JPH0217581A - Three-dimensional image processing device - Google Patents

Abstract

PURPOSE:To reduce the storage capacity by performing the three-dimensional projection processing after data compression. CONSTITUTION:Original image data of an object in a storage means 1 is inputted to a data compression processing means 3 through a binarized image data generating means 2 and is converted to run coordinates. Compressed data is inputted to a three-dimensional distance image generating means 4 to generate a three-dimensional distance image. Data related to the distance from a plane of view to the object is preliminarily stored in a distance data memory 8, and arbitrary distance data is read out based on designation from a distance designating means 9 to allocate corresponding data in the three-dimensional distance image generating means 4. A three-dimensional projection data generating means 5 subjects data read out from the three-dimensional distance image generating means 4 to shading or the like to generate three-dimensional projection data. This data is supplied to a CRT display device 7 through a display control means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a three-dimensional image processing apparatus for creating and processing three-dimensional projection data of an object, such as a human body.

(Prior Art) Maxillofacial surgery for cosmetic purposes has traditionally been performed in surgical operations. In this surgery, as shown in FIG. 5, the periosteum A1 is cut around the orbits Bl and B2 as shown by broken lines, and the vertical nasal bone B3 is peeled off with a periosteal stripper A2 as shown in FIG. As shown in FIG. 7, the orbital part B1.
B2 is moved to the center of the face. Orbital part B1. B
The gaps C1 and C2 created by the movement of the parts 2 are filled with parts obtained by cutting a part of the hip bone or the like.

In such maxillofacial surgery, positioning of the cutting site is extremely important in order to accurately move and fit the orbit. This is because it is necessary to move the orbital part to a predetermined area by cutting at least half the eye, and to fit it appropriately into the area.

Therefore, in order to support this maxillofacial surgery, there has been a strong desire to provide an image processing device that can simulate the surgery.

According to a conventional image processing device, it is possible to display a pseudo three-dimensional image based on a group of head slice images obtained by, for example, an X-ray CT device. This pseudo-three-dimensional image display uses voxel data obtained by appropriately interpolating data between slices of a group of slice images, and uses this data as a distance image (also called a depth image, surface image, or perspective image) at a desired viewing plane. A means of storing
This is done by displaying it on the T-display. The cutting site can be specified by setting a ROI (region of interest), and partial cutting of the image is performed by partially clearing voxel data by applying the ray tracing method in distance image creation. Furthermore, it is thought that the movement of the orbital part is possible by partial image movement processing (coordinate transformation processing).

(Problems to be Solved by the Invention) However, the conventional three-dimensional image processing apparatus as described above had the following problems.

(1) Conventionally, all of the binarized slice data was used as a voxel structure, resulting in an enormous storage capacity.

(2) Conventionally, 7-fin transformation was performed for each voxel, which required a large number of calculations, making it impossible to increase the projection speed.

(3) Due to the enormous storage capacity and increase in the number of calculations as described above, it has become difficult to process three-dimensional images.

The present invention has been made in view of the above circumstances, and a first object thereof is to provide a three-dimensional image processing device that can reduce storage capacity and increase projection speed.

A second object of the present invention is to provide a three-dimensional image processing device that facilitates cutting processing of three-dimensional images.

Nariko Mizo of the U Invention (Means for Solving the Problems) The present invention provides a three-dimensional image @ processing device that binarizes original image data and creates three-dimensional projection data based on this binarized data. a data compression means for compressing data by determining the coordinates of the end points of the object in the binarized data and storing this coordinate data; and a 3D line for creating a three-dimensional line based on the compressed data in relation to distance data. The present invention is characterized in that it includes an original distance image creating means and a three-dimensional projection data creating means for creating three-dimensional projection data from this three-dimensional distance image.

Further, in the present invention, data at a specific position in the distance data is selected and designated, and only three-dimensional projection data before or after this specific position is created.

Roughly speaking, the present invention performs image cutting processing on the three-dimensional projection data by specifying an arbitrary range of data in the distance data.

(Function) According to the above configuration, three-dimensional projection data can be created using compressed data without creating voxel data, so the storage capacity can be reduced. Furthermore, since projection data can be created simply by repeating compressed data and distance designation without performing affine transformation for each voxel, the number of calculations is reduced, and therefore the projection speed can be increased.

Cutting processing can be easily performed by simply specifying the coordinates of an arbitrary position in the three-dimensional projection data.

(Example) The present invention will be specifically explained below using Examples.

FIG. 1 is a block diagram showing one embodiment of the present invention.
2 is a storage means for storing original image data of an object; 2 is a storage means that binarizes the original image data for each slice using an arbitrary threshold value, and performs interpolation processing between slices to create binarized image data; 3 is a data compression processing means for compressing the binarized image data based on the compression principle described later and converting it into run coordinates; 4 is a three-dimensional image data generating means based on the compressed data; Means for creating a distance image; reference numeral 8 denotes a distance data memory (Z buffer) storing data regarding the distance (depth) of the object from the viewing plane;
Based on the designation from the distance designation means 9, arbitrary distance data is read out and the data is allocated to the corresponding position in the three-dimensional distance image creation means 4.

5 is a three-dimensional projection data creating means for creating three-dimensional projection data by applying shading etc. to the data read out from the three-dimensional distance image creating means 4 and storing it;
The three-dimensional projection data created in this manner is sent to a CRT display 7 via a display control means 6 for display.

Reference numeral 10 denotes a cutting processing means for specifying an arbitrary cutting surface in the three-dimensional projection data and cutting the image.

Next, the present invention will be described in detail with reference to FIGS. 2 to 4.

First, data compression processing will be explained with reference to FIGS. 2 and 3. One slice image (binarized image fs) SLt
For example, if objects Pt and P2 are included,
In the present invention, a plurality of lines Y1 to Yn are drawn in the Y-axis direction,
Intersections with the object in each line X++, X+2 and Xn
Find x, Xn2. Data compression is performed by storing these as end point coordinates. The data format is as shown in FIG. The leading l indicates the coordinate number of the Yn line, Yn indicates the coordinate value of the Yn line, and Xn
m indicates the m-th X coordinate value of the Yn line, and the last E
O3 means END OF 5LICE, and indicates the value in the depth direction in the Z-back 18.

In this way, data compression can be performed by storing each line, the coordinates of the intersection (end point) of the line and the object, and the number of coordinates included therein in the format described above for each slice. In other words, compared to conventional methods that use voxel data to store data that is not actually used, the present invention requires only the data of the contours to be stored, so the storage capacity is extremely small. can do.

Next, the projection data creation process will be explained with reference to FIG. 4 as well.

The Z buffer 8 contains data Zl, Z regarding the distance @ (depth) from the viewing plane Zo from the viewpoint E shown in FIG.
2,..., etc. are stored, and when a specific position is specified by the distance specifying means 9, this distance data and the compressed data are used to create a three-dimensional line at each point in the three-dimensional distance image creating means 4. A three-dimensional distance image is created by drawing the . Thereafter, the data is sent to the next three-dimensional projection data creation means 5 for processing. The three-dimensional distance image creation means 4 creates a three-dimensional distance image by affine transforming only the compressed data, that is, the outline of the object, and linearly interpolating the pixels therebetween to draw a three-dimensional line.

This type of calculation process significantly reduces the number of calculations,
It is possible to increase the projection speed. Thereafter, shading is applied by the three-dimensional projection data creation means 5, and the data is sent to the CRT display via the display control means 6 for display.

Further, the image cutting process is performed as follows.

The cutting process is performed by specifying a cutting surface by specifying an arbitrary position (range) in the depth direction for the 7-buff 78 by the cutting processing means 10, and by processing a three-dimensional distance image as described above. It can be performed.

As described above, when creating a three-dimensional distance image, according to the method of comparing distance data in the Z buffer (referred to as Z value comparison), data at a position with a large distance in the depth direction from the viewing plane , and then write only the data at small positions (or erase the data at shallow positions and give priority to the data at deep positions). Direction (Front)
The conventional method of writing data to
t.

This method has the advantage that a three-dimensional image at an arbitrary position can be obtained immediately compared to the "Front" method.

[Effects of the Invention] According to the present invention described in detail above, since three-dimensional projection processing is performed after data compression, storage capacity can be significantly reduced. Furthermore, since projection is performed only by affine transformation of the outline and linear interpolation, the projection speed can be increased. Furthermore, cutting processing can be easily performed simply by specifying an arbitrary range.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a conceptual diagram for explaining data compression processing according to the present invention,
FIG. 3 is a diagram of its data format, FIG. 4 is an explanatory diagram of distance data, and FIGS. 5 to 7 are explanatory diagrams of maxillofacial surgery as an example of the prior art. 1... Original image data storage means, 2... Binarized image data storage means, 3... Data compression processing means, 4... Three-dimensional distance image creation means, 5... Three-dimensional projection data Creation means, 6... Display control means, 7... CRT display, 8... Z buffer, 9... Distance designation means, 10... Cutting processing means.

Claims (3)

[Claims] (1) In a three-dimensional image processing device that binarizes original image data and creates three-dimensional projection data based on this binarized data, the coordinates of the end points of the object in the binarized data are determined, and the coordinates of the object are a data compression means for compressing data by storing a 3D distance image; A three-dimensional image processing device comprising: three-dimensional projection data creation means for creating projection data. (2) Select and specify specific position data of the distance data,
The three-dimensional image processing apparatus according to claim 1, which creates only three-dimensional projection data before or after this specific position. (3) The three-dimensional image processing apparatus according to claim 1, wherein image cutting is performed by specifying data in an arbitrary range in the distance data with respect to the three-dimensional projection data.