JP2502957B2 - Image converter - Google Patents

Description

The present invention relates to an image conversion device that performs geometric conversion by digitally processing image data. The present invention is used as a special effect device for broadcasting and an animation creating device.

“Background Technology and Problems Thereof” The applicant of the present application has already proposed an image conversion device as described below (see, for example, Japanese Patent Laid-Open No. 58-219664). This image conversion device divides the input image into blocks, calculates the area on the image surface converted into a predetermined pattern of the divided blocks, reads the pixels in this block from the input image memory, and outputs the pixels. It is written in the image memory.

The algorithm of the above image conversion apparatus will be further described below.

The entire original image is divided into (several pixels x several pixels) blocks, the representative points of each block are subjected to predetermined conversion, and the position after conversion is obtained.

Linearly approximate the transformation (including non-linear one) near the representative point.

Find the inverse of the approximated linear transformation (also linear transformation). (The inverse transformation function is obtained.) This approximated inverse transformation is applied to all the pixels near the transformed representative point. Find the address of the original image corresponding to the linear approximation.

The above-mentioned image conversion device converts the entire input image. However, if it is possible to perform the geometric conversion only on a part of an arbitrary pattern area of the input image, the variety of the geometric conversion can be increased.

"Object of the Invention" The present invention is intended to realize an image conversion apparatus capable of performing geometric conversion of only a part of an input image. According to the present invention, for example, it is possible to previously write image data as a background in the output image memory and superimpose the background and the converted image, and it is possible to increase the types of image conversion.

[Summary of the Invention] The present invention relates to an improvement of the above-mentioned image conversion device proposed above. A write pulse generating circuit for controlling writing of an image signal to an output image memory is provided, and the write pulse generating circuit is provided. The generation of the writing pulse is controlled by discriminating the level of the image signal or the like or by a key signal from the outside so that only a part of the input image is converted.

"Embodiment" FIG. 1 shows the overall construction of an embodiment of the present invention.
In the figure, 1 indicates a first processor. An input / output device 2 and a large capacity memory 3 are provided in association with the processor 1. A program corresponding to the type of image conversion is transferred from the large-capacity memory 3 to the high-speed memory of the processor 1 by a command specifying the image conversion from the input / output device 2, and the parameter of the program is changed using the input / output device 2. Is done. Then, this program is transferred to the second processor 4.

In this case, it is possible that the second processor 4 reads the large capacity memory 3 and changes the program, and the first processor 1 only transfers the parameters.

The second processor 4 executes the given program. That is, the representative point of each block of the original image is converted, the calculation for obtaining the position after conversion and other necessary information are created and stored in the buffer memory 5. This is a process corresponding to the step, the step, and the step.

Reference numeral 6 denotes the first dedicated hardware, which reads information about the conversion for each representative point performed by the processor 4 from the buffer memory 5 and uses this information to read the second dedicated hardware. The area of the wear 7 to be processed is designated. That is, as shown in FIG.
The dedicated hardware 7 is instructed what kind of area B on the converted image IM ₂ a certain area A on the original image IM ₁ changes.

The data of the original image read from the image memory 8 is supplied to the second dedicated hardware 7, and the output data of the dedicated hardware 7 is written in the image memory 9. The dedicated hardware 7 obtains read addresses for all pixels within the processing range. That is, the step processing in the processing algorithm described above is performed. Then, the image data is read from the image memory 8 based on the obtained read address, and written in the image memory 9 after processing such as interpolation. When processing color video data, component-encoded color video data composed of a luminance signal and two types of color difference signals is used. Dedicated hardware 7, image memory 8, 9
Is provided for each component.

FIG. 3 and FIG. 4 show an example and another example of image conversion to which the present invention is applied. Figure 3 shows the original image
The case where IM ₁ includes the doll 10 in the center and a converted image IM ₂ is formed such that only the circular portion 11 (shown by the broken line) around the doll 10 is wrapped around the cylindrical surface. Converted image IM ₂
The background portion 12 of is a predetermined color or image written in the image memory 9 in advance. In addition, FIG. 4 shows the original image IM ₁ obtained by photographing an alphabet written on the transparent film 13, and the transparent film 13 forms a transformed image IM ₂ which is rounded. This is the case. In FIG. 4, the outline of the transparent film 13 is shown by a broken line,
Of course, this cannot be seen, and the converted image IM ₂ feels as if the alphabet changed independently.

An embodiment of the present invention will be further described with reference to FIG. An image data correction circuit 14 is provided in the preceding stage of the image memory 8 in the image conversion apparatus having the same configuration as that of FIG. An external key signal is supplied to the image data correction circuit 14 from a terminal 15. This external key signal is a digital signal that changes corresponding to the portion (the circular portion 11 in FIG. 3 or the transparent film 13 in FIG. 4) of the input image to be geometrically transformed. The image data other than the portion to be converted is corrected by the external key signal to be different from the original image data, and is output from the image data correction circuit 14.

Assuming that the doll 10 having a certain brightness is located in front of the white background of the original image IM ₁ shown in FIG. 3, the correction to make the area other than the circular portion 11 the black level is the image data correction circuit. At 14. As shown in FIG. 4, when substantially only the alphanumeric film is the object of image conversion, it is not necessary to make a correction so that the transparent film 13 and the other parts have different levels. That is, of the processed image data, only the image data of a level close to the black level may be written in the image memory 9.

Further, the output of the image memory 8 is supplied to the write data generating circuit 16 of the dedicated hardware 7. The write data generation circuit 16 is controlled by the dedicated hardware 6, reads image data from the image memory 8 and performs interpolation processing to generate write data. This write data is supplied to the image memory 9 and the comparator 17. This comparator 17 generates a write pulse generation prohibition signal for write pulse generation circuit 18.

The write pulse is for writing write data to the image memory 9, and is generated for each pixel.
The comparator 17 determines from the write data itself whether this write data is included in the portion to be converted. As mentioned above, in the conversion shown in FIG.
When the correction is performed with the black level other than the circular portion 11, the write data close to the black level is detected by the comparator 17, and the comparator 17 outputs the write pulse generation prohibition signal. As a result, write data close to the black level is not written in the image memory 9. In addition, the fourth
In the case of the conversion shown in the figure, without modifying the image data, the write data other than those of approximately black level is detected by the comparator 17, and the image data of this approximately black level, that is, the image data of alphabet Only is written into the image memory 9.

In addition, as described above, the difference between the hue and the difference may be used to distinguish between the part to be converted and the part that is not to be converted. For example, the input image data of the portion which is not converted is corrected to blue color data, and the comparator 17 forms a write pulse generation prohibition signal by comparing this blue hue and the hue of the write data.
This difference in hue can be detected from the color difference signal.

"Application Example" In addition to correcting the input image data written in the image memory 8, a predetermined external key signal may be supplied to the write pulse generating circuit 18. For this purpose, a pattern generating circuit for generating a pattern of a portion of the input image to be converted is provided, and the output is converted into a digital signal. In this case, one pixel corresponds to one bit. And
The same processing as the generation of the write data is performed on this pattern data, the pattern data and the write data are output in synchronization, and the write data is written to the image memory 9 by the processed pattern data. Controlled.

"Effect of the Invention" According to the present invention, it is possible to geometrically transform only a portion of an arbitrary pattern in an input image. Therefore, the types of image conversion can be increased. Further, if the write data itself is compared with a predetermined lightness or a predetermined hue so as to distinguish between a portion to be converted and a portion not to be converted, it is possible to partially use the simple hardware. The conversion can be done.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall construction of an embodiment of the present invention, FIGS. 2, 3, and 4 are schematic diagrams used for explaining image conversion, and FIG. 5 is an embodiment of the present invention. It is a block diagram which shows the structure of the principal part of an example. 1,4 …… Processor, 6,7 …… Dedicated hardware, 8,9 ……
Image memory, 14 ... Image data correction circuit, 17 ... Comparator, 18 ... Write pulse generation circuit.

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-57-57364 (JP, A) JP-A-57-150063 (JP, A) JP-A-54-161229 (JP, A) JP-A-56- 131176 (JP, A) JP-A-54-142943 (JP, A) JP-A-55-129387 (JP, A)

Claims (1)

(57) [Claims] 1. An image conversion device for converting an input image signal stored in an input image memory into a predetermined geometric pattern and writing the same in an output image memory to obtain an output image signal. A first means for obtaining information about conversion when a representative point of each divided block is converted according to the predetermined conversion pattern, and the information about the conversion is stored. Corresponding buffer memory, second information for reading the information about the conversion from the buffer memory, and calculating a corresponding block area on the converted output image of each block, and pixels corresponding to the pixels in the block area. A third procedure in which the pixels in the block are obtained by inverse calculation, read from the input image memory, and written in the output image memory. And in the third means, by comparing the lightness or hue of each pixel read from the input image memory with a predetermined value, only the pixels of the image of the portion to be converted are described above. An image conversion device comprising: an output image memory;