JPS6084671A - Extracting device for image contour - Google Patents

Abstract

PURPOSE:To extract automatically each normal contour part in continuous frames wherein a subject changes with time by tracing automatically variation of the contour of continuous frames and making corrections. CONSTITUTION:When an image contour is extracted, contour data on the current frame from a current contour register 4 is fetched in a decision circuit 9 and distance data [F(l)] on the last frame from a distance data memory 8, on the other hand, is fetched in a distance data register 10. The index (l) of said F(l) from the distance data memory 8 is inputted to an index register 11. Then, a permissible distance parameter (IBIN), correction parameter (NEG), and correction parameter (NW) are set by a parameter setter 12. When F(l)<=IBIN, a correct contour correcting device 5 stores the contour point of the current contour register 4 in a current contour memory 13 as an extracted contour. When F(l)> IBIN, necessary corrections are made with the correction parameters NEG and NW.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image contour extraction device that automatically extracts each contour of a plurality of consecutive frames in which a subject changes over time.

[Technical background of the invention and its problems]

For example, in the diagnosis of heart disease, left ventricular volume calculation, cardiac function evaluation, etc. are performed using X-ray contrast images.

Conventionally, the volume of the left ventricle has been calculated by a method in which a doctor or the like manually traces the contour of the left ventricle using a contrast-enhanced image, and calculates the volume based on this traced image. However, with this method, it takes time to obtain the calculated values, and 30 to 60 images (frames) are captured per second to correspond to the movement of the heart. Because the number of images is huge and the tracing process requires a lot of effort, in reality, it is either necessary to trace only the minimum necessary images out of the continuous images, or the process itself is abandoned. was.

In response to the above-mentioned circumstances, devices have been developed that manually extract the outline of an image, but an image outline extraction device that automatically extracts the outline of a target region has not yet appeared.

In addition, we are developing a device that can collect images of objects whose movements change over time, such as the heart, as multiple consecutive frames and automatically extract the outline of the target area from each frame to provide good diagnostic information. His appearance was strongly desired.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to extract image contours that can automatically extract each contour of a plurality of consecutive frames in which a subject changes over time. The goal is to provide equipment.

[Summary of the invention]

The image contour extracting device 6° according to the present invention includes a first storage means for storing the current frame to be displayed as an image, a current contour data calculation means for calculating the entire current contour data of the current frame;
A second storage device stores the previous contour data of the previous frame whose contour has already been extracted, and a second storage device stores the change in the contour between the previous frame and the fifth frame, and stores the previous contour data, the current contour data, and the extracted correction information. a current contour modifying means for modifying using a programmator; an image editing means for image editing the modified contour data from the current contour modifying means and the current frame from the first storage means; and a display means for displaying the W frames as images, and is characterized in that changes in the contours of successive frames are automatically tracked and corrected.

[Actual MI example of invention]

The image contour extraction apparatus according to the present invention will be described below with reference to an example shown in FIG.

In this embodiment, for example, the time to
X-ray fluoroscopic image frame Fo at time 1° frame F
Mftf for extracting contours of continuous frames for Fn at l, .+Ln will be described.

In FIG. 1, reference numeral 1 denotes an image collecting device that collects the above-mentioned frames. 2 is an A/D converter that converts the collected frames into digital information. 3 divides the r-notalized frame into, for example, k x k pixel data, and sequentially divides the frame by using, for example, spatial differential method or threshold method, based on the la degree information of each divided data. This is a contour extraction processing device that extracts a target contour portion for each pixel data. 4i1. The current contour register temporarily holds the frame contour data A (X, Y) obtained by the contour extraction processing device 3. ! After holding, the current contour correction device shown in 5 shows a long life.

6 is a pre-contour register that temporarily holds already obtained contour data, and as shown in FIG. The above contour data is given from the contour extraction process 1-(tii 3 for frame FoK at time 1o, and tx
In JJ descent, power is obtained from plain memory, which will be described later.

7t; 1, in the contour register 6 before adding 7 to Figure 2, an arbitrary array P'(A) = (xt, yt) and the contour P (
4=(xt.

This is a distance *+j calculation device that calculates the short distance F (t) between the distance F (t) and the distance F (t). 8 is a distance data memory that stores the distance 1 data F (4) and its index t.

Next, details of the current contour correction device 5 will be explained. That is, the current frame contour data A(
X, Y) are taken into the Fi determination circuit 9. On the other hand, the distance data F(a) of the previous frame from the distance data memory 8 is taken into the distance data register 10. Ru. Further, the distance data F of the previous frame from the distance data memory 8 (the index t of 4 is the index register 1) is taken in. 1
2 is the allowable distance parameter IBIN, correction parameter NE
C. Parameter setting device for setting correction parameter settings.

In the current contour correction device 5, when F (t)≦IBIN is satisfied, the contour point A(X, Y) of the current contour register 4 is
The extracted contour is stored in the current contour memory 13.

In the case of F(/=))IBIN, the correction value + parameter N
EG, NVI/contour correction is performed, for example, as shown in FIGS. 4 to 6.

The modified noise parameter NEG is, for example, the number of points (index t is 1, .1-2°, etc., and the above-mentioned -1, - 2).

The correction parameter table is, for example, the number of points beyond the shortest front contour point for the point exceeding the above-mentioned allowable distance IBIN (index t is '+1 '' +2 '..., and the above +1
．． +2i shown).

FIGS. 4 to 6 are diagrams for explaining the contour correction method described above in more detail. That is, in Fig. 4, point A
/ (x/, Y/) and previous coordinates are already stored in the current contour memory 14. Point A'(X'.

The distance F'(t) from the front contour at Y') is F'(t)) IBIN' with respect to the allowable distance IBIN', so the contour has been extracted for points NEG' up to point B'. When the direction is reversed, the heel, that is, the index t is 1-1.1-2.
・Line-line interpolation is performed from point B' to point C' with index tt, which is Nw' ahead of index t held in index register 1, and writes the coordinate string to the current contour memory 13 as a contour. . At this time, the contour points from point A' to point B' are removed from the current contour memory 13.

Points of the current contour corrected by the current contour correction device 5 are sequentially written into the current contour memory 13, and
4, the entire current contour is stored. Then, the current frame stored in the current frame memory 5 and the current contour in the lane memory 14 are data-synthesized using an image editing device to obtain image information of the current frame to be displayed, and this is
The /A converter 17 converts the image into analog and displays it on the display device 8.

With the above configuration, the outline of the previous frame that has already been extracted, the outline of the current frame to be displayed next, and the Q
:Il, the excessive change is corrected, and the contour of the target list that changes sequentially is automatically tracked and displayed as an image, and the contour images of consecutive frames are displayed without straying clearly. becomes possible.

The present invention is not limited to the above embodiments.

For example, in the current contour correction device 5, instead of connecting the corrected points on the previous contour, the point having the maximum probability value near point C' in FIG. 6 is extracted, and the point Linear interpolation may be performed from B'. As for interpolation, in addition to linear interpolation, curve approximation using an appropriate curve, Hugelin interpolation, or replacement with the previous contour itself may be used.

Also, when extracting contours, the allowable distance is used, but if the direction is significantly different from the direction that has been extracted so far, for example, if the contour can be considered rotated, The contour correction device 5Vc can perform multi-contour correction.

In addition, various modifications may be made without departing from the scope of the present invention.

〔Effect of the invention〕

As described above, the image contour extraction device according to the present invention includes a first storage means for storing the current frame to be displayed as an image;
a current contour data calculation means for calculating the current contour data of the current frame; a second storage means for storing the previous contour data of the previous frame whose contour has already been extracted; a contour correction means for correcting the change using the previous contour data, the current contour data and a predetermined correction parameter; Present from means) 1
7F consists of a picture [:] for editing the image, an editing means, and a display means for decompressing and displaying the current frame by %-ji+1 from this image editing means, so that changes in the contours of consecutive frames can be automatically performed. It is now possible to track and correct all of this, and it is possible to fully automatically extract each contour of the correct and negative images in 7 consecutive frames in which the subject changes over time.
EJ function is to display images.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the image contour extracting device according to the present invention, FIG. 2 is a block diagram showing the contents held in the previous contour register shown in FIG. Figure 1 is a diagram for explaining the storage contents of the short path data memory, and Figures 4 to 6 υ each illustrate the above-mentioned contour correction device.
This is a diagram for 1... - Image several year device, 2... Al1) Transformer, 3.
...Contour extraction processing equipment-14...Current contour register, 5
... Current contour correction device, 6... Front contour register,
7... Distance translation device, 8... Distance data memory, 1
3...Current contour memory, 14...Plane memory, 1
5... Current frame memory, 16... Image editing device,
17...D/A transformer, 18...Display bag tube.

Claims (1)

[Claims] a first storage means for storing a frame to be displayed as an image; a current contour data calculation means for calculating current contour data of the current frame; and a second storage means for storing previous contour data of a previous frame whose contour has already been extracted. means, current contour correction means for correcting a change in contour between the previous frame and the current frame using the previous contour data, the current contour data, and a predetermined correction parameter; and a correction from the current contour correction means. Image editing the current contour r-event and the current frame from the first storage means ii! An image contour extraction device comprising II image editing means and display means for displaying the current frame from the image editing means as an image.