JPS63296089A - Image display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an image display device.

[Conventional technology]

As a digital image display device, CAD (Computer Aided Design)
2. Description of the Related Art Graphic display devices used in 1ded design, etc., and still image display devices that display still images using large-capacity storage means such as magnetic disks and optical disks are generally known. For example, Japanese Patent Application Laid-Open No. 58-225784 describes an example of such a device.

In general, digital image display devices have a configuration in which one screen is divided into pixel units (sampled), and the color information of each pixel is stored as digital data and displayed by sequentially reading it out. It becomes.

For this reason, unnaturalness may occur in the displayed image due to digitization, and in order to eliminate this, it is necessary to increase the number of pixels per screen and the number of bits per pixel. must be done. For example, N.T.
To display at the same resolution as an SC television,
One screen consists of 720 pixels horizontally and 480 pixels vertically, a total of 350,000 pixels, and each pixel is 24 bits (RG
It is necessary to use data of 8 bits each for the three primary colors of B, and therefore approximately 1 megabyte of data is required for each screen. In this way, image display requires a large amount of data.

However, this means that by increasing the amount of data, it is possible to freely improve the definition and color expressiveness of images. In addition, digital image display devices use analog signals and are more compatible with digital devices such as microcomputers than those using analog signals.
It is also easy to implement random access and complex video signal processing (for example, image overlaying and color conversion).

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, as an image output device, a display screen such as a cathode ray tube display device is used as a two-dimensional (i.e.
Since a display device that is a flat surface is used, the following problems arise when effectively displaying a three-dimensional object (for example, a sculpture).

A three-dimensional view is well known as a three-dimensional display method, but this method has problems in terms of ease of intuitive understanding.

Therefore, the best way to display a three-dimensional image is to freely rotate the object and display it. However, this requires an extremely large amount of data.

For example, if one image is displayed every time the image is rotated by 30 degrees, the image data for 12 images can be obtained by just rotating the image horizontally (that is, rotating it left or right around a certain vertical axis). Requires. Further rotation in the vertical direction (i.e., rotation up or down around a certain horizontal axis).
If you add , image data for 144 images is required (that is, there are 12 ways of rotation in the horizontal direction and 12 ways in the vertical direction, so 144 images of 12 x 12 are required).
. What you need to be careful about here is that the images obtained will differ depending on the order in which the rotations are performed.
For example, an image obtained by rotating an object 90 degrees upward from its original position and an image obtained by rotating an object 90 degrees to the right from its original position and then 90 degrees upward are both images of the original position. The images are obtained by viewing objects at the same position from directly above, but their orientations are different.

Taking these points into account, if we attempt to display images obtained by rotating them in any direction and in any order, the amount of data required will be enormous, resulting in an increase in the storage capacity of the recording medium. , data transfer time and access time are increased, and there are problems in all respects when putting it into practical use.

In addition, although only images rotated every 30'' were considered here, the amount of data required would further increase in order to rotate more smoothly and continuously.

The purpose of the present invention is to solve the problems of the prior art described above,
An object of the present invention is to provide an image display device capable of displaying an image obtained by rotating a solid object in an arbitrary direction and at an arbitrary angle with a smaller amount of data.

[Means for solving problems]

In order to achieve the above object, the present invention prepares two or more images obtained by viewing a certain solid from different directions,
Storage means for storing color information and depth information of each pixel in each image in a storage position corresponding to the position of each pixel in the image, and color information of each pixel stored in the storage means. and depth information for each image one by one from the storage means, and information on the position of each pixel within the image obtained from the read depth information of each pixel and the storage position of the depth information. A calculation means that performs a desired three-dimensional transformation on each image to obtain new depth information and position information for each pixel in the image, and color information for each pixel for one image. a frame memory capable of storing depth information for each pixel, and depth information for each pixel newly obtained by the calculation means and color information for each pixel read out by the reading means, sequentially for each image; and writing means for writing, based on information G of the position of each pixel in the image newly obtained by the calculation means, into a storage position of the frame memory corresponding to the position, In an image display device that reads and displays color information written in a frame memory, the writing means, when writing the depth information and color information into the frame memory, starts the writing from a storage position in the frame memory to which the information is to be written. (hereinafter referred to as stored depth information)
and compares the read memory depth information with the depth information to be written, and only when the degree of depth of the depth information is smaller than the depth degree of the memory depth information, the depth information and color information are It is designed to write the following.

[Effect]

The storage means stores color information and depth information (Z coordinate value) of each pixel in two or more images obtained by viewing a certain solid from different directions. Note that their storage positions are the positions (X) of each pixel within the image.

Y coordinate).

The information stored in the storage means is read out one image at a time by the reading means.

The calculation means calculates depth information (Z
information on the position of each pixel within the image obtained from the storage position of the depth information (coordinate value) (X.

Y-coordinate value), the desired three-dimensional transformation (rotation, enlargement/reduction, translation) is performed for each image.

(perspective transformation, etc.).

The depth information (Z coordinate value) of each pixel newly obtained by the calculation means and the color information of each pixel read out by the reading means are sequentially written for each image by the writing means, Based on the information on the position of each pixel in the image (values of X and Y coordinates) newly obtained by the calculation means, the information is written into the storage position of the frame memory corresponding to the position.

However, depending on the shape of the solid, by performing the three-dimensional transformation described in ``2'', the part that was previously visible may be hidden behind other parts, or it may become hidden behind the solid. There may be cases where it gets lost. Therefore, in the present invention, when writing the depth information and color information to the frame memory, the writing means starts from the storage position of the frame memory to which the depth information and color information should be written. read out the information),
The read memory depth information is compared with the depth information to be written, and the degree of depth of the depth information (
That is, hidden point processing is performed by writing the depth information and color information only when the depth (Z coordinate value) is smaller than the degree of depth of the stored depth information (that is, the Z coordinate value). .

That is, by this hidden point processing, only the color information of pixels located closer to the front is left as memory in the frame memory. By doing this, when all the images are written into the frame memory, the closest image is stored in the frame memory. Thereafter, by reading out the color information written in the frame memory, a desired image can be displayed.

Therefore, according to the present invention, as long as several images of the same solid are viewed from different directions are prepared, two or more of these images can be used to view the solid in any direction. Since it is possible to freely create and display images obtained by rotating the image at any angle, the number of images that need to be prepared in advance is much smaller than in the past, and the amount of data required is significantly reduced. Can be done.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram for explaining the operation of the embodiment of FIG.

In FIG. 1, 101 is an input terminal into which image data is input, 102 and 103 are input terminals into which three-dimensional conversion parameters are input, 104 is a switch to switch the destination of the input image data, and 105 and 110 are input terminals. 106 and 110 are read control circuits for reading the written image data from the memories 112 and 114, and 107 and 109 are three-dimensional conversion parameters. an arithmetic circuit that performs a three-dimensional transformation operation based on the
8 is a hidden point processing circuit that performs hidden point processing using the memory 113; 115 and 117 are display readout circuits that read data for display from the memory 112 and 113 and output it as a display signal; and 116 is a switch that switches the display signal. , 118 are display signal output terminals.

Next, the operation of this embodiment will be explained with reference to FIG. As an example, consider the case where the T-shaped block 1 shown in FIG. 2 (1) is displayed. In addition, X, Y in Fig. 2 (1)
, Z coordinates are set as shown in the figure.

First, images of this T-shaped block 1 viewed from several directions are stored in a storage device (not shown in FIG. 1).

For example, as shown in FIG. 2 (1), there is an image when the T-shaped block 1 is viewed from the direction of arrow A (front), an image when viewed from the direction of arrow B (top), and an image when viewed from the direction of arrow B (top). Assuming that the image seen from the direction (side) of C is to be memorized,
The respective images become images a, b, and c as shown in FIG. 2 (2).

At this time, in each image a, b, c, x, y
, z are determined as shown in the figure.

That is, each image a, b, and c is considered to be an orthogonal projection of the object (T-shaped block 1) onto the XY plane, and the Z axis is taken perpendicular to the plane of the paper. Therefore, x shown in Figure 2 (1)
, y, z coordinates, only image a in Figure 2 (2) has the same coordinates as those in Figure 2 (1).
The coordinates will be completely different.

By the way, the images s and c shown in FIG. 2(2) can be considered in the following way in addition to the above-mentioned viewpoint. That is, the image shown in FIG. 2 (2) is an image of the T-shaped block 1 shown in FIG. 2 (1) facing downward 90 around the X axis shown in FIG.
This is an image when viewed from the direction of arrow A (front) after rotating the T-shaped block 1. Left around the axis 9
It can also be considered that the image is viewed from the direction of the arrow (front) after being rotated by 0°. In this case, the second
The respective coordinates in images a, b, and c shown in FIG. 2 (2) are exactly the same as the coordinates shown in FIG. 2 (1).

In addition, when storing the images in the storage device (not shown in FIG. 1), each of the images a, b, and c shown in FIG. It is assumed that only information is stored. Here, the color information represents the color of each pixel constituting the image, and each color information is represented as a color code. On the other hand, depth information refers to the Z coordinate (in this case, Z
The coordinates are coordinates based on each Z axis shown in FIG. 2 (2). ) represents the value of

Now, next, let's move on to the storage device (first
(not shown in the figure), the image data (that is, the color information and depth information of each pixel) of the image a shown in FIG. 2(2) is read out. The read image data is input to the input terminal 101.
After passing through the switch 104, the data is written into the memory 112 by the write control circuit 105.

Here, the memory 112 is capable of storing information equivalent to one image of each image shown in FIG. 2 (2), and each address in the memory can store information corresponding to one image of each image shown in FIG. 2 (2). The coordinates of the position of each pixel (X.

There is a one-to-one correspondence with the Y coordinate). Color information and depth information can be stored in bare form at each address. Therefore, from the storage device (not shown in FIG. 1) described above, the color information and depth information (Z coordinate value) of image a shown in FIG. 2 (2) are stored in pairs, pixel by pixel, for example If the data is read in order from left to right, from top to bottom, and written in exactly the same order in the memory 112, as in the screen scanning of a television receiver, for example, as shown in FIG. Color information and depth information of pixel α in image a shown in (2) 2. is written to the address X++)'+ of the memory 112, assuming that the position of the pixel α on the image a, that is, the values of the X and Y coordinates, are X++)'+. As a result, information on the position of each pixel on image a (i.e., X, Y coordinate values) is obtained from the address of the memory 112, and color information and depth information (i.e.,
It can be seen that the value of the Z coordinate is determined from the information stored at that address.

Next, the image stored in this memory 112 (i.e.
When displaying the image a) shown in FIG. 2(2), only the color information in the memory 112 is displayed by the readout control circuit 115.
If we consider only this color information, which is read out sequentially, this is the same as data stored in a normal frame memory or the like. ) is displayed by outputting it from the display signal output terminal 118 via the switch 116. At this time, the display readout control circuit 115 creates a synchronization signal or the like as necessary and outputs it together with the display signal.

Next, consider the case where it is desired to display the T-shaped block l as shown in FIG. 2 (5).

First, the image shown in FIG.
The image data of image a shown in a) is read out by the readout control circuit 1.
06, the data is sequentially read from the memory 112.

At this time, information on the position of each pixel on the image, that is, the X and Y coordinates, is obtained from the readout address, and is sent to the arithmetic circuit 107 together with the Z coordinate and color code (color information) that are the readout image data. In the arithmetic circuit 107, the manually generated
, Y, and Z coordinates, three-dimensional coordinate transformation (i.e., rotation) is performed in advance according to the three-dimensional transformation parameters input from the input terminal 102 to obtain new X, Y, and Z coordinates, and the coordinates are sent. The hidden point processing circuit 1 together with the color code (the arithmetic circuit 107 does not perform any processing on the color code)
Output to 08.

That is, in the arithmetic circuit 107, the image a shown in FIG.
As shown in Figure 2 (3), in the order of the white arrows, first,
The image is rotated 30 degrees leftward about the Y axis, then rotated 30 degrees downward about the X axis, and the coordinates are transformed in order to obtain the image a' shown in FIG. 2 (4).

Furthermore, as such three-dimensional transformation, four-dimensional transformation using homogeneous coordinates is possible.
This is performed by matrix calculation using a ×4 matrix. for example,
To rotate pixel α to the left around the Y axis by ψ,
The X, Y, Z coordinates of pixel α are XI * Yt + z
+,...(1) By matrix operation according to equation (1), new x of pixel α,
As y, z coordinates, Xl'+)I, °, 2. Get °.

Matrix operations using a 4x4 matrix using these homogeneous coordinates allow for rotation, expansion, and reduction.

It is possible to perform various operations such as parallel translation and i3-view conversion. Note that the 4×4 transformation matrix is given as a three-dimensional transformation parameter from the input terminal 102, as described above.

Next, in the hidden point processing circuit 108, the input x, y,
The color code (color information) and the Z coordinate value (depth information) are written into the memory 113 while performing hidden point processing using the z coordinate.The hidden point processing will be explained in detail later, but this In this case, since nothing has been previously written in the memory 113, the image data (i.e., color information and depth information) of the image a' shown in FIG. 2(4) is written into the memory 113 as is.

Note that the memory 113 has the same configuration as the memory 112 described above, and the writing method is the same as that described above, so that the color information of a certain pixel β in the image a' shown in FIG. The depth information z2 is written to the address Xz+yz of the memory 113, assuming that the position of the pixel β on the image a', that is, the values of the X and Y coordinates are Xz+yz.

Next, after switching the switch 104 shown in FIG. 1 to the opposite side, the image data of the image shown in FIG. 2 (2) is read from the aforementioned storage device (not shown in FIG. 1). . The read image data is input from the input terminal 101, passes through the switch 104, and then is sent to the write control circuit 111.
is written into memory 114 in the same manner as described above.

Thereafter, the written image data is sequentially read out by the readout control circuit 110. At this time, in the same manner as described above, the X and Y coordinates are obtained from the read address and sent to the arithmetic circuit 109 together with the read image data (that is, the color code and the Z coordinate value).

The arithmetic circuit 109 performs three-dimensional coordinate transformation on the input X, Y, and Z coordinates according to the three-dimensional transformation parameters inputted in advance from the input terminal 103 to obtain new x, y, and z coordinates. and outputs it to the hidden point processing circuit 108 together with the sent color code.

At this time, the three-dimensional transformation parameters manually entered in advance from the input terminal 103 are different from the three-dimensional transformation parameters input from the input terminal 102 described above, as shown in FIG.
Three-dimensional transformation parameters must be prepared so that the transformed image shown in 2) and the image a' shown in Figure 2 (4) look like images viewed from the same direction. No.

To do this, first transform the image shown in Figure 2 (2) so that the coordinate axes match those of image a shown in Figure 2 (2), and then image a second
The same conversion as when converting into image a' shown in FIG. 4 may be performed.

That is, the arithmetic circuit 109 first rotates the image shown in FIG. 2 (2) upward by 90'' around the X axis in the order of the white arrows as shown in FIG. Rotate 30@ to the left around the axis, and further 30@ to the downward direction around the X-axis.
By doing so, the image b' shown in FIG. 2(4) is obtained.

Next, in the hidden point processing circuit 108, in the same manner as described above,
The color code and the Z coordinate value are written into the memory 113 while performing hidden point processing using the input x, y, and z coordinates. As a result, both the image data of image a' and the image data of image b' shown in FIG. This means that the composite image b' has been written.

Next, the switch 104 shown in FIG. 1 is switched as shown, and the second
The image data of the image C shown in FIG.
After being once written to , it is read out and sent to the arithmetic circuit 107 along with the X and Y coordinates obtained from the read address.

The arithmetic circuit 107 performs three-dimensional transformation on the input x, y, and z coordinates according to the three-dimensional transformation parameters newly input from the input terminal 102 to obtain new X, Y,
Obtain the Z coordinate and send it to the hidden point processing circuit 10 along with the sent color information.
Output to 8. That is, the image C shown in FIG. 2 (2) is first rotated 60 degrees to the right around the Y axis, and then rotated 3 degrees downward around the X axis in the order of the white arrows as shown in FIG. 2 (3).
By rotating it by 0°, an image C' shown in FIG. 2 (4) is obtained.

Next, in the hidden point processing circuit 108, the manually generated x, y,
Hidden point processing is performed using the z coordinate.

Now, hidden point processing will be explained.

First, from the input X and Y coordinate values, the address in the memory 113 corresponding to the coordinate values is found, and the Z coordinate value stored at that address is read out from the memory 113. Next, the magnitude relationship between the Z coordinate value read from this memory 113 and the Z coordinate value input from the arithmetic circuit 107 is compared.

If the former value is larger than the latter value, the color code (sensuality II) and Z coordinate value input from the arithmetic circuit 107 are written to the address of the memory 113, and the former value is changed to the latter value. If it is smaller, nothing is written and it is left as is.The above processing is performed for each pixel in the order manually input by the arithmetic circuit 107.

Therefore, for example, the arithmetic circuit 107 calculates x and y of the pixel T in the image C' shown in FIG. 2(4).

Assuming that the value Xz+)'z+z is input as the Z coordinate, the hidden point processing circuit 108 finds the address Xz+)'z in the memory 113 and calculates the Z coordinate value 2z stored there, that is, This is shown in Figure 2 (4
) in the image a' shown in pixel β(X.

It is located at Y coordinates Xt* and Yz. ), which is read from the memory 113.

Then, this read value z2 and the value 2. input from the arithmetic circuit 107 are combined. When compared with z8, z8 is 2. In other words, this means that even if they are at the same position on the image (i.e., on the display screen), when considering the depth, pixel β is located further in front than pixel T. represents. Naturally, the pixel β located closer to the front needs to be displayed preferentially, so the Z coordinate value 2° and color information regarding the pixel γ input from the arithmetic circuit 107 are not written to the memory 113. Disappear.

As described above, the hidden point processing circuit 108 writes the color information and the Z coordinate value input from the arithmetic circuit 107 into the memory 113 while performing hidden point processing.

As a result, the memory 113 stores image data of image a' shown in FIG. 4(4), image data of image b', and image C'.
This means that the image data shown in Figure 2 (5), which is a composite image of image a', image b', and image C', has been written when looking at the image as a whole. . It should be noted that, as a matter of course, by the hidden point processing described above, the image C' corresponding to the shaded area shown in FIG. 2 (5) is
image data will be deleted.

In this way, the target image 2 (
Since the complete data of the image shown in 5) has been obtained, after switching the switch 116 to the opposite side from the one shown in the figure, only the color information is read out from the memory 113 by the display readout circuit 117, and then the color information is read out from the output terminal 118 via the switch 116. By outputting, the desired image is displayed.

By the way, as mentioned earlier, the hidden point processing circuit 108
The image a and L1 image b' shown in FIG. 2 (4) are stored in the memory 11.
Hidden point processing is also performed when writing to the memory 113, but the memory 113 is in an initial state in advance, for example, with the color information set to "black" and the Z coordinate value set to the maximum (i.e., the deepest position). By storing all addresses in the image a'.

The color information and Z coordinate values of both image b' are written into the memory 113 as they are without being erased.

In addition, in the explanation of this embodiment, the three-dimensional transformation in the arithmetic circuits 107 and 109 will be explained as follows for ease of explanation.
Although the explanation is that it is performed in two or three times, it is actually done in one step because the three-dimensional transformation is performed by matrix operations as mentioned above.
Only one conversion is required, and the amount of calculation in the calculation circuits 107 and 109 does not increase.

As described above, according to this embodiment, three-dimensional transformation is performed on each image based on two or more images, and the parts that cannot be obtained by the transformation are supplemented with each other's images and combined. This allows you to display an image obtained by rotating a solid object in any direction and at any angle. Furthermore, even if an overlapping portion occurs due to the combination, the above-described hidden point processing eliminates the problem.

Next, FIG. 3 is a block diagram showing another embodiment of the present invention.

In FIG. 3, parts that are the same as those shown in FIG. 1 are given the same reference numerals. Others, 201°202.20
6 is a changeover switch, 203, 204, 205 are memories, and 207 is a display readout circuit.

In order to display an object with a very complex shape, the number of images that must be written to the memories 112 and 114 in FIG. 1 increases, so in order to cope with this, in this embodiment,
Instead of the memory 114 shown in FIG. 1, three memories (memories 203 to 205) are used.

Now, the operation of this embodiment will be explained.

First, image data (color information and depth information) of a first image inputted from the input terminal 101 is written into the memory 112 by the write control circuit 105 via the switch 104 . Next, the switch 104 is switched to the opposite side as shown in the figure, and the image data of the second image that is subsequently input is written into the memory 203 by the write control circuit 111. next,
The switch 201 is switched to write the image data of the third image that is subsequently input into the memory 204, and the switch 201 is further switched to write the image data of the fourth image that is subsequently input to the memory 205.

Next, the read control circuit 106 controls the memory 112
The image data is read out from 3 in the arithmetic circuit 107.
After performing the dimensional transformation, the hidden point processing circuit 108 performs hidden point processing while writing to the memory 113. Similarly, while sequentially switching the switch 201, the readout control circuit 110 sequentially reads image data from the memories 203 to 205, performs three-dimensional transformation in the arithmetic circuit 109, and then performs hidden point processing in the hidden point processing circuit 108. The data is written to the memory 113 while the process is being performed.

In the arithmetic circuit 109, desired three-dimensional transformation parameters are input from the input terminal 103 at the same time as the switch 201 is switched, and three-dimensional transformation corresponding to the second to fourth images is performed.

Thereafter, the switch 206 is switched to the opposite side as shown in the figure, and the display reading circuit 207 reads only the color information from the memory 113 and outputs it from the output terminal 118, thereby displaying the desired image.

Note that in this embodiment, the display readout circuit 207 is unified,
The display is switched by switching between the output of the memory 112 and the output of the memory 113.

〔Effect of the invention〕

According to the present invention, as long as several images of the same solid are viewed from different directions are prepared, two or more of these images can be used to move the solid in any direction. Since it is possible to freely create and display images obtained by rotating the angle of , the number of images that need to be prepared in advance is much smaller than in the past, and the amount of data required is significantly reduced.

In addition to rotation, the solid object can also be enlarged or reduced.

Images obtained by parallel translation and perspective transformation can also be displayed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining the operation of the embodiment of FIG. 1, and FIG. 3 is a block diagram showing another embodiment of the present invention. , is. Explanation of symbols 105.111...Writing control circuit, 106
゜110... Readout control circuit, 107, 10
9... Arithmetic circuit, 108... Hidden point processing circuit, 112°113.114... Memory,
115,117... Display readout circuit agent Patent attorney Akio Namiki II Figure 3

Claims (1)

[Claims] 1. Prepare two or more images obtained by looking at a certain solid from different directions, and one by one, color information and depth information of each pixel in those images are added to the image of each pixel. a reading means for sequentially reading color information and depth information of each pixel stored in the storage means for each image from the storage means; A desired three-dimensional transformation is performed for each image on the depth information of each pixel and the information on the position of each pixel in the image obtained from the storage position of the depth information, and a new a frame memory capable of storing color information and depth information of each pixel for one image; The depth information of each pixel read out by the reading means and the color information of each pixel read out by the reading means are sequentially processed one image at a time, and the information of the position of each pixel in the image newly obtained by the calculation means is processed. an image display device for reading and displaying color information written in the frame memory, the image display device comprising: writing means for writing to a storage position of the frame memory corresponding to the position based on the color information, the writing means for reading and displaying color information written in the frame memory; , when writing the depth information and color information to the frame memory, read out the depth information (hereinafter referred to as stored depth information) stored in the frame memory from the storage position to which it should be written; The stored depth information and the depth information to be written are compared, and the depth information and color information are written only when the degree of depth of the depth information is smaller than the degree of depth of the stored depth information. An image display device characterized by: