally, in this type of television image composition circuit, as shown in FIG.
After selecting V ₁ to V _o , the first to mth multiplier circuits 1
5 and is keyed by a key signal. These key signals are signals generated by the key signal generation circuit 14 according to the horizontal pulse signal and the vertical pulse signal. The outputs of the first to m-th multiplier circuits 15 are added in an adder circuit 16 and synthesized on the screen, and then
A border is added to the border by a border adding circuit 6.

[Problems to be Solved by the Invention] Therefore, in the conventional television image synthesis circuit, multiplication circuits are required for the number of materials to be synthesized (m), and switching circuits are also required for the number of materials to be synthesized (m). ) is required, which has the drawback of increasing the size of the device.

[Means for Solving the Problems] To this end, the present invention provides a switching circuit that inputs a plurality of video signals and performs switching, and receives an output from the switching circuit and performs edge processing at the time of switching according to an edge signal. an edge processing circuit that receives the output of the edge processing circuit, adds a border to a switching position according to a border signal to form an output composite signal, and a material code that outputs a material code corresponding to the video signal. an output circuit; a switching control circuit that receives a material code from the material code output circuit and controls the switching circuit in accordance with a switching signal; and a switching control circuit that sends the switching signal to the switching control circuit in response to a horizontal pulse signal and a vertical pulse signal. and a switching signal generating circuit that outputs the edge signal to the edge processing circuit and outputs the border signal to the border adding circuit. This is what we provide.

[Example] Next, the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the television image synthesis circuit of the present invention. FIG. 2 is a detailed block diagram of the switching control circuit. 3 and 4 are explanatory diagrams of the same operation. FIG. 5 is a block diagram showing another embodiment of the television image synthesis circuit of the present invention. FIG. 6 is an explanatory diagram of the same operation.

First, change the screen to A, B, C, as shown in Figure 3.
A first embodiment of the television image synthesis circuit according to the present invention will be described with reference to FIGS. 1 to 4, taking as an example the case where the image is divided into four parts.

Reference numeral 4 denotes a switching signal generation circuit that generates switching signals, edge signals, and border signals in response to horizontal pulse signals and vertical pulse signals.

3 is a material code output circuit which outputs the material code of the video signal (material) selected at each position of A, B, C, D and information on the selected position within the vertical blanking period. . 2 is a switching control circuit connected to the switching signal generation circuit 4 and the material code output circuit 3, and has a memory 2A as shown in FIG. Then, using the position information input from the material code output circuit 3 as a write address, the material code similarly input from the material code output circuit 3 is written into the memory 2A within the vertical blanking period, and input from the switching signal generation circuit 4. The material code is read from the memory 2A within the effective screen using the switching signal as a read address and output. 1 is a switching circuit connected to the switching control circuit 2, which outputs the video signal V ₁
~ _Vo is input, and is appropriately selected and output according to the material code input from the switching control circuit 2. 5 is a switching circuit 1 and a switching signal generation circuit 4
The edge processing circuit connected to the switching signal generating circuit 4 determines whether or not switching has occurred in the horizontal direction within the effective screen using the edge signal given from the switching signal generating circuit 4, and determines whether or not switching has occurred in the horizontal direction within the effective screen. The edge portion of the video signal supplied from the switching circuit 1 is averaged at mutually adjacent sample points to limit the rise time of the waveform. Reference numeral 6 denotes a border adding circuit connected to the edge processing circuit 5 and the switching signal generating circuit 4, which adds a border to the border part of the screen according to the border signal input from the switching signal generating circuit 4 and outputs it as an output composite signal. ing.

In the switching signal generating circuit 4, when the horizontal pulse signal and the vertical pulse signal are input, RA ₁ =0,
RA ₀ = 0, B corresponds to RA ₁ = 0, RA ₀ = 1, C
RA ₁ = 1, RA ₀ = 0, corresponding to D
A 2-bit code of RA ₁ =1 and RA ₀ =1 is generated. Further, edge signals are generated at the boundaries in the horizontal direction, that is, the boundaries between A and B and the boundaries between C and D, as shown in FIG. 3'. Furthermore, 4
A border signal as shown in the hatched area in FIG. 3 is generated corresponding to the border of the material.

In the material code output circuit 3, A, B,
The material code of the video signal (material) selected at each position of C and D and the information of those selected positions (A
WA ₁ = 0, WA ₀ = 0, corresponding to the position of B, WA ₁ = 0, WA ₀ = 1, corresponding to the position of C, WA ₁ = 1, WA ₀ = 0, Corresponding to the position D, a 2-bit code WA ₁ =1, WA ₀ =1 is output to the switching control circuit 2 within the vertical blanking period.

In the switching control circuit 2, A, B, C, D on the screen
The material code is written to the memory 2A at the position (WA ₁ , WA ₀ ) as the write address within the vertical blanking period. This written data generates the switching signal (RA ₁ , RA ₀ ) corresponding to the position given from the switching signal generation circuit 4 in the memory 2A.
The address is read within the valid screen.

The read material code is output to the switching circuit 1, and the video signal (V ₁ ,
V ₂ ...V _o ) are selected and output to the edge processing circuit 5.

In the edge processing circuit 5, in order to suppress boundary ringing when switching is performed in the horizontal direction within the effective screen, two sample points (A ₁ and A 1 and
B ₁ ) data is averaged (A ₁ +B ₁ /2) to limit the rise time of the waveform.

This edge processing circuit 5 includes a border adding circuit 6.
This is not necessary if a border is always added to the boundary part.

The border adding circuit 6 receives the border signal from the switching signal generating circuit 4, adds a border to the boundary portion of the screen, and obtains an output composite signal.

In addition, here we have explained the case of 4-screen composition,
Even in the case of compositing more than one screen, this can be easily handled by increasing the write addresses and read addresses of the switching control circuit 2.

Furthermore, the structure and operation of a second embodiment of the television image synthesis circuit of the present invention will be explained with reference to FIGS. 5 and 6.

Reference numerals 7 to 10 designate first to fourth digital special effect devices, respectively, which are arranged with respect to the input terminals of the video signals V ₁ to V ₄ of the switching circuit 1 . The first to fourth digital special effect devices 7 to 10, together with the switching signal generation circuit 4, are used to change the screen size in response to a control signal. That is, when a control signal is given to the switching signal generation circuit 4 that determines the screen division size, and the four screens A to D are divided into the same size as shown in FIG. By applying a control signal to the four digital special effect devices 7 to 10 and controlling the size and position of the output, that is, the video signal, a simultaneous reduction effect of four screens can be obtained. Also, as shown in Fig. 6, while moving the dividing boundary in the direction of the arrow,
By changing the output of the fourth digital special effects devices 7 to 10, that is, the size and position of the video signal, it is possible to respond to changes in the size of the _V1 screen.

For other configurations and functions, see Figure 1~
Since it is the same as the first embodiment shown in FIG.
A detailed explanation thereof will be omitted.

[Effects of the Invention] As is clear from the above, the television image synthesis circuit of the present invention includes a switching circuit that inputs and switches a plurality of video signals, and a switching circuit that receives the output from the switching circuit and switches according to an edge signal. an edge processing circuit that performs edge processing at the time; a border addition circuit that receives the output of the edge processing circuit and adds a border to a switching position according to a border signal to form an output composite signal; and a material code corresponding to the video signal. a material code output circuit that outputs a material code; a switching control circuit that receives a material code from the material code output circuit and controls the switching circuit in accordance with a switching signal; On the other hand, since it is equipped with a switching signal generation circuit that outputs the switching signal, outputs the edge signal to the edge processing circuit, and outputs the border signal to the border adding circuit, It is possible to switch between a plurality of video signals and process the boundary portions, and it has the effect that screen composition can be performed without the need for a plurality of multiplier circuits as in the conventional method.

Furthermore, the present invention also allows the digital special effects device to be inserted into the input end of the switching circuit to link the screen division size and the screen reduction size, and has the effect of being able to synthesize the reduced screens.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the television image synthesis circuit of the present invention, FIG. 2 is a detailed block diagram of the switching control circuit, FIGS. 3 and 4 are explanatory diagrams of the same operation, and FIG. A block diagram showing another embodiment of the television image synthesis circuit of the present invention, FIG.
7 is a diagram explaining the same operation, and FIG. 7 is a block diagram showing a conventional example. 1...Switching circuit, 2...Switching control circuit, 3...
Material code output circuit, 4... switching signal generation circuit,
5... Edge processing circuit, 6... Border addition circuit.

Claims (1)

[Claims] 1. A switching circuit that inputs and switches multiple video signals, an edge processing circuit that receives the output from the switching circuit and performs edge processing during switching according to the edge signal, and a border that receives the output of the edge processing circuit. a border adding circuit that adds a border to a switching position in accordance with the signal to form an output composite signal; a material code output circuit that outputs a material code corresponding to the video signal; and a material code output circuit that receives the material code from the material code output circuit and performs switching. a switching control circuit that controls the switching circuit according to a signal; outputting the switching signal to the switching control circuit according to a horizontal pulse signal and a vertical pulse signal; and outputting the edge signal to the edge processing circuit; and a switching signal generating circuit for outputting the border signal to the border adding circuit.