JPH0363031A - Apparatus for ophthalmic measurement - Google Patents

Abstract

PURPOSE:To enable a hue of arterial reflection part on a fundus retina to be measured quantitatively by computing hue data from a normalized concentration data of every reference color image at remarked picture elements in a fundus image and by carrying out a hue display according to the obtained hue data. CONSTITUTION:A fundus retinal image is picked up in color with a CCD camera 2 fitted to a fundus camera 1, digitized by an A/D converter 3 and its R, G, B images are stored in an image memory 7. Next, the stored color image is displayed on a monitor 9, an area 16, which includes arterial reflection part of the fundus image, is specified and its enlarged image is displayed by a command input part 8. Several points in both non-reflection part 17 and reflection part 18 in that enlarged image are assigned and their representative values are defined by averaging several points in respective parts after omitting their maximum and minimum values. An address of the assigned image is stored in an address memory part 7, hue data are found out from respective concentration data of R, G and B images on the address by the image processor 5, and the non-reflection part and the reflection part of the arterial part are respectively plotted as H1 and H2 e.g. on a hue ring, so that the hue of the arterial reflection part on the fundus retina is measured quantitatively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ophthalmological measuring device for quantifying the hue of an arterial reflection area on the fundus retina.

[Prior art] Traditionally, the degree of enhancement of arterial reflexes seen in hypertension, retinal arteriosclerosis, etc. has been referred to by examiners as copper wire reflex, silver wire reflex, etc. Ta.

[Problem that the invention is trying to solve]

However, in the conventional example described above, since the examiner makes a subjective judgment, there are drawbacks such as the fact that even in the same case, different examiners make different judgments9 and that it is not possible to accurately recognize the degree of minute changes over time.

An object of the present invention is to provide an ophthalmological measuring device that eliminates the problems of the conventional example.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an ophthalmological measurement device that measures the hue of a fundus image using information on each reference color image that constitutes a fundus color image of an eye to be examined photographed with a predetermined imaging system. , a calculation means for calculating hue data based on the normalized density data of each reference color image at a notable pixel in the fundus image, and a hue for displaying the hue based on the hue data obtained by the calculation means. An angular display indicates that the device has a display means.

[Effect]

According to the present invention, for example, in a digital color fundus image, each density data of a Red image, a Green image, and a Blue image is converted into hue data, and the hue image is further plotted, for example, on a color wheel to determine the arteries on the fundus retina. Quantitatively measure the hue of the reflective area.

[Embodiment] Fig. 1 shows an embodiment of the present invention, in which 1 is a fundus camera, 2 is a CCD or camera, 3 is an A/D converter, and 4 is a fundus camera.
5 is a slide scanner, 5 is an image processing processor, 6 is an address storage section, 7 is an image memory, -8 is a command input section for sending commands to the image processing processor 5, and 9 is a monitor for displaying images, characters, graphs, etc.

FIG. 2 is a flowchart showing the flow of the embodiment shown in FIG.

Here, a specific implementation method will be explained with reference to FIGS. 1 and 2.

A CCD camera 2 attached to a fundus camera 1 captures a color fundus retinal image of the eye to be examined, and the obtained fundus image is digitized via an A/D converter 3 to produce a red image, a green image, Each Blue image is stored in the image memory 7 (FIG. 2-10).

The color image can also be input by inputting a 35-color slide using the slide scanner 4, or by inputting by A/D from an analog medium such as a still video or a video recorder (not shown).

Next, the color image stored in the image memory 7 is displayed on the monitor 9, and by inputting a command from the command input section 8, an area 1 including the arterial reflection part of the fundus image shown in FIG.
Identify 6. Then, an enlarged image of the area 16 was displayed as shown in Fig. 4, and several non-reflective areas 17 and several reflective areas 18 were designated on the enlarged image, and the maximum and minimum values were removed. Take the average at several points and use it as a representative value for each (Figure 2-11).

Although several points were set for each point here, the number is not limited to this, and any number of points greater than or equal to one point can be specified.

Then, the address of the designated image is stored in the address storage section 6 and is used. Next, the Red image, oreen image book, and Blue image on the address stored in the address storage unit 6 are
The image processing processor 5 obtains hue data from the image and each density data as described later, and the obtained hue data is placed on a hue circle as shown in FIG. , plot the part with reflection like H2 (Fig. 2-12, 13) and
The angle θ1 between H2 and H2 is calculated by the image processor 5 and displayed as an angle, so that the relative ratio between the reflective area and the non-reflective area can be quantitatively determined (FIG. 2-14).

Here, we will show a specific example of obtaining hue data from the density data of the Red image, Green image, and Blue image at the address. , the density data of each notable pixel of the Blue image is Ir.

If IP, Ib (o≦Ir, IP, Ib≦255), then M=max (IR, IG, IB), m=m1n (I
R, IG, IB)r=(M-IR)÷(M-m),
y=(M-IG)÷(M-m).

Calculate b = (M-I B) ÷ (M-m).

First, it is determined whether M=m.

) When M=m (IR=IG=IB), h=Q In other cases, judge whether IR2M or not ji) When IR2M, h=2+b−y Then, IG=M Determine whether it exists or not.

1ii) When IG:M, h=4+r-b and I
When R and IG are not M, i.e. iv) When IB=M, set h==5 +f −r, and 1) to iv) as H=hx6Q (mod 360) and hue data H.
seek.

Although the above embodiment has been described with respect to one digital fundus image, the present invention is not limited to this, and it is possible to perform processing on a plurality of digital fundus images in the same manner.

For example, an example of two images (two images of the same site that has changed over time, or images of different sites of the same subject's eye, etc.) is shown in FIG.

In the same figure, the part without reflection in the first fundus image is H3, the part with reflection is H5, the angle between H3 and H5 is θ2, and the part without reflection in the second fundus image is H.
4. The part with reflection is H6, the angle between H4 and H6 is θ
It is 3.

In this way, two images can be easily and accurately compared in terms of hue. The medium hue display is not limited to the hue ring display as shown in FIGS. 5 and 6, but may also be a horseshoe-shaped display as shown in FIG. 7, for example. Note that the hue display may be performed only by displaying the angle, or furthermore, the angular difference may be displayed as described above.

〔Effect of the invention〕

As described above, according to the present invention, the absolute value of the hue of the arterial reflective area on the fundus retina or the hue difference with the non-reflective area can be objectively displayed. For example, for two images of the same fundus taken at different times, it is possible to quantitatively recognize the hue difference between a reflective site and a non-reflective site, as well as changes over time in the degree of reflection.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a flowchart showing the flow of the embodiment in FIG. 1, FIG. 3 is a diagram showing a fundus image, and FIG. An enlarged view of the part, Figure 5 is a hue wheel plot diagram that can be clicked on one image, Figure 6
The figure is a hue ring plot diagram for two images, and FIG. 7 is a diagram showing different hues. In the figure, 1 is a fundus camera, 2 is a CCD camera, and 3 is an A/D
4 is a slide scanner, 5 is an image processing processor, 6 is an address storage section, 7 is an image memory, 8 is a command input section, and 9 is a monitor. Figure 3: Ten men

Claims (1)

[Scope of Claims] 1. In an ophthalmological measurement device that measures the hue of a fundus image using information on each reference color image that constitutes a fundus color image of an eye to be examined photographed with a predetermined imaging system, It has a calculation means for calculating hue data based on the normalized density data of each reference color image at a pixel of interest, and a hue display means for displaying the hue based on the hue data obtained by the calculation means. An ophthalmological measuring device featuring: 2. The ophthalmological measuring device according to claim 1, wherein the pixel of interest is a pixel within a retinal blood vessel. 3. The ophthalmologic measuring device according to claim 1, wherein said hue display means displays hue data on a hue wheel. 4. The ophthalmological measuring device according to claim 1, wherein the hue display means displays the hue data in terms of angle. 5. Claim 1, wherein there are a plurality of pixels to be noted, and the hue display means displays the difference between each hue data as an angular difference.
The ophthalmological measuring device described.