JP2570094B2 - Image special effect circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image special effect circuit, and more particularly to an image effect (hereinafter referred to as "decay effect") capable of displaying an afterimage of a graphic image when the image moves on a screen. The present invention relates to an image special effect circuit that can be realized.

[0002]

2. Description of the Related Art In general, as a device for producing a special effect of an image, DVE (Digital Video Eff) is used.
is known. The DVE is a device that enlarges, reduces, moves, rotates, etc., an input video.
For example, if the image 31 of “ABC” shown in FIG. When the “ABC” graphic in the image 32 is moved to the lower left of the screen, the image 3
It looks like 3.

[0003] Here, all the images that are being moved from the position of the graphic "ABC" in the image 32 to the position of the graphic "ABC" in the image 33 are stored, and the graphic is moved to the lower left of the screen while storing the image. Then, an image 34 is obtained. That is, in the image 34, a decay effect is obtained in which the trajectory at the time of moving the figure is expressed as an afterimage.

[0004] An image special effect circuit for realizing a decay effect by using an image from a DVE will be described with reference to FIG. FIG. 2A is a block diagram showing a configuration of a conventional image special effect circuit.

In the figure, the conventional image special effect circuit has
A frame memory 1 for holding a video signal before a frame,
A multiplier 6 that reduces the luminance level of the output from the frame memory 1 by multiplying by a predetermined coefficient, and alternatively outputs the output of the multiplier 6 and the input video signal in response to a key signal. The switching device 5 is included.

Here, it is assumed that the input video signal is composed of frames including a predetermined figure (for example, the above-mentioned "ABC" figure), and the position of the figure in each frame is changing. Then, it is assumed that a key signal is generated as a signal indicating the position of the figure and input to the switch 5. That is, since the position of the figure in each frame is different, the key signal is also different for each frame.

The input video signal is assumed to be stored in a memory (not shown) or the like, and a key signal is generated and input at the time of the input. Then, by synthesizing a plurality of video images of one frame including the graphic, a video signal representing a locus of movement of the graphic is generated.

In such a configuration, the video signal one frame before stored in the frame memory 1 is multiplied by a multiplier 6 by a luminance level and a coefficient for determining the degree of the decay effect, and then one of the switches 5 Applied to input.
The video signal input to the circuit is applied to the other input of the switch 5.

The input to the switch 5 is selected and transmitted by a key signal. That is, when the key signal is “1”, the input video signal is selected, and when the key signal is “0”, the attenuated video signal one frame before from the frame memory 1 is selected and transmitted. The video signal selected by the switch 5 is output from this circuit and is simultaneously written into the frame memory 1.

As described above, since the image of the previous frame is accumulated in the frame memory 1 while being attenuated, it is possible to obtain an effect that when the graphic image moves on the screen, the afterimage of the image trails. You can.

[0011]

Generally, in a three-dimensional image special effect device, various three-dimensional effects having a virtual sense of depth are realized, and depth information for each pixel also exists. However, the circuit for realizing the conventional decay effect described above merely attenuates and accumulates the image one frame before, so that no consideration is given to the depth or the like when moving the image, and the decay effect is not considered. There is a disadvantage that it may become natural.

For example, as shown in FIG. 2B, a case is considered in which a figure is moved as shown by an arrow while moving a figure to the back of the screen. Then, in the conventional circuit, since the image is simply accumulated, the parts that should be hidden overlap and are displayed on the front side of the screen,
There is a disadvantage that the display content becomes unnatural.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to provide an image special effect circuit capable of obtaining a natural decay effect in consideration of the depth of a screen. It is.

[0014]

SUMMARY OF THE INVENTION An image special effect circuit according to the present invention synthesizes a plurality of video images of one frame containing a predetermined graphic to transmit a video signal representing a locus of movement of the graphic. A special effect circuit, a video storage means for holding data of a video signal transmitted immediately before, and a display screen for a pixel portion constituting a figure included in the video signal held in the video storage means. Z value storage means for holding a Z value indicating a virtual depth of
Comparison means for comparing a Z value of a pixel part constituting a figure included in the video signal input to the own circuit with a Z value held in the Z value storage means; Of the data of each pixel constituting the graphic included in the input video signal and the data of each pixel constituting the graphic included in the video signal input to the own circuit, based on the comparison result of the comparing means. Switching transmission means for transmitting the one whose value is indicated to be small.

[0015]

Next, the present invention will be described with reference to the drawings.

FIG. 1A is a block diagram showing the configuration of an embodiment of an image special effect circuit according to the present invention.
Parts equivalent to those in FIG. 3A are indicated by the same reference numerals. In the figure, the point different from the configuration of FIG. 2A is that a Z value indicating a virtual depth from the display screen is input in order to consider the depth of the screen, and the overlapping of figures is improved according to this value. It is a point to do.

In other words, the present embodiment is similar to the conventional circuit in that a plurality of video images of one frame including a predetermined graphic are synthesized to transmit a video signal indicating a locus of the movement of the graphic. In this case, the Z value of a pixel portion forming the figure is also input, and a natural image with a sense of depth is obtained in consideration of the Z value. The Z value is externally input in synchronization with the video signal.

In order to obtain an image in consideration of the Z value, the image special effect circuit according to this embodiment includes a frame memory 1 for storing an input digital image signal for one frame, and a Z value for each pixel of the input image. Z for storing one frame
The buffer 2 is compared with the input Z value and the Z value of the previous frame stored in the Z buffer 2 to determine the size of the latter Z value.
A comparator 3 that outputs a logical value “1” when the value is larger
An AND circuit 4 for outputting the logical product of the output of the comparator 3 and the input key signal; switches 51 and 52 for selecting and outputting one of two inputs according to the output of the AND circuit 4; And a multiplier 6 for attenuating the luminance level of the video signal output from the frame memory 1.
Note that the key signal is a signal indicating the position of the figure as in the conventional case, and is generated based on the video signal.

Next, the operation of the circuit of this embodiment will be described.
The video signal of the previous frame stored in the frame memory 1 is attenuated by multiplying its luminance level by a coefficient that determines the degree of the decay effect by the multiplier 6 and applied to one input of the switch 51. The other input of the switch 51 is applied with the video signal currently input to this circuit. On the other hand, the Z value of the video signal one frame before output from the Z buffer 2 and the Z value of the video signal currently input to this circuit are input to the switch 52, and at the same time, the comparator 3
Are compared. When the Z value from the Z buffer 2 is larger, the logical value “1” is output from the comparator 3.

The output of the comparator 3 is ANDed with the key signal by the AND circuit 4 and becomes the switching control signal of the switch 51. When the output of the AND circuit 4 is the logical product "1", the switch 51 outputs the input video signal, and the switch 52 outputs the input Z value. On the other hand, when the output of the AND circuit 4 is a logical product "0", the switch 51 outputs the video signal from the frame memory 1, and the switch 52 outputs the Z value from the Z buffer.

Here, assuming that the Z value represents a virtual depth from the display screen, if the Z value of the graphic portion of the current input image is smaller than the Z value of the graphic portion one frame before, That is, when the current image is located on the near side of the image one frame before, the switch 51 selects the current image signal. Conversely, when the Z value of the graphic portion of the current input video is larger than the Z value of the graphic portion of one frame before, that is, when the current video is on the back side of the video of one frame before, Output from the frame memory 1,
The video one frame before the luminance of which has been attenuated by the multiplier 6 is selected and output. As a result, when the input image moves three-dimensionally on the display screen, a state in which the input image moves while leaving an afterimage having a sense of depth is displayed.

Therefore, unlike the conventional circuit in which the image one frame before is simply attenuated and accumulated, as a result of considering the depth, an image in which the originally hidden part is correctly hidden as shown in FIG. 1B is obtained. It is.

That is, according to the present invention, the data of the video signal transmitted immediately before is held, and the Z of the pixel portion constituting the graphic included in the held video signal is held.
The stored Z value is compared with the Z value of a pixel portion forming a figure included in the currently input video signal, and the Z value is reduced according to the result of the comparison. Is transmitted, the natural decay effect can be obtained.

It is apparent that an image in consideration of the depth can be obtained without any attenuation.

It is apparent that special effects can be obtained not only for figures but also for various characters and symbols.

[0026]

As described above, the present invention has an effect that a more natural decay effect can be obtained by accumulating and displaying figures in consideration of the virtual depth from the display screen. is there.

[Brief description of the drawings]

FIG. 1 is a diagram showing an image special effect circuit according to an embodiment of the present invention, wherein (a) is a block diagram showing the configuration of the circuit;
(B) is a schematic diagram showing an example of image display by a special effect.

FIG. 2 is a diagram showing a conventional image special effect circuit;
(A) is a block diagram showing a circuit configuration, (b) is a schematic diagram showing an example of moving a figure, and (c) is a schematic diagram showing an image display example by a special effect.

FIG. 3 is a diagram showing a typical display example of a special effect image by DVE.

[Explanation of symbols]

 Reference Signs List 1 frame memory 2 Z buffer 3 comparator 4 AND circuit 6 multiplier 51, 52 switcher

Claims (2)

(57) [Claims] 1. An image special effect circuit for synthesizing a plurality of video images of one frame including a predetermined graphic to transmit a video signal representing a locus of movement of the graphic,
A video storage means for holding data of a video signal transmitted immediately before, and a virtual depth from a display screen of a pixel portion constituting a figure included in the video signal held in the video storage means. Z value storage means for holding the Z value, and a comparison between the Z value of a pixel portion constituting a figure included in the video signal input to the own circuit and the Z value stored in the Z value storage means Comparison means, and data of each pixel constituting a graphic included in the video signal held in the video storage means and data of each pixel constituting a graphic included in the video signal input to the own circuit. And a switching transmission means for transmitting the one whose Z value is indicated to be small by the comparison result of the comparison means. 2. An image special effect circuit according to claim 1, further comprising an attenuating means for attenuating the video signal held in said video storage means and then inputting said video signal to said switching transmission means.