JP4814447B2 - Fundus image editing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fundus image editing apparatus capable of accurately cutting out individual fundus images when creating a panoramic image from a plurality of acquired fundus images.
[0002]
[Prior art]
Conventionally, when creating a panoramic image from a plurality of fundus images, the mask portion of the image and the fundus image portion in which the fundus is reflected are separated by image processing using the difference in brightness, and only the fundus image portion is extracted. A method of obtaining a panoramic image by joining together is used.
[0003]
[Problems to be solved by the invention]
However, the periphery of the fundus image portion often becomes dark, and in such a case, it is difficult to accurately cut out the mask portion and the fundus image portion using the difference in brightness. Also, the mask part depends on the adjustment of the mechanical position on the fundus camera side, and furthermore, the size and shape differ depending on the type of fundus camera, so it was difficult to cut out the mask part with a fixed shape in advance. .
[0004]
In view of the circumstances described above, an object of the present invention is to provide a fundus image editing apparatus capable of accurately cutting out a fundus image from a fundus image.
[Means for Solving the Problems]
According to the first aspect of the present invention, a fundus camera incorporating a fundus photographing mask configured to surround the fundus image region in which an image of the eye to be examined is captured is provided so as to be connectable, and acquired by the fundus camera. In a fundus image editing apparatus (1) having image editing means (6, 9) for removing a peripheral mask (MK) portion from a fundus image (PC) and extracting a fundus image area (ARA),
In the fundus camera, a dummy mask in which a dummy fundus image region having a peripheral portion formed narrower than the fundus image region of the fundus photographing mask is set so as to be settable,
In the state where the dummy mask is set on the fundus camera, a dummy image acquisition unit is provided for acquiring a dummy fundus image by photographing a subject having uniform brightness,
Providing dummy mask cutout means for cutting out the dummy mask portion from the dummy fundus image obtained by the dummy image acquisition means;
The image editing means removes the cut-out dummy mask portion from the fundus image acquired by the fundus camera to obtain a fundus image region corresponding to the dummy fundus image region;
It is constructed in this way.
[0009]
【Effect of the invention】
According to the first aspect of the present invention, the image editing means removes the surrounding mask portion from the acquired fundus image based on the cutout information stored in advance in the cutout information storage means. Even if there is, the fundus image can be accurately cut out from the fundus image.
[0014]
Note that the numbers in parentheses are for the sake of convenience indicating the corresponding elements in the drawings, and therefore the present description is not limited to the descriptions on the drawings.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing an example of a fundus image editing apparatus to which the present invention is applied, FIG. 2 is a schematic diagram showing image processing when a fundus image is cut out, and FIG. 3 is a mask information table of the fundus image. It is a figure which shows an example.
[0016]
As illustrated in FIG. 1, the fundus image editing apparatus 1 includes a main control unit 2, and the main control unit 2 includes a fundus camera 3, a display 5, an image capturing unit 6, a mask via a bus line 4. An information storage unit 7, a panoramic image editing unit 9, a mask information analysis unit 10, a keyboard 11, and the like are connected. Note that the fundus camera 3 is configured to be connectable to the bus line 4, and a plurality of fundus cameras 3 are selectively connected to the bus line 4 via connectors or the like to edit a panoramic image. I can do it.
[0017]
The fundus camera 3 has a base 13, and a chin rest 15 is provided on the base 13 in a form that can support the face of the subject with respect to the camera body. A camera body 16 is provided on the base 13 so as to be movable over a predetermined range in a horizontal direction, that is, in a direction perpendicular to the paper surface in the drawing. An objective lens 17 is to be photographed by the subject on the camera body 16. It is provided in a form that can face the eye to be examined.
[0018]
Since the fundus image editing apparatus 1 has the above-described configuration, in order to create a panoramic image from a plurality of fundus images obtained from the same eye, which are acquired by the fundus camera 3, first, the fundus image 3 is obtained. A process of separating the mask portion and the fundus image portion of the image from the obtained fundus image is performed.
[0019]
That is, in the fundus image PC acquired by the fundus camera 3, as shown in FIG. 2A, the black mask MK (shown by a broken line in the figure) built in the fundus camera 3 is transferred to the eye image. The fundus image PC is configured to surround the fundus image area ARA to be loaded, and the fundus image PC captured by the fundus camera 3 is stored in the image capturing unit 6.
[0020]
Therefore, when the fundus image editing apparatus 1 is connected to the fundus camera 3 to edit a panoramic image, first, the fundus image area ARA of the fundus photographing mask set in the fundus camera 3 is set in the fundus camera 3. Instead, a black dummy mask DMK in which a dummy fundus image area ARA1 having a slightly narrower peripheral portion CP is set is set, and a blank sheet is photographed in that state. Then, a dummy fundus image PC1 (which is not exactly the “fundus image” because the fundus is not captured) is obtained as shown in FIG. 2A and stored in the image capturing unit 6. Is done.
[0021]
The main control unit 2 instructs the mask information analysis unit 10 to analyze the dummy fundus image PC1 stored in the image capturing unit 6 and analyze the information of the dummy mask DMK. In response to this, the mask information analysis unit 10 performs a process of cutting out the dummy mask DMK from the dummy fundus image PC1, and the dummy fundus image PC1 has the dummy mask DMK black and the dummy fundus surrounded by the dummy mask DMK. Since the image area ARA1 is displayed in white, the cut-out process of the dummy mask DMK can be easily performed by a known image processing method using a brightness difference.
[0022]
An example of the cutout process is shown in FIG. That is, among the pixels constituting the dummy fundus image PC1, all the pixels of the dummy fundus image PC1 are binarized with “1” being a bright pixel and “0” being a dark pixel. As described above, the dummy fundus image PC1 is configured such that the dummy mask DMK is black and the dummy fundus image area ARA1 surrounded by the dummy mask DMK is white. The dummy fundus image area ARA1 is all “1”. Note that the diagram shown in FIG. 2B is a diagram schematically written for easy understanding, and does not correspond to FIG. 2A accurately.
[0023]
Thus, when the dummy fundus image PC1 is binarized, the mask information analysis unit 10 performs a process of specifying the dummy fundus image area ARA1. That is, as shown in FIG. 3, for each scanning line (pixels arranged in the horizontal direction) when the dummy fundus image area ARA1 is displayed on the display 5, the start address SA is specified and masked. The information is stored in the information storage unit 7 as a mask information table TABL.
[0024]
For example, in the case of FIG. 2B, the position of the boundary BD of the dummy fundus image area ARA1 indicated by the broken line, that is, the position where the binarized pixel changes from “0” to “1” is set as the start address SA. The pixel number NB from the leftmost pixel in the figure is specified. For each scanning line, when the start address position of the dummy fundus image area ARA1 is specified by the number of pixels NB, the length LG of the dummy fundus image area ARA1 for each scanning line is specified by the number of pixels, and mask information Store at the corresponding position in the table TABL.
[0025]
Thus, when the start address SA and the length LG of the dummy fundus image area ARA1 are stored for all scanning lines of the dummy fundus image PC1, the mask information table TABL for the dummy fundus image PC1 is completed.
[0026]
The mask information table TABL is stored as shown in FIG. For example, for the 120th scanning line (pixel group arranged in the horizontal direction) from the top of the fundus image PC1, the pixel position at which the image moves from the dummy mask DMK portion to the dummy fundus image area ARA1, and accordingly, the dummy fundus image area The start position of ARA1 is from the 56th pixel from the left in FIG. Then, it is shown that the dummy fundus image area ARA1 exists from the pixel position to the right by the length of 750 pixels and becomes the dummy mask DMK portion again from the 751st pixel. That is, the 750th pixel position from the start address SA is the end position of the dummy fundus image area ARA1. The same applies to the other scanning lines. Therefore, by referring to the mask information table TABL, the dummy fundus image area ARA1 can be easily extracted by cutting out the dummy mask DMK portion from the dummy fundus image PC1.
[0027]
In this way, by storing the dummy fundus image area ARA1 with the start address SA and the length (number of pixels) LG of the dummy fundus image area ARA1 for each scanning line (pixel group arranged in the horizontal direction), The end position of the dummy fundus image area ARA1 for each scanning line is also clearly set with a small memory capacity.
[0028]
Thus, the mask information table TABL for the black dummy mask DMK in which the dummy fundus image area ARA1 in a range slightly narrower than the fundus image area ARA1 of the mask MKM set in the fundus camera 3 connected to the bus line 4 is set. The mask information storage unit 7 stores the mask of the fundus camera 3 from the dummy mask DMK to the normal mask MK, and starts acquiring the fundus image PC for obtaining a panoramic image.
[0029]
When a sufficient number of fundus images PC for obtaining a panoramic image are acquired from the same eye to be examined through the mask MK and captured and stored in the image capturing unit 6, the main control unit 2 displays the panoramic image editing unit 9. On the other hand, a command is given to cut out and remove the surrounding mask MK portion from the acquired fundus image PC, and to extract only the center fundus image area ARA.
[0030]
In response to this, the panorama image editing unit 9 reads out the mask information table TABL as cutout information regarding the dummy fundus image PC1 stored in the mask information storage unit 7, and the dummy fundus image stored in the mask information table TABL. Based on the information regarding the area ARA1, the mask MK portion is cut out and removed from each fundus image PC. As already described, the dummy fundus image area ARA1 is set slightly narrower than the fundus image area ARA acquired using the original mask MK, and therefore, the dummy mask DMK portion is removed from the fundus image PC. In the fundus image area ARA corresponding to the obtained dummy fundus image area ARA1, the mask MK portion is surely excluded.
[0031]
Thus, for each fundus image PC, when the fundus image area ARA is cut out, a plurality of fundus image areas ARA cut out are connected by a known method to obtain a panoramic image. Each fundus image PC is accurately Since the mask MK portion is cut out and removed, the obtained panoramic image is not only accurate, but also processing for obtaining the panoramic image can be easily performed.
[0032]
In the above-described embodiment, when acquiring the dummy fundus image PC1, a blank sheet is photographed with the dummy mask DMK set. However, the acquisition of the dummy fundus image PC1 is not limited to the blank sheet, and uniform brightness is obtained. You may comprise so that the to-be-photographed object may be image | photographed.
[0033]
Further, when acquiring the dummy fundus image PC1, the mask originally mounted on the fundus camera 3 is used as it is without using the dummy mask DMK, and a dummy within a slightly narrow range is obtained from the obtained fundus image area ARA. The fundus image area ARA1 may be electronically cut out to obtain the mask information table TABL.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an example of a fundus image editing apparatus to which the present invention is applied.
FIG. 2 is a schematic diagram illustrating image processing when a fundus image is cut out.
FIG. 3 is a diagram illustrating an example of a mask information table of a fundus image.
[Explanation of symbols]
3 ... Fundus image acquisition means (fundus camera)
6 …… Image editing means (image capture unit)
7 ... Cutout information storage means (mask information storage)
9 …… Image editing means (panoramic image editing section)
PC …… Fundus image PC1 …… Image MK obtained by photographing a subject having uniform brightness …… Mask SA …… Start position LG …… End position (length)
ARA ....... Fundus image area ARA1... Dummy fundus image area TABL.

Claims (1)

A fundus camera incorporating a fundus photographing mask configured to surround the fundus image area in which the image of the eye to be examined is captured is provided so as to be connectable, and the surrounding mask portion from the fundus image acquired by the fundus camera In the fundus image editing apparatus having image editing means for removing the fundus image region by removing
In the fundus camera, a dummy mask in which a dummy fundus image region having a peripheral portion formed narrower than the fundus image region of the fundus photographing mask is set so as to be settable,
In the state where the dummy mask is set on the fundus camera, a dummy image acquisition unit is provided for acquiring a dummy fundus image by photographing a subject having uniform brightness,
Providing dummy mask cutout means for cutting out the dummy mask portion from the dummy fundus image obtained by the dummy image acquisition means;
The image editing means removes the cut-out dummy mask portion from the fundus image acquired by the fundus camera to obtain a fundus image region corresponding to the dummy fundus image region;
A fundus image editing apparatus configured as described above.

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