JPH0654255A - Digital video effect device - Google Patents

Abstract

PURPOSE:To freely set the changing pattern of an residual image of a trail effect in a digital video effect device which attains the trail effect, i.e., a special effect that shows the residual image of an image when the image is moved in a screen. CONSTITUTION:A signal switch 3 outputs the input digital video signal to a frame memory 1 at the timing based on a key signal. Meanwhile a frame number memory 5 stores frame numbers outputted from a frame number counter 4 at the timing based on the key signal. A subtractor 6 outputs a signal to show how many number-th video signal is before the video signal that is presently stored in the memory 1. An effect pattern memory 9 outputs the data corresponding to the output of the subtractor 6 from among the data beforehand stored. Then a multiplier 10 multiplies the video signal by the output of the memory 9 and changes the luminance, etc., of the residual image of the video signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image effect device capable of showing an afterimage of an image (hereinafter referred to as trail effect) when the image moves on a screen.

[0002]

2. Description of the Related Art As a conventional digital image effect device, there is a digital image effect device having a circuit for realizing a trail effect as shown in FIG. The digital image effect apparatus shown in FIG. 3 comprises a frame memory 1, a signal switcher 3 and a multiplier 10.

In FIG. 3, the signal switch 3 selects and outputs one of the input digital video signal and the output of the multiplier 10 based on the key signal. This key signal is
This is a signal indicating whether or not the current input digital video signal is valid. The output of the signal switch 3 is output to the outside as an output digital video signal and is also input to and stored in the frame memory 1 for one frame. The output of the frame memory 1 is input to the multiplier 10. The multiplier 10 attenuates the output of the frame memory 1 with an attenuation amount according to an attenuation amount signal input from the outside, and outputs the attenuated signal to the signal switch 3.

As a result, in the above-described conventional digital image effect apparatus, the image signal of the preceding frame is attenuated and accumulated in the frame memory 1. Therefore, when the image moves on the screen, the image becomes an afterimage. It is possible to obtain the trail effect that the image looks like a tail.

[0005]

However, in the above-mentioned conventional digital image effect apparatus, since the image signal of one frame before is uniformly attenuated and stored in the frame memory, it is gradually old at a constant rate. There is a problem that only the simple effect that the afterimage disappears can be realized.

The present invention has been made in view of the above problems, and in a digital image effect apparatus for realizing the trail effect, a digital image effect apparatus capable of freely setting a change pattern of an afterimage due to the trail effect. The purpose is to provide.

[0007]

According to a first aspect of the present invention, there is provided a digital image effect apparatus comprising: a frame memory for storing one frame of a digital image signal; and an output of the frame memory and a digital image signal inputted from the outside. A signal switcher for selectively outputting one of the two based on a control signal, and one of the digital video signals input from the outside.
A frame number counter that outputs a frame number that increases by one for each frame, a write-controllable frame number memory that stores one frame of the frame number based on the control signal, and an output of this frame number memory And a subtracter for calculating the difference between the output of the frame number counter and a predetermined data, and an effect pattern memory for outputting data corresponding to the output of the subtractor from this data, It has a multiplier for calculating the product of the output of the effect pattern memory and the output of the signal switcher.

According to a second aspect of the present invention, there is provided a digital image effect apparatus in which a frame memory for storing one frame of a digital image signal and a signal output from the frame memory or zero are selectively output. A first gate, a signal switcher for selectively outputting one of the output of the first gate and a digital video signal inputted from the outside based on the control signal, and a digital video signal inputted from the outside. A frame number counter that outputs a frame number that increases by one for each frame;
A write controllable frame number memory that stores one frame of the frame number based on the control signal; a subtractor that calculates a difference between the output of the frame number memory and the output of the frame number counter; A zero comparator that determines whether the output of the subtractor is zero and controls the first gate based on the determination result, and a signal that is controlled by the control signal and that is supplied from the subtractor and zero. A second gate that selectively outputs one of them, an effect pattern memory that stores predetermined data in advance, and outputs data corresponding to the output of the second gate from this data, and this effect It has a multiplier for calculating the product of the output of the pattern memory and the output of the signal switch.

[0009]

In the digital video effect apparatus according to the present invention, the signal switcher outputs the digital video signal input from the outside to the frame memory at the timing based on the control signal which is a key signal and stores it. Further, the frame number memory inputs and stores the frame number output by the frame number counter at a timing based on the control signal. The subtractor outputs a signal indicating how many frames before the video signal stored in the current frame memory is a video signal externally applied to the digital video effect apparatus. The effect pattern memory outputs the data corresponding to the output of the subtracter among the data such as the brightness control signal stored in advance. The multiplier multiplies the video signal by the output of the effect pattern memory to change the brightness of the afterimage of the video signal and the like.

As a result, the digital video effect apparatus according to the present invention inputs a digital video signal and adds a trail effect which causes an afterimage of the image when the image moves on the screen to the digital video signal. Further, by changing the data stored in advance in the effect pattern memory, the change pattern of the afterimage brightness or the like in the trail effect can be freely set.

Since the frame number output from the frame number counter is finite, in order to prevent duplication of the frame number, a zero comparison is performed to determine whether the output of the subtractor is zero. It is preferable to provide a first gate and the like, which is interposed between the output end of the frame and the frame memory and the input end of the signal switch, and which is controlled by the zero comparator.

[0012]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a digital image effect apparatus according to an embodiment of the present invention. In FIG. 1, the same components as those of the conventional digital image effect apparatus shown in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the digital video effect apparatus according to this embodiment receives a frame memory 1 for storing one frame of an input digital video signal and an output of the frame memory 1, and outputs the same as it is. Or a gate 2 for outputting zero, and a first input digital video signal
Of the input signal and the output of the gate 2 as the second input signal, selecting one of these input signals on the basis of the key signal and outputting the selected signal, one for each frame of the video signal. The frame number counter 4 which outputs an increasing frame number, the frame number memory 5 which can store the frame number for one frame and which can be written and controlled, the output of the frame number memory 5 and the frame number counter 4 A subtracter 6 for calculating the difference between the output and the subtractor 6
A zero comparator 7 for determining whether or not the output of
A gate 8 that inputs the output of the subtractor 6 and outputs it as it is or outputs zero, an effect pattern memory 9 that selectively outputs data stored in advance in accordance with the output of this gate 8, and a signal switch A multiplier 10 for calculating the product of the output of the device 3 and the output of the effect pattern memory 9.

Next, the operation of the digital image effect apparatus according to this embodiment, which is constructed as described above, will be described. First, the signal switch 3 selects and outputs one of the input digital video signal and the output of the gate 2 based on the key signal. Further, the output of the signal switch 3 is the multiplier 10
Is input to the frame memory 1 and stored therein.

On the other hand, the frame number counter 4 outputs a frame number for each frame of the input digital video signal, and the frame number memory 5 if the key signal is valid.
The frame number is written in. Further, the frame number memory 5 outputs the latest written frame number in the written frame numbers. Subtractor 6
Is a difference between the output of the frame number counter 4 and the output of the frame number memory 5, and outputs a signal indicating how many frames before the video signal currently stored in the frame memory 1 is the input digital video signal. To do. The output of the subtractor 6 is input to the effect pattern memory 9 via the gate 8 controlled by the key signal. Effect pattern memory 9
Outputs, as the attenuation amount signal, data corresponding to the input signal from the data stored in advance.

The video signal output from the signal switch 3 is multiplied by the attenuation amount signal output from the effect pattern memory 9 in the multiplier 10 to control the brightness and the like,
It is output to the outside as a digital video signal. Since the frame number output from the frame number counter 4 is finite, the output of the subtractor 6 is not limited to the gate 8 and the zero comparator 7 in order to prevent the frame numbers from overlapping.
Is also input to the zero comparator 7 to determine whether the output of the subtractor 6 is zero, and the result of the determination is used as a control signal for the gate 2.

FIG. 2 shows the effect of the digital image effect apparatus according to the present embodiment shown in FIG. 1, (a) shows an example of the input / output characteristics of the effect pattern memory 9, and (b).
Shows the image represented by the input digital video signal, and (C) shows the image represented by the output digital video signal.

In the digital video effect apparatus according to the present embodiment, the input / output characteristics of the effect pattern memory 9 are set as shown in the graph of FIG. 2 (a), and the input digital image having the motion shown in FIG. 2 (b) is set. When the video signal is input, the multiplier 10
2C shows the output digital video signal which is the output of the image A. The effect that the image A moves while gradually becoming brighter, and then the image A moves while gradually becoming darker is obtained. .

[0020]

As described above, according to the digital image effect apparatus of the present invention, in the digital image effect apparatus for realizing the trail effect, the change pattern of the afterimage brightness or the like in the trail effect can be freely set. Therefore, it is possible to realize a special trail effect which is impossible with the conventional digital image effect device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a digital image effect device according to an embodiment of the present invention.

2A and 2B show effects of the digital video effect apparatus shown in FIG. 1, FIG. 2A is a graph showing an example of input / output characteristics of an effect pattern memory, and FIG. 2B is an image represented by an input digital video signal. (C) shows an image represented by an output digital video signal.

FIG. 3 is a block diagram showing an example of a conventional digital image effect device.

[Explanation of symbols]

 1; Frame memory 2, 8; Gate 3; Signal switcher 4; Frame number counter 5; Frame number memory 6; Subtractor 7; Zero comparator 9; Effect pattern memory 10; Multiplier

Claims (2)

[Claims] 1. A frame memory for storing one frame of a digital video signal, and a signal switcher for selectively outputting one of an output of the frame memory and a digital video signal input from the outside based on a control signal. A frame number counter that outputs a frame number that is incremented by one for each frame of the digital video signal input from the outside, and write control that stores one frame of the frame number based on the control signal A frame number memory, a subtracter for calculating the difference between the output of the frame number memory and the output of the frame number counter, and predetermined data stored in advance, which corresponds to the output of the subtractor Of the effect pattern memory for outputting the data to be output, and the output of the effect pattern memory and the output of the signal switcher. And a multiplier that calculates a product. 2. A frame memory for storing one frame of a digital video signal, a first gate for selectively outputting one of a signal given from the frame memory and zero, and a first gate of the first gate. A signal switcher that selectively outputs one of an output and an externally input digital video signal based on the control signal, and a frame number that is incremented by one for each frame of the externally input digital video signal. A frame number counter for outputting the frame number, a write controllable frame number memory for storing one frame of the frame number based on the control signal, and an output of the frame number memory and an output of the frame number counter. A subtractor for calculating the difference and whether or not the output of the subtractor is zero are determined, and the first gate is determined based on the determination result. A zero comparator that controls the gate, a second gate that is controlled by the control signal and selectively outputs one of the signal given by the subtractor and zero, and predetermined data is stored in advance. Yes An effect pattern memory for outputting data corresponding to the output of the second gate from the data, and a multiplier for calculating the product of the output of the effect pattern memory and the output of the signal switcher are provided. A digital image effect device characterized by.