JPH0712208B2 - Image converter - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image conversion device that can be used for image shape conversion such as an image special effect device.

2. Description of the Related Art In recent years, various special effects have become possible due to advances in image processing technology, and many special effect devices have been announced. In these special effect devices, conversion operations are performed not only on image data but also on addresses.

A conventional image conversion apparatus will be described below with reference to the drawings.

FIG. 3 shows a conventional image conversion device, 31 is a conversion address generation device, 32 is a pixel coordinate value on a new image plane, and 33 is
Is a point coordinate value on the original image plane, 34 is a coordinate correspondence memory, 35 is a read address control device, 36 is a write address control device,
37 is an image memory, 38 is a local reduction ratio of the original image, 39 is a reduction ratio memory, and 3a is a two-dimensional adaptive filter.

The operation of the image conversion apparatus configured as described above will be described below with reference to FIG.

First, the conversion address generation device 31 determines a pixel coordinate value 32 on the new image plane according to the given three-dimensional geometric structure expression, coefficient, position, direction and viewpoint position, and screen position,
The point coordinate value 33 on the original image plane corresponding to the pixel coordinate value 32 on the new image plane and the local reduction rate 38 of the original image are output.
The coordinate correspondence memory 34 stores the point coordinate value 33 on the original image plane by using the pixel coordinate value 32 on the new image plane for address designation. The reduction ratio memory 39 stores the local reduction ratio 38 of the original image. The two-dimensional adaptive filter 3a has the above reduction rate memory.
High frequency components are removed while changing the characteristics of the local filter according to the contents of 39. The image memory 37 sequentially stores the original image from which the high-frequency component is removed by the two-dimensional adaptive filter under the control of the write address controller 36. The read address control device 35 generates the new image by reading the image data of the original image from the image memory 37 in accordance with the point coordinate values on the original image plane extracted from the coordinate correspondence memory 34 at the timing of the new image. For example, it is as described in Technical Report Vol.9, No.20, PPOE62-9 of the Television Society.

Problems to be Solved by the Invention However, there is a problem that the mapping shape generated by the above configuration cannot be recognized on a new image as a three-dimensional geometric shape unless it is rotated / moved. Was.

In view of the above problems, it is an object of the present invention to provide an image conversion device capable of creating a high-impact effect image by adding a shadow to a mapping shape.

Means for Solving the Problems In order to solve the above problems, the image conversion device of the present invention is
It is configured by adding a brightness conversion unit capable of changing the brightness according to the local reduction ratio of the shape and a brightness conversion unit capable of changing the brightness information of the pixel corresponding to the pixel position coordinate value on the new image.

Effect The present invention changes the brightness of the original image according to the local reduction ratio of the shape by the above-described configuration, and further changes the brightness of the corresponding pixel according to the pixel position coordinate value on the new image, thereby making it possible to emit light from an oblique direction. It is possible to add a pseudo shadow when applied, and to create a high-impact effect video.

Example Normally, in order to add a shadow when the original image is mapped to a three-dimensional shape, the brightness information in the pixel information of the original image may be increased or decreased according to the orientation of the shape surface. In the present invention, the increase of the calculation load is suppressed to the necessary minimum by using the local reduction rate of the shape and the pixel position coordinate value on the new image as the increase / decrease parameter of the brightness information, not by the above method. The shadow effect can be obtained.

An image conversion apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of an image conversion apparatus in a first embodiment of the present invention.
In FIG. 1, 1b is a brightness conversion unit A and 1c is a brightness conversion unit B.
The other parts are the same blocks as in FIG.

The operation of the image conversion apparatus configured as described above will be described below with reference to FIGS. 1 and 2.

First, the conversion address generation device 11 generates a pixel coordinate value 12 on the new image plane according to the given three-dimensional geometric structure expression, coefficient, position, direction and viewpoint position, and screen position,
The point coordinate value 13 on the original image plane corresponding to the pixel coordinate value 12 on the new image plane and the local reduction rate 18 of the original image are output.
The coordinate correspondence memory 14 stores the point coordinate value 13 on the original image plane by using the pixel coordinate value 12 on the new image plane for address designation. The reduction rate memory 19 stores the local reduction rate 18 of the original image.

The two-dimensional adaptive filter 1a removes high frequency components while changing the local filter characteristics according to the contents of the reduction ratio memory 19. The luminance conversion unit A1b performs the operation of the following table on the output of the two-dimensional adaptive filter 1a according to the local reduction ratio, and writes it in the image memory 17.

However, Under the control of the write address control device 16, the image memory 17 sequentially stores the original image whose brightness has been manipulated by the brightness conversion unit A1b in accordance with the local reduction ratio. Read address controller
Reference numeral 15 is an image memory 17 according to the point coordinate values on the original image plane extracted from the coordinate correspondence memory 14 at the timing of the new image.
The image data of the original image is read from the brightness calculation unit B1c according to the new image coordinate value (x, y) used by the read address control device 15 to extract the read address from the coordinate corresponding memory. The coefficients Kx (x) and Ky (y) are obtained, and the luminance Ys is calculated by the following equation using these coefficients.

Ys = Kx (x) * Ky (y) * Y The new image obtained by the above equation is a video with a pseudo shadow added according to the pixel position coordinate value on the new image.

The shades produced by the brightness conversion device A1b and the brightness conversion device B1c can be combined to add a pseudo shadow when light is applied from an oblique direction.

EFFECTS OF THE INVENTION As described above, the present invention changes the luminance of the corresponding pixel according to the pixel position coordinate value on the new image and the luminance conversion unit A capable of changing the luminance according to the local reduction ratio of the shape. By having the brightness conversion unit B capable of performing the above, it is possible to realize an image conversion device that can add a pseudo shade when light is obliquely applied.

[Brief description of drawings]

FIG. 1 is a block diagram of an image conversion apparatus according to an embodiment of the present invention, FIG. 2 is a graph display of luminance conversion coefficients in an embodiment of the present invention, and FIG. 3 is a block diagram of a conventional image conversion apparatus. is there. 11 …… Conversion address generation device, 12 …… New image plane pixel coordinate value, 13 …… Original image plane point coordinate value, 14 …… Coordinate corresponding memory, 15 …… Read address control device, 16 …… Write address Control device, 17 ... Image memory, 18 ... Local reduction ratio of original image, 19 ... Reduction ratio memory, 1a ... Two-dimensional adaptive filter, 1b ... Luminance conversion unit A, 1c ... Luminance conversion Part B. 21 ... New image plane coordinate system, 22 ... Luminance conversion coefficient (x direction), 23 ... Luminance conversion coefficient (y direction). 31 …… Conversion address generator, 32 …… Pixel coordinate value on new image plane, 33 …… Point coordinate value on original image plane, 34 …… Coordinate corresponding memory, 35 …… Read address control device, 36 …… Write address Control device, 37 ... Image memory, 38 ... Local reduction ratio of original image, 39 ... Reduction ratio memory, 3a ... Two-dimensional adaptive filter.

Claims (1)

[Claims] 1. A new image is generated by using a read address calculated according to a given three-dimensional geometric structure expression, coefficient, position, direction and viewpoint position, and screen position for reading from an image memory, An image conversion apparatus having a two-dimensional adaptive filter unit capable of changing the characteristics of a filter according to a local reduction rate of a shape,
An image having a brightness conversion unit A capable of changing the brightness according to the reduction ratio and a brightness conversion unit B capable of changing the brightness of the corresponding pixel according to the pixel position coordinate value on the new image. Converter.