JP2000020698A - Method and device for creating three-dimensional image file, method and device for generating image and computer-readable recording medium in which program to make computer execute the methods is recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy and high speed access to a three-dimensional image file. SOLUTION: Original three-dimensional image data S0 is converted into plural pieces of multiple resolution three-dimensional image data S1 having mutually different resolution in a multiple resolution resolving means 2. Pieces of the three-dimensional image data S1 for each resolution are divided into cubes in a cube dividing means 3. A three-dimensional image file F is created by making the resolution correspond to the cube to be included in resolution in a file creating means 4 and is recorded in a recording medium 5. When the image of a specified slice surface in specified resolution is required, the image of the slice surface is generated by only making access to the cube including the slice surface in the resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for creating a three-dimensional image file for creating a three-dimensional image file from original three-dimensional image data, a method and an apparatus for generating an image, and a method for causing a computer to execute these methods. The present invention relates to a computer-readable recording medium on which a program is recorded.

[0002]

2. Description of the Related Art As a format for storing image data, JPE is used.
There are various formats such as G, GIF, and TIFF. Recently, a format has been proposed in which image data is hierarchically decomposed for each resolution or density resolution, and data (hierarchical data) for each layer is encoded and stored in a compressed form. ing. Specifically, this storage format decomposes image data into hierarchical data for each of a plurality of resolutions or density resolutions by wavelet transform or the like,
The decomposed hierarchical data for each resolution or each density resolution is encoded in the hierarchical order, compressed and stored as one file.

This storage method has the following features.

(1) D used in conventional JPEG
Unlike the CT (Digital Cosine Transfer) method, since image data is not processed for each block, artifacts such as block distortion do not occur.

(2) Since the image data is hierarchically encoded, only the information of the necessary resolution at the time of transferring the image data needs to be transferred, and efficient image transfer is possible.

(3) Since image data is decomposed into multiple resolutions or multiple density resolutions, various types of image processing such as frequency emphasis processing can be performed relatively easily.

(4) Simultaneous decomposition of color space and frequency by multi-resolution analysis is possible, and orthogonal transformation is performed in a wide range for a low frequency region that greatly affects coding efficiency, and is performed for a high frequency region. Since orthogonal transformation can be performed in a narrow range, even if quantization noise is generated around an edge in an image, it is possible to suppress the spread in color space.
For this reason, noise is not easily perceived.

[0008] Further, a file format capable of recording a plurality of data having different properties in one file has been proposed, such as a FlashPix file proposed by Eastman Kodak Company.
It is also possible to store hierarchical data decomposed into multiple resolutions or multiple density resolutions in a Pix standard file.

Further, an image is spatially divided into a plurality of tile-shaped areas, and image data in a file format encoded so as to be accessible for each image data in each area is created. Such a file format requires a long time to rearrange data if the images are arranged in units of scanning lines, for example, when a part of one image is enlarged and displayed and the entire image is not required. It is possible to individually access only a desired area. When reproducing the entire image data in such a file format, the data is accessed for each area and the entire image is reproduced.

On the other hand, it is possible to easily draw a three-dimensional image using computer graphics or the like. Although an image by computer graphics is three-dimensional, since a three-dimensional image is generated from vector information, it is easy to draw with a changed resolution, and the image is tiled as described above. It is easy to divide.

Further, there is a three-dimensional image called a distance image. This distance image is composed of a two-dimensional image and depth information of each image. Although it is three-dimensional, a side channel is added to each channel of the two-dimensional image and depth information is recorded in the side channel. It is. Therefore, by converting a two-dimensional image into a multi-resolution space and adding a side channel on which depth information is recorded to an image of each resolution, it is easy to store the images in a multi-resolution hierarchy. It is also possible to divide each two-dimensional image into a plurality of tiled areas. Therefore, by decomposing the three-dimensional image and the distance image drawn by computer graphics into a multi-resolution space and dividing the image of each resolution into tiles, the required resolution or the necessary area of the three-dimensional image can be easily adjusted. And it can be accessed at high speed.

[0012]

In the medical field, there are three-dimensional images that continuously hold CT slice planes and three-dimensional images that hold MRI images three-dimensionally. Such a three-dimensional image is composed of complete three-dimensional image data having values at all points in the xyz three-axis directions. For such a three-dimensional image,
The image is sliced in the Z-axis direction at predetermined intervals, and
It is conceivable that a two-dimensional image is generated, a two-dimensional image is converted into a multi-resolution space, and a three-dimensional image file is stored by being divided into tiles.

However, there is no problem when the required image exists on the slice plane, but when the required image exists at an intermediate position of the slice plane, an image representing the image of the slice plane close to the required image position is obtained. It is necessary to generate an image of a necessary plane from the data by a proportional calculation or the like. Also, 3
In order to generate a desired slice plane as an image having a lower resolution than the original image when the three-dimensional image data is held in a complete state, once all the three-dimensional image data is read out and the slice plane is read out. Extract the data of
This needs to be further reduced. Therefore, in any case, the necessary images included in the three-dimensional image data cannot be easily and quickly accessed.

The present invention has been made in view of the above circumstances, and provides a method and apparatus for creating a three-dimensional image file that can create a three-dimensional image file so that necessary parts in a complete three-dimensional image can be accessed easily and at high speed. It is an object of the present invention to provide a computer-readable recording medium on which a program for causing a computer to execute an image generation method and apparatus and a three-dimensional image file creation method is recorded.

[0015]

According to the present invention, there is provided a three-dimensional image file creating method for creating a three-dimensional image file from original three-dimensional image data having a value corresponding to each point on three-dimensional coordinates. In the creation method, the original three-dimensional image data is converted into a multi-resolution space to obtain a plurality of multi-resolution three-dimensional image data having different resolutions, and each of the multi-resolution three-dimensional image data is converted into a cubic image composed of a plurality of cubic regions. Split into data,
A three-dimensional image file is created by associating the resolution of each of the multi-resolution three-dimensional image data with the cubic image data included in the multi-resolution three-dimensional image data at that resolution.

A three-dimensional image file creating apparatus according to the present invention is for implementing the three-dimensional image file creating method according to the present invention, and converts the original three-dimensional image data into a multi-resolution space to have different resolutions. Multi-resolution conversion means for obtaining a plurality of multi-resolution three-dimensional image data; division means for dividing each of the multi-resolution three-dimensional image data into cubic image data comprising a plurality of cubic regions;
File creating means for creating a three-dimensional image file by associating the resolution of each of the multi-resolution three-dimensional image data with the cubic image data included in the multi-resolution three-dimensional image data at that resolution. It is assumed that.

An image generating method according to the present invention is an image generating method for generating a two-dimensional image from a three-dimensional image file created by the three-dimensional image file creating method according to the present invention. Is read from the three-dimensional image file, and the two-dimensional image is generated based on the data included in the read cubic region.

An image generating apparatus according to the present invention is an image generating apparatus for generating a two-dimensional image from a three-dimensional image file created by the three-dimensional image file creating apparatus according to the present invention, wherein data necessary for the two-dimensional image is provided. And a generating means for generating the two-dimensional image based on the data contained in the read cubic region. is there.

The three-dimensional image file created according to the present invention may be provided by recording it on a recording medium.

Further, a program for causing a computer to execute the processing performed in the three-dimensional image file creating method or the image generating method may be provided by being recorded on a computer-readable recording medium.

[0021]

According to the method for creating a three-dimensional image file according to the present invention, the original three-dimensional image data is converted into a multi-resolution space to obtain a plurality of multi-resolution three-dimensional image data. A three-dimensional image file is created by dividing the image into cubic image data composed of cubic regions and associating the resolution with cubic image data included in the multi-resolution three-dimensional image data of the resolution. That is, the multi-resolution three-dimensional image of each resolution is divided into a plurality of cubic regions and generated. For this reason, when an image of a desired surface in the original three-dimensional image data is required, by accessing only the cubic image data including the surface in the multi-resolution image data of the desired resolution, the image of the surface can be obtained. Can be generated. Therefore, it is possible to easily and quickly access the three-dimensional image data.

[0022]

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

FIG. 1 is a schematic block diagram showing a configuration of a three-dimensional image file creating apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the three-dimensional image file creating device according to the present embodiment creates a three-dimensional image file F from original three-dimensional image data S0 generated by the three-dimensional image data generating device 1, A multi-resolution decomposition means for converting the three-dimensional image data into a multi-resolution space to obtain a plurality of multi-resolution three-dimensional image data having different resolutions (represented by S1); Resolution of multiple resolution 3
Cube dividing means 3 for dividing the three-dimensional image data S1 into a plurality of cubes; the resolution of the multiresolution three-dimensional image data S1;
File creating means 4 for creating a three-dimensional image file F by associating with a cube included in the
Consists of

The three-dimensional image data generating device 1 is a device for forming measurement data by medical MRI as a three-dimensional image. In medical CT, a relative helical rotation is performed by a high-speed rotation of a radiation source and a movement of a bet of a subject. For forming a three-dimensional image of a subject using a two-dimensional surface sensor and a source for two-dimensionally irradiating the subject in medical CT.
Devices in which the obtained image data has a value at each point on the three-dimensional coordinates, such as a device that forms a three-dimensional image or a device that forms measurement data from a medical or industrial ultrasonic probe as a three-dimensional image. Can be

FD, M
Not only a medium for recording the three-dimensional image file F on the portable recording medium 5 such as O and ZIP, but also any other medium as long as digital data such as a hard disk and a memory can be recorded.

Next, processing performed in the three-dimensional image file creating apparatus according to the present embodiment will be described.
FIG. 2 is a flowchart showing processing performed in the three-dimensional image file creation device according to the present embodiment. First, the original three-dimensional image data S0 generated by the three-dimensional image data generation device 1
, Where the original three-dimensional image data S0 is converted to a multi-resolution space. The decomposition into the multi-resolution space is performed by simply thinning out the pixels of the original three-dimensional image data S0 every other pixel. Thus, the original three-dimensional image data S0 has the same resolution as the original three-dimensional image data S0, as shown in FIG.
solution1, Resolution2, which is 1/2 resolution, 1/4
Are converted into a multi-resolution space, such as Resolution3, and are decomposed into a plurality of multi-resolution three-dimensional image data S1 having different resolutions. In the decomposition into the multi-resolution space, the three-dimensional image data S1 having the lowest resolution is
It is repeated until it becomes the same size as one cube.
For example, if the original three-dimensional image data S0 is 1024 × 1024
With a resolution of × 1024 pixels, the size of one cube is 64 ×
In the case of 64 × 64 pixels, multi-resolution three-dimensional image data S
1 has five layers as shown in Table 1 below.

Table 1 Resolution1: 1024 × 1024 × 1024 Resolution2: 512 × 512 × 512 Resolution3: 256 × 256 × 256 Resolution4: 128 × 128 × 128 Resolution5: 64 × 64 × 64 Is divided into a plurality of cubes (step S2). Here, xy with one vertex as the origin in the multi-resolution three-dimensional image data S1 of each resolution.
Considering the z-coordinate system, coordinates (0,0,0)-(0,64,0)-(64,0,
0)-(0,0,64)-(0,64,64)-(64,0,64)-(64,64,0)-(64,64,6
Let the cube surrounded by 4) be Cube000. Similarly, coordinates (64 * X, 64 * Y, 64 * Z)-(64 * X, 64 * Y, 64 * Z + 64)-(64 * X, 64 * Y +
64,64 * Z)-(64 * X + 64,64 * Y, 64 * Z)-(64 * X, 64 * Y + 64,64 * Z + 6
4)-(64 * X + 64,64 * Y + 64,64 * Z)-(64 * X + 64,64 * Y, 64 * Z + 64)-
The cube surrounded by (64 * X + 64,64 * Y + 64,64 * Z + 64) is C
ubeXYZ. Accordingly, in the multi-resolution three-dimensional image data S1 shown in Table 1, as shown in FIG.
1 for lution5, 8 for Resolution4, 6 for Resolution3
Multi-resolution three-dimensional image data S1 of each resolution such as four is divided into cubes.

The multi-resolution three-dimensional image data S1 thus divided into cubes is stored in a file
In, the three-dimensional image file F is created by associating and structuring the resolution with the cube included in the multi-resolution three-dimensional image data S1 of that resolution (step S3). FIG. 5 shows the file format of the three-dimensional image file F created as described above. As shown in FIG. 5, the three-dimensional image file F includes Resolution1 to ResolutionX (in this embodiment,
Resolution5) storage. Under each storage, there are CubeXYZ streams corresponding to the number of cubes at each resolution. Note that in ResolutionX with the lowest resolution, the number of cubes is one, so the stream is C
ube000 only. 3 created in this way
The two-dimensional image file F is recorded on the recording medium 5 (Step S4).

Next, an image generating apparatus for generating an image from the three-dimensional image file F created as described above will be described. FIG. 6 is a schematic block diagram illustrating the configuration of the image generation device according to the present embodiment. As shown in FIG. 6, the image generating apparatus according to the present embodiment reads out three-dimensional image data at a desired position at a desired resolution from the three-dimensional image file F recorded on the recording medium 5 as described above. Image processing means 7 for generating reproduced image data S3 representing an image to be reproduced; a reproducing means 8 such as a monitor or a printer for reproducing the reproduced image data S3 generated by the image processing means 7; And input means 9 such as a keyboard, a mouse, etc., for inputting data.

Next, the processing performed in the image generating apparatus according to the present embodiment will be described. In the present embodiment, the reproducing means 8 is a monitor having a relatively low resolution, and the original three-dimensional image data S0 is 1024 × 1024 ×
When the resolution is 1024, an image on a slice plane of Z = 70 at a resolution of 256 × 256 × 256 is displayed. First, the operator inputs from the input unit 9 to the image processing unit 7 to display an image on a slice plane of Z = 70 at a resolution of 256 × 256 × 256. Thereby, the image processing means 7 reads out the image data according to the request from the recording medium 5. The reading of the image data is performed as follows.

First, the image processing means 7 performs a resolutio corresponding to a resolution of 256 × 256 × 256 in the three-dimensional image file F.
Access n3. Here, CubeX in Resolution3
The relationship between the stream of YZ and the value of the image data included in this stream in the Z-axis direction is shown in Table 2 below.

Table 2 Values of Z Stream 0-63 Cube ?? 0 64-127 Cube ?? 1 128-191 Cube ?? 2 192-255 Cube ?? 3 Therefore, the image processing means 7 calculates the value of Z = 70. Cube ?? 1 including
All the data of the cube of the stream (? Is a wild card) is read, and the data of the slice plane where Z = 70 is extracted from this cube to generate reproduced image data S3. Then, the reproducing means 8 reproduces the reproduced image data S3 as a visible image.

Here, as in the prior art, 1024 ×
If the original three-dimensional image data S0 having a resolution of 1024 × 1024 pixels is recorded as it is,
After reading out the dimensional image data S0, the data of the slice plane of Z = 70 is extracted and further reduced to a resolution of 256 × 256 × 256 pixels to reproduce the image. On the other hand, according to the present invention, the original three-dimensional image data S0 is converted into a multi-resolution space, and the multi-resolution three-dimensional image data S1 of each resolution is divided into a plurality of cubes. By reading only the cube containing the required slice plane at the resolution, the data of the required slice plane can be extracted. Therefore, the memory capacity for performing work in the image processing means 7 can be greatly reduced, and data can be read or transferred in a short time, so that access to three-dimensional image data can be easily and easily performed. Can be done at high speed.

In the above embodiment, the original three-dimensional image data S0 is reduced and decomposed into a multi-resolution space, but may be decomposed into a multi-resolution space by wavelet transform. In this case, a plurality of multi-resolution three-dimensional image data S1 having different resolutions can be obtained by performing a convolution operation on the wavelet basis functions in the xyz directions of the original three-dimensional image data S0. In addition to the wavelet transform, any method can be used as long as the image data can be decomposed into a multi-resolution space, such as a Laplacian pyramid and a sub-band transform.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating a configuration of a three-dimensional image file creation device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing processing performed in the three-dimensional image file creation device according to the embodiment;

FIG. 3 is a diagram showing a state in which original three-dimensional image data is converted into a multi-resolution space.

FIG. 4 is a diagram showing a state in which multiresolution three-dimensional image data is divided into cubes.

FIG. 5 is a diagram showing a file format of a three-dimensional image file.

FIG. 6 is a schematic block diagram illustrating the configuration of an image generation device according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 3D image data generation apparatus 2 Multi-resolution decomposition means 3 Cube division means 4 File creation means 5 Recording medium 7 Image processing means 8 Reproduction means 9 Input means

Claims (7)

[Claims] 1. A three-dimensional image file creating method for creating a three-dimensional image file from original three-dimensional image data having a value corresponding to each point on three-dimensional coordinates, wherein the original three-dimensional image data is stored in a multi-resolution space. Converting, obtaining a plurality of multi-resolution three-dimensional image data having different resolutions, dividing each of the multi-resolution three-dimensional image data into cubic image data including a plurality of cubic regions, And creating a three-dimensional image file by associating the cubic image data included in the multi-resolution three-dimensional image data with the resolution with the three-dimensional image file. 2. A three-dimensional image file creating apparatus for creating a three-dimensional image file from original three-dimensional image data having a value corresponding to each point on three-dimensional coordinates, wherein the original three-dimensional image data is stored in a multi-resolution space. A multi-resolution conversion means for converting to obtain a plurality of multi-resolution three-dimensional image data having different resolutions; a dividing means for dividing each of the multi-resolution three-dimensional image data into cubic image data comprising a plurality of cubic regions; File creating means for creating a three-dimensional image file by associating the resolution of the multi-resolution three-dimensional image data with the cubic image data included in the multi-resolution three-dimensional image data at the resolution. 3D image file creation device. 3. A computer-readable recording program for causing a computer to execute a three-dimensional image file creation method for creating a three-dimensional image file from original three-dimensional image data having a value corresponding to each point on three-dimensional coordinates. In a possible recording medium, the program converts the original three-dimensional image data into a multi-resolution space to obtain a plurality of multi-resolution three-dimensional image data having different resolutions from each other; A procedure of dividing the image into cubic image data composed of a plurality of cubic regions; a resolution of each of the multi-resolution three-dimensional image data; Creating an image file. recoding media. 4. A computer-readable recording medium which records a three-dimensional image file created from original three-dimensional image data having a value corresponding to each point on three-dimensional coordinates, wherein the three-dimensional image file is Converting the original three-dimensional image data into a multi-resolution space to obtain a plurality of multi-resolution three-dimensional image data having different resolutions; dividing each of the multi-resolution three-dimensional image data into cubic image data comprising a plurality of cubic regions; A computer-readable recording medium which is created by associating the resolution of each of the multi-resolution three-dimensional image data with the cubic image data included in the multi-resolution three-dimensional image data of the resolution. 5. An image generating method for generating a two-dimensional image from a three-dimensional image file created by the three-dimensional image file creating method according to claim 1, wherein a cubic region including data necessary for the two-dimensional image is provided. Read from the three-dimensional image file, and generate the two-dimensional image based on the data contained in the read cubic region. 6. An image generating apparatus for generating a two-dimensional image from a three-dimensional image file created by the three-dimensional image file creating apparatus according to claim 2, wherein the cubic area includes data necessary for the two-dimensional image. An image generating apparatus, comprising: a reading unit that reads the two-dimensional image from the three-dimensional image file; and a generating unit that generates the two-dimensional image based on the data included in the read cubic region. 7. A computer-readable recording recording a program for causing a computer to execute an image generation method for generating a two-dimensional image from a three-dimensional image file created by the three-dimensional image file creation method according to claim 1. A medium, wherein the program reads a cubic region including data necessary for the two-dimensional image from the three-dimensional image file, and reads the two-dimensional image based on the data included in the read cubic region. Generating a computer-readable recording medium.