JPH04138782A - Special effect device for television - Google Patents

Abstract

PURPOSE:To set the effective range of a picture in an area other than the one before the form conversion of a video signal by generating a key signal while utilizing the only reading address of a memory where a reading address generator is generated in a key signal generator. CONSTITUTION:A reading address generator 7 generates the reading address while inputting a writing address front a writing address generator 6 and performing the matrix conversion indicated by a three-dimensional matrix in the case of performing affine conversion. This reading address is inputted to a memory 5, and a prescribed signal composed of the sample point is read out from the memory 5, and this signal is inputted to an interpolation device 8. A key signal generator 10 generates the key signal based on the above- mentioned reading address, and an adder 9 with background adds the background based on this key signal. Therefore, since the effective range of the picture is not influenced by the writing address, the effective range of the picture can be set outside the area before the form conversion of the video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a special effects device for television programs that is used in a studio device for television signals and adds special effects to television video signals.

[Prior Art] Conventionally, this type of special effects device for television series uses a comparator to compare a write address and a fixed value indicating an effective range within a two-dimensional plane before performing three-dimensional shape conversion. Find the 1-bit signal indicating the magnitude relationship obtained by
This is written into memory in the same way as a video signal, and read out at a read address that yields a predetermined shape transformation.
Interpolation of sampling points is performed by an interpolator.

FIG. 3 is a block diagram showing a conventional television special effects device.

A television video signal input to the video signal input terminal 31 is input to the A/D converter 33.

This A/D converter 33 samples and quantizes the video signal and converts it into a digital signal. Further, a reference synchronization signal is input to the reference synchronization signal input terminal 32 . The timing pulse generator 35 receives this reference synchronization signal and outputs a timing pulse.

This timing pulse is input to a key signal generator 34 and a write address generator 38. The write address generator 38 generates a write address based on this timing pulse, and outputs this write address to the key signal generator 34, the memories 36 and 37, and the read address generator 39. The memory 36 receives this write address and stores the output of the A/D converter 33. The read address generator 39 performs a predetermined operation using the write address to obtain a read address and outputs it to the memories 36 and 37.

The key signal generator 34 is provided with a comparator, which compares the write address and a fixed value indicating the effective range of the image in a two-dimensional plane, and indicates the magnitude relationship between the write address and the fixed value. Generates a bit signal. memory 3
7 stores this 1-bit key signal.

Interpolators 40 and 41 read sampled video signal values from the memories 36 and 37 at read addresses from which a predetermined shape transformation can be obtained, perform interpolation between sampling points, and use the results as a background signal. Output to adder 42. A background adder 42 adds a background to the video signal based on the outputs of the two interpolators 40 and 41. The D/A converter 43 performs D/A conversion on the output of the background adder 42 and outputs it to the output terminal 44.

In this way, it is possible to obtain an image with special effects such as rotation, positional movement, enlargement and reduction.

[Problems to be Solved by the Invention] However, the conventional television special effects apparatus has the following problems. That is, the key signal generator 34 receives a write address and generates a 1-bit key signal based on this write address. and,
This 1-bit signal is written into the memory 37, read out in the same way as the video signal, and interpolated in the same way as the video signal. Therefore, it is not possible to set the effective range of the image outside the area before the shape conversion of the video signal.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide a special effects device for television, which can set the effective range of an image to an area other than the area before shape conversion of a video signal.

[Means to solve the problem]

The special effects device for television series according to the present invention is an A/
a D converter, a timing pulse generator that inputs a reference synchronization signal and generates a timing pulse, a write address generator that generates a write address based on the timing pulse, and an A/D converter that inputs the write address and generates a timing pulse. A memory that stores the output of the converter, a read address generator that inputs the write address and performs affine transformation to generate a read address, and a signal that is read from the memory between sampling points. an interpolator that performs interpolation, and a key signal generator that generates a key signal indicating a valid range of an image based on the read address;
The present invention is characterized by comprising a background adder that adds a background to the output of the interpolator based on this key signal, and a D/A converter that converts the output of the background adder from D/A.

[Operation] In the present invention, the read address generator receives a write address and performs affine transformation to generate a read address. Then, the key signal generator generates a key signal based on the output of the read address generator. Therefore, the effective range of this key signal can be set without being restricted by the write address. This results in
The effective range of the image can also be set to an area other than the area before the shape conversion of the video signal.

In this case, the key signal generator includes, for example, a comparator that compares the output of the read address generator with a fixed value indicating the effective range, and a comparator that compares the output of the read address generator with a fixed value indicating the effective range, and When the output of the read address is smaller than the fixed value, it outputs a predetermined maximum value as being within the valid range, and when the output of the read address is smaller than the fixed value, it outputs the predetermined minimum value as being outside the valid range. It is only necessary to provide a switching means for outputting the decimal part of the read address as an intermediate point between within the valid range and outside the valid range when they match.

[Embodiments] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a television special effects device according to an embodiment of the present invention.

The video signal input to the video signal input terminal 1 is input to the A/D converter 3, and is converted into a digital signal by being sampled and quantized by the A/D converter 3.

On the other hand, the reference synchronization signal input from the reference synchronization signal input terminal 2 is input to the timing pulse generator 4. The timing pulse generator 4 generates a clock signal, a horizontal synchronization signal, and a vertical synchronization signal based on the reference period signal, and sends these signals to each block. A write address generator 6 generates a write address based on the output of the timing pulse generator 4. A/D converter 3
The digitized signal is written into the memory 5 for one frame by the write address sent from the write address generator 6.

The read address generator 7 inputs the write address from the write address generator 6, rotates, moves, enlarges or reduces the two-dimensional television signal in three dimensions, and further projects it onto a two-dimensional plane. A read address is generated by performing matrix transformation indicated by a three-dimensional matrix when the transformation is performed.

In other words, the horizontal direction of the write address is X1, and the vertical direction is Y
Then, the read address generator 7 calculates the read address XI by performing the calculations shown in the first equation and the second equation below.
Calculate y.

x= (Ax+By+C)/(px+QY+r)...
-(1) y= (Dx+Ey×F)/(px×qy×r) However, A to F and p to r are variables of affine transformation.

This read address is input to the memory 5, and the memory 5
A predetermined signal consisting of sample points is read out from , and this signal is input to the interpolator 8 . This read address is also input to the key signal generator 10. As will be described later, this key signal generator 10 includes a comparison circuit that compares an input signal with a fixed value indicating an effective range, and a changeover switch that generates a key signal based on the output of this comparison circuit. This key signal is sent to the background adder 9.

The interpolator 8 interpolates the signal input from the memory 5 at a position within the sampling point. A background adder 9 adds a background to the output of the interpolator 8 based on the output of the key signal generator 10. The output of the background adder 9 is input to a D/A converter 11, where it is D/A converted and output to an output terminal 12.

FIG. 2 is a circuit diagram showing the configuration of the key signal generator 10 in this embodiment.

This key signal generator 10 includes four comparison switching circuits 22,
23, 24, 25 and three NAM (non-adding) circuits 2
B, equipped with 27.28. The comparison switching circuit 22 detects the left end of the effective range of the image, the comparison switching circuit 23 detects the right end of the effective range of the image, the comparison switching circuit 23 detects the upper end of the effective range of the image, and the comparison switching circuit 25 detects the right end of the effective range of the image. Detects the bottom edge of the image's effective range. Each comparison switching circuit 22, 23, 2
4゜25 has the same configuration, so the comparison switching circuit 2
The configuration of only 2 will be explained.

The comparison switching circuit 22 includes a comparator 30 and a changeover switch 20a.
, 20b, etc. The read address output from the read address generator 7 is input to the read address input terminal 21 of the comparison switching circuit 22. Note that this read address consists of an integer part and a decimal part.

The integer part of the read address corresponds to the address at the time of writing into the memory, and therefore corresponds to the pixel of the input signal. On the other hand, the decimal part is generated by performing affine transformation on the value of the write address, and indicates the area between pixels of the input signal.

The comparator 30 has two input terminals, one input terminal receives the horizontal integer part (A) of the read address, and the other input terminal receives a fixed value indicating information on the left edge of the screen. M
IN(B) is input.

Then, the comparator 30 compares these two values, and when the read address (A) is smaller than or equal to MIN (B), it is L level, and when it is larger, it is H level, which is the A>B signal. , outputs an A=B signal which is at H level when the read address is equal to MIN, and is at L level when the two are not equal.

The switch 20a is driven by the A=B signal and outputs either the decimal part of the read address or the minimum value MIN. Further, the switch 20b is driven by the A>B signal, and the output of the switch 20a or the maximum value MAX
It is designed to output one of the two. Therefore,
The comparison switching circuit 22 outputs the values shown in Table 1 below, depending on the magnitude relationship between the horizontal integer part A of the read address and the fixed value B indicating the left edge information of the screen.

Table 1 In this way, the effective range of the left end of the image after shape conversion is
Interpolation is performed with a precision obtained by dividing the distance between input pixels and pixels by the number indicated by the number of bits in the decimal part. The right edge, top edge, and bottom edge of the image are also determined in the same manner.

The outputs of the comparison switching circuits 22.23 and 24.25 are non-additively combined (NAM) by NAM circuits 2B and 27.28, and outputted to the key signal output terminal 29 as a key signal.

In this embodiment, as described above, the read address generator 7 receives the write address from the write address generator 6, performs affine transformation on this write address, and generates a read address. Then, the key signal generator 10 generates a key signal based on this read address, and the background adder 9 adds a background based on this key signal.

Therefore, since the effective range of the image is not affected by the write address, it is possible to set the effective range of the image outside the area before the shape conversion of the video signal.

[Effects of the Invention] As explained above, according to the present invention, the key signal generator generates a key signal including interpolation after shape conversion using only the memory read address generated by the read address generator. Therefore, the effective range of the image can be set to a region other than the region before shape conversion of the video signal without being limited to the region of the two-dimensional plane of the input signal.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a special effects device for television according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing the configuration of a key signal generator thereof, and FIG. FIG. 2 is a block diagram showing an effect device. 1.31; Video signal input terminal, 2.32; Reference synchronization signal input terminal, 3, 33; A/D converter, 4°35; Timing pulse generator, 5.36.37; Memory, 8.38
; Write address generator, 7.39; Read address generator, 8.40° 41; Interpolator, 9, 42; Background adder, 10, 34; Key signal generator, 11, 43; D/
A converter, 12.44; Output terminal, 21; Read address input terminal, 22, 23, 24, 25; Comparison switching circuit, 26° 27° 28; NAM circuit, 29; Key signal output terminal

Claims (2)

[Claims] (1) An A/D converter that inputs a television video signal and performs sampling and quantization; a timing pulse generator that inputs a reference synchronization signal and generates a timing pulse;
a write address generator that generates a write address based on the timing pulse; a memory that inputs the write address and stores the output of the A/D converter; and a memory that inputs the write address and performs affine transformation to generate a read address. an interpolator that interpolates between sampling points of the signal read from the memory, and a key signal that indicates the effective range of the image based on the read address. It has a key signal generator that generates a key signal, a background adder that adds a background to the output of the interpolator based on the key signal, and a D/A converter that converts the output of the background adder from D/A. A special effects device for television, which is characterized by: (2) The key signal generator includes a comparator that compares the output of the read address generator with a fixed value indicating the effective range of the image, and a specific minimum value based on the output of the comparator.
2. The special effects apparatus for television according to claim 1, further comprising a switching means for outputting either one of a specific maximum value and a decimal part of the read address.