JPH05154109A - Image processor for ophthalmology - Google Patents

Abstract

PURPOSE:To provide the image processor for ophthalmology which identifies the same parts of two images even without recognizing the shape of a mask and can connect the same parts in superposition without hindrance. CONSTITUTION:This image processor for ophthalmology is constituted to connect the two images by identifying the same image parts of the two images and superposing these two same image parts on each other and displays the images on a display means 1. The processor has comparing means 36, 37 which compare the brightness information of each of the respective picture elements of the two images with respective reference levels and a control means 39 for executing control in such a manner that the display by the brightness information of certain picture element is deleted and the display based on the brightness information of the picture element corresponding to the certain picture element of another image is made on the display means 1 when the brightness information of the certain picture element is lower than the reference level in accordance with the results of the comparison made by the comparing means 36, 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic apparatus for identifying (connecting) identical image parts of two images and superimposing the two identical image parts so that the two images are connected and displayed on a display means. The present invention relates to improvement of an image processing device.

[0002]

2. Description of the Related Art Conventionally, in the field of ophthalmology, each part of the fundus of the eye is imaged using a fundus camera, each fundus image is recorded in each frame memory, and the image data recorded in each frame memory is recorded. Image processing is performed using a computer as an image processing apparatus for ophthalmology and displayed on a monitor 1 as a display unit.

FIG. 1 shows an image 5 as a fundus image including a papilla portion 2 and a trunk portion 4 of a blood vessel 3, and FIG.
7 shows an image 7 as a fundus image including the branch portion 6 of FIG.
Mask images 8 and 9 corresponding to photographing masks provided in the photographing optical system of the fundus camera are formed on the images 5 and 7, respectively. The mask images 8 and 9 are indicated by diagonal lines. The mask images 8 and 9 are displayed in black on the screen.

[0004]

By the way, in the field of ophthalmology, recently, as shown in FIG. 3, the same portion 10 of each of the images 5 and 7 is identified, and the same portion is overlapped and connected. A fundus image formed by overlapping and connecting the images is displayed as a panoramic image 11.

However, the same portion 1 of each image is
If 0s are overlapped and connected, the portions 12 and 13 of the mask image indicated by the dashed diagonal lines overlap the useful portion of the other image, so that the appropriate panoramic image 1 is obtained.
There is an inconvenience that it is difficult to obtain 1.

Therefore, an ophthalmic image processing apparatus has been proposed in which the shape of a mask image is recognized, the mask image is removed, and then the same portions of the two images 5 and 7 are overlapped and connected. However, in the proposed ophthalmic image processing apparatus, the recognition means for recognizing the mask has to be changed according to the shape of the mask, so that there remains a problem of lacking versatility.

The present invention has been made in view of the above circumstances, and an object thereof is to identify the same portion of two images without any trouble even if the shape of the mask is not recognized. It is an object of the present invention to provide an ophthalmic image processing device capable of overlapping and connecting.

[0008]

In order to solve the above-mentioned problems, an ophthalmic image processing apparatus according to claim 1 of the present invention provides:
In an ophthalmic image processing apparatus for identifying the same image portion of two images and superimposing the two same image portions to connect the two images and display them on the display means, the luminance of each pixel of the two images Comparing means for comparing information with each reference level, and when the luminance information of a certain pixel is lower than the reference level based on the comparison result of the comparing means, the display by the luminance information of the certain pixel is deleted and the other image Control means for controlling the display means so that only the display based on the luminance information of the pixel corresponding to the certain pixel is performed.

[0009]

According to the ophthalmic image processing apparatus of the first aspect of the present invention, the same image portions of two images are identified and the same image portions are connected by superimposing the two same image portions. Then, the comparing means then compares the luminance information for each pixel of the two images with each reference level. The control means deletes only the display by the luminance information of a certain pixel when the luminance information of the certain pixel is lower than the reference level based on the comparison result of the comparing means, and deletes the pixel corresponding to the certain pixel of the other image. The display based on the luminance information is controlled to be displayed on the display means. As a result, it is possible to prevent the useless portion of the other image from being displayed overlapping the useful portion of the other image.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an ophthalmic image processing apparatus according to the present invention will be described with reference to the drawings.

In FIG. 4, 20 and 21 are frame memories, 22 is a changeover switch, 23 is a reading circuit, and 2
4, 25 and 26 are changeover switches, and 27 and 28 are internal memories. The frame memory 20 stores image data corresponding to the fundus image 5 shown in FIG. 1, for example.
The frame memory 21 stores image data corresponding to the fundus image 7 shown in FIG. 2, for example. The image data stored in the frame memories 20 and 21 are stored in internal frame memories 27 and 28 of the computer. When the image data of the frame memory 20 is read and stored in the internal memory 27, the frame memory 20 and the read circuit 23 are connected via the changeover switch 22, and the read circuit 23 and the internal memory 27 are changed over via the changeover switches 24 and 25. Connected. When the image data of the frame memory 21 is read and stored in the internal memory 28, the frame memory 21 and the read circuit 23 are connected via the changeover switch 22, and the read circuit 23 and the internal memory 28 are changed over by the changeover switches 24, 2.
Connected via 6.

The respective image data stored in the internal frame memories 27 and 28 are input to the reduction circuit 30 via the changeover switch 29 based on the reduction instruction. When reducing the image data stored in the internal memory 27, the internal frame memory 27 and the reduction circuit 30 are connected via the changeover switch 29, and the internal frame memory 2
When reducing the image data stored in 8, the internal frame memory 28 and the reduction circuit 30 are connected via the changeover switch 29.

The image data recorded in the internal frame memory 27 is reduced by the reduction circuit 30 and again recorded in the internal frame memory 27 via the changeover switch 25. The image data recorded in the internal frame memory 28 is reduced by the reduction circuit 30 and is again recorded in the internal frame memory 28 via the changeover switch 26. In this embodiment, the reduction circuit 30 reduces the panoramic image 11 as a superposed image formed by connecting the same portions 10 of the two images 5 and 7 in a superposed manner. This is because the monitor 1 having the same screen size is used for display.

The respective image data stored in the internal frame memories 27 and 28 are input to the superposition circuit 32 via the changeover switch 31 based on the superposition command. The overlay circuit 32 includes an internal frame memory 2
After the image data of 7 is input, the internal frame memory 2
9 image data is input. The superposition circuit 32
Input of image data into the is performed based on the superposition command.

The superposition circuit 32 identifies the same portion 10 of the images 5 and 7 and superimposes the same portion 10 to connect the images 5 and 7, and the panoramic image formed by the superposition. Output data to monitor 1. A panoramic image 11 shown in FIG. 3 is displayed on the monitor 1 by connecting the image 5 and the image 7. FIG. 5 is an enlarged view when two images are superimposed on each other in the panoramic image 11, and a useless mask image portion 12 shown by a broken line of the image 7 is displayed so as to be superimposed on a useful portion of the image 5. Further, a useless mask image portion 13 indicated by a dashed diagonal line of the image 5 is displayed so as to be superimposed on a useful portion of the image 7.

The overlapping portion of the two images on the screen of the monitor 1 and the image data of each pixel of the internal frame memories 27 and 28 (addresses of the internal frame memories 27 and 28) are connected via the connection switches 34 and 35. , Luminance comparison circuits 36 and 37. The brightness comparison circuit 36 compares the brightness data as image data called from a certain pixel of the internal frame memory 27 with the reference level L. Three
Reference numeral 8 is a reference level setting circuit for setting the reference level L. The brightness comparison circuit 37 compares the brightness data as image data called from a pixel in the internal frame memory 28 with the reference level L.

For example, if the range of the arrow A and the range of the arrow B are overlapped, focusing on the scanning line C having the range, a brightness curve based on the brightness information for each pixel is obtained as shown in FIG. ..

FIG. 6A shows the brightness curve X based on the brightness information for each pixel of the scanning line C of the image 5, and FIG.
Shows a brightness curve Y based on the brightness information for each pixel of the scan line C of the image 7. In FIG. 6A, the range indicated by the arrow D corresponds to the mask image portion D ′ of the image 7.

Now, focusing on the pixel K on the scanning line, the pixel K of the image 5 is the brightness information P of the image portion between blood vessels.
Have. On the other hand, the pixel K of the image 7 has the brightness information P ′ of the mask image portion. The brightness information P and the brightness information P ′ are simultaneously input to the brightness comparison circuits 36 and 37. The brightness comparison circuits 36 and 37 compare the brightness information P and P ′ with the reference level L. This is repeated for each pixel for each scanning line, and the series of comparison results is input to the determination circuit 39. The determination circuit 39 temporarily stores the information of each pixel based on the comparison result and performs the following control based on the storage.

When the luminance information of the pixel of the image 5 is smaller than the reference level L and the luminance information of the pixel of the image 7 corresponding to the pixel of the image 5 is smaller than the reference level L, the judging circuit 39 determines the pixel of the image 5 When the luminance information of the pixel of the image 7 is larger than the reference level L and the luminance information of the pixel of the image 7 corresponding to the image 5 is smaller than the reference level L, the luminance information of the pixel of the image 5 is larger than the reference level L. When the luminance information of the pixel corresponding to the image 5 is larger than the reference level L, the superimposing circuit 32 is controlled so that the luminance information of the pixel corresponding to the pixel of the image 5 of the image 7 is deleted. When the luminance information of the pixel is smaller than the reference level L and the luminance information of the pixel corresponding to the pixel of the image 5 of the image 7 is larger than the reference level L, the luminance information of the pixel corresponding to the image 7 of the image 5 Circuit superimposed as deleted 3
It has a function as a control means for controlling 2. Then,
The panoramic image 40 shown in FIG. 7 is displayed on the monitor 1. Each data of this panoramic image is stored in the frame memory 41.

Although the above processing is described as being performed by using hardware, this series of processing can be performed by using software.

Although the embodiment has been described above, in order to remove the noise component N of the brightness information X and Y shown in FIG. 8, the brightness information is averaged using a median filter, and the brightness information X, The level of Y is lowered, the levels of the luminance information X and Y are compared with a zero level as a reference level as shown in FIG. 10, each pixel of which the reference level is zero level is detected, and based on each pixel The mask image portion that overlaps the useful portion may be removed.

Further, the level of the brightness information X and Y is shown in FIG. 1 so that the minimum brightness is investigated and the level of the minimum brightness becomes zero.
As shown in FIG. 1, it may be lowered as a whole and then compared with the reference level L.

[0024]

Since the ophthalmic image processing apparatus according to the present invention is configured as described above, the same portions of the two embodiments can be identified and the same portions can be overlapped without any trouble without recognizing the mask shape. There is an effect that can be connected by.

[Brief description of drawings]

FIG. 1 is a diagram showing an image of a fundus portion of a fundus image.

FIG. 2 is a diagram showing an image of another fundus portion of the fundus image.

FIG. 3 is a diagram showing a fundus image formed by identifying the same portion of an image of one fundus region and an image of another fundus region and overlapping and connecting them.

FIG. 4 is a circuit diagram showing an example of an ophthalmic image processing apparatus according to the present invention.

5 is an enlarged view of the fundus image shown in FIG.

6 is a diagram showing an example of luminance information for explaining a process using the ophthalmic image processing device shown in FIG.

7 is a diagram showing a panoramic image processed by the ophthalmic image processing device shown in FIG. 4;

FIG. 8 is a diagram showing luminance information including a noise component.

FIG. 9 is a diagram showing luminance information from which noise components have been removed.

10 is a diagram in which the level of the luminance information shown in FIG. 9 is lowered.

FIG. 11 is a diagram in which the level of luminance information is lowered without removing noise components.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Monitor (display means) 32 ... Superposition circuit 36, 37 ... Comparator 39 ... Judgment circuit (control means)

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G09G 5/36 8121-5G // G06F 3/14 310 B 7165-5B

Claims (3)

[Claims] 1. An ophthalmic image processing apparatus which identifies two identical image portions of two images and superimposes the two identical image portions so that the two images are connected and displayed on a display means. Comparing means for comparing the luminance information of each pixel with each reference level, and deleting the display of the luminance information of a certain pixel when the luminance information of a certain pixel is lower than the reference level based on the comparison result of the comparing means. And a control means for controlling so that only the display based on the luminance information of the pixel corresponding to the certain pixel of the other image is displayed on the display means. 2. The ophthalmic image processing apparatus according to claim 1, further comprising a median filter for removing a noise component of each pixel of the two images. 3. The brightness level changing means for checking the minimum brightness of two images and changing the level of the minimum brightness so that the minimum brightness is zero is provided. The described ophthalmic image processing device.