JPH0517752B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a special effect waveform generator used in image devices and the like.

[Prior Art] Conventionally, this type of special effect waveform generator adds and subtracts fader control data to a waveform that is a combination of horizontal and vertical periodic fundamental waves, and when clipping the waveform that has been gain controlled using soft width control data. Since clipping was performed at equally spaced points above and below the zero point of the gain control, a soft edge effect was produced on both sides of the waveform, as shown in FIG. Note that P shown in the figure is the waveform size.

[Problems to be Solved by the Invention] However, in the conventional special effect waveform generator described above, as shown in FIG. will also change, so
When linking data with digital special effects equipment, even if the waveform size is constant and only the soft width data is changed, with digital special effects equipment, the size of the video signal must also be changed, and the soft width control data and soft width Since the relationship is not linear, it is not easy to calculate the size of a video signal for a digital special effects device.

[Means for Solving the Problems] An object of the present invention is to solve the above problems and provide a special effect waveform generator that can keep the waveform size constant even when the soft width is changed.

In order to achieve the above object, a special effect waveform generator according to the present invention includes an effect fundamental wave generation circuit that generates effect fundamental waves of horizontal and vertical scanning periods, and effects of horizontal and vertical periods from the effect fundamental wave generation circuit. A synthesis circuit that synthesizes fundamental waves; an addition/subtraction circuit that inputs the output waveform of the synthesis circuit and adds/subtracts fader control data; and a multiplication circuit that inputs the output waveform of the addition/subtraction circuit and performs gain control using soft width control data. and a clip circuit that receives the output waveform of the multiplier circuit and clips the waveform using the zero point of the gain control as a reference clip level.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a special effect waveform generator according to an embodiment of the present invention.

In the figure, the special effect waveform generator according to this embodiment includes a fundamental wave generation circuit 1 and a waveform synthesis circuit 2.
, an addition/subtraction circuit 3 , a multiplication circuit 4 , and a clip circuit 5 .

A fundamental wave generation circuit 1 generates fundamental sawtooth waves with horizontal and vertical scanning periods, and a waveform synthesis circuit 2
supply to The waveform synthesis circuit 2 synthesizes basic sawtooth waves in the horizontal and vertical directions. Here, Fig. 2 a
Taking the waveform shown in as an example, the synthesized waveform is the second waveform.
This results in a three-dimensional waveform as shown in Figure b.

The addition/subtraction circuit 3 adds or subtracts the fader control data 10 to the three-dimensional waveform from the waveform synthesis circuit 2 to determine the waveform size. The multiplication circuit 4 performs gain control using soft width control data 11. The clip circuit 5 receives the output waveform of the multiplier circuit 4,
The waveform is clipped using the zero point of the gain control as the reference clip level.

Next, the operation of this embodiment will be explained.

The fundamental sawtooth waves in the horizontal and vertical directions generated by the fundamental wave generating circuit 1 are synthesized into a three-dimensional waveform by the waveform synthesizing circuit 2 as shown in FIGS. 2a and 2b described above. This stereoscopic waveform is subjected to addition/subtraction of fader control data 10 by an addition/subtraction circuit 3, and the waveform size is determined by changing the level offset value of the stereoscopic waveform with respect to a fixed slice plane.

In order to easily explain this operation, let us take as an example a waveform consisting of only the horizontal component of a three-dimensional waveform, as shown in FIG. 3a. In the figure, the vertical direction V is the waveform level, the horizontal direction H is the horizontal component, and A1 is the fixed slice plane.
H1 is the waveform size when fader control data 10 is '0', H2 is fader control data 10
is 'α(>0)', V1 is the center level of the waveform when fader control data 10 is '0', V2 is fader control data 10
shows the center level of the waveform when is 'α'.

After the waveform size is determined in this way, the multiplication circuit 1 uses the soft width control data 11 to change the slope of the waveform as shown in FIG. 3b, thereby changing the softness of the edges of the waveform. Incidentally, in the figure, G is the zero point of the gain control.
Then, the clip circuit 5 clips the waveform whose slope has been changed by the multiplier circuit 4, using the zero point G of the gain control as a reference clip level, as shown in FIG. 4, to form the final output waveform Q. . In the figure, C1 indicates the upper clip point, and C2 indicates the lower clip point passing through the zero point G of the gain control.

As described above, in this embodiment, the zero point G of the gain control is used as the reference clip level, so the soft edge effect, which conventionally was applied to both sides of the waveform, is applied only to the inside of the waveform, and therefore even when the soft width is changed. This allows the size of the waveform to remain constant.

FIG. 5 is a block diagram showing the configuration when data is linked with a digital special effects device. In the figure, a CPU 6 which receives a fader control input F and outputs size control data S, and the size control data S
a special effect waveform generator 7 that outputs a key signal K in response to the input video signal A; a digital special effect device 8 that calculates the size of the input video signal A according to the size control, reduces the image, and outputs the video signal A'; It consists of a video mixing amplifier 9 that receives input video signal B, video signal A', and key signal K, synthesizes video, and outputs the result.
When the output waveform of key signal K is made into a soft waveform,
Even if the soft width is changed, the waveform size can be kept constant as described above, so there is no need to change the size control on the digital special effects device 8 side as the soft width changes.

[Effects of the Invention] As explained above, the present invention provides an effect fundamental wave generation circuit that generates an effect fundamental wave in each horizontal and vertical (television) scanning period, and a horizontal and vertical cycle from the effect fundamental wave generation circuit. A synthesis circuit that synthesizes the fundamental wave; an addition/subtraction circuit that receives the output waveform of the synthesis circuit and adds/subtracts fader control data; and a multiplication circuit that receives the output waveform of the addition/subtraction circuit and performs gain control using soft width control data. a clip circuit that receives the output waveform of the multiplier circuit and performs clipping using the zero point of the gain control as a reference clip level;
By clipping the zero point of the gain control as the reference clip level, the soft edge effect is applied only to the inside of the waveform, which has the effect of keeping the waveform size constant even if the soft width is changed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a special effect waveform generator according to an embodiment of the present invention, FIGS. 2a and 2b are diagrams illustrating the operation of a waveform synthesis circuit, and FIGS. 3a and 3b are an addition/subtraction circuit and a multiplication circuit. Fig. 4 is an explanatory diagram of the operation of the clip circuit, Fig. 5 is a block diagram showing the configuration when data is linked with a digital special effects device, and Fig. 6 is a soft edge effect using a conventional special effects waveform generator. FIG. 1: Fundamental wave generation circuit, 2: Waveform synthesis circuit, 3:
Addition/subtraction circuit, 4: Multiplication circuit, 5: Clip circuit,
10: Fader control data, 11: Soft width control data.

Claims (1)

[Claims] 1. An effect fundamental wave generation circuit that generates effect fundamental waves of horizontal and vertical scanning periods, a synthesis circuit that synthesizes effect fundamental waves of horizontal and vertical periods from the effect fundamental wave generation circuit, and an output waveform of the synthesis circuit. an addition/subtraction circuit that inputs and adds/subtracts fader control data; a multiplication circuit that receives the output waveform of the addition/subtraction circuit and performs gain control using soft width control data; and a multiplication circuit that receives the output waveform of the multiplication circuit and determines the zero point of gain control. A special effects waveform generator comprising a clipping circuit that clips a waveform as a reference clip level.