JP2009279026A - Ocular fundus imaging apparatus and ocular fundus image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique easily recognizing the state of which depth of a fundus is presented. <P>SOLUTION: The ocular fundus imaging apparatus 1 receives the fundus-reflected light of illumination light and generates the image data of the color image of the fundus Ef and the image data of three primary color components which are R components, G components and B components. Further, the ocular fundus imaging apparatus 1 analyzes at least one piece of the image data of the three primary color components, and displays the color image of the fundus Ef, the analyzed result of the image data of the primary color components and the indication of the kind of the primary color components corresponding to the analyzed image data. Kind information is the display color of an analyzed result specified beforehand for the respective primary color components. In the analysis of the image data of the primary color components, a lesion described in a primary color image is specified. As an analyzed result, a lesion image indicating the specified lesion is displayed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fundus photographing apparatus that captures a color image by photographing the fundus of a subject eye, and a fundus image processing apparatus that processes a color image of the fundus.

  In the ophthalmology field, various fundus photographing apparatuses for photographing the fundus in color have been conventionally used. As such an apparatus, a fundus camera, a slit lamp, a surgical microscope, and the like are known (see, for example, Patent Documents 1 to 6).

  A light source such as a halogen lamp or a xenon lamp is used for color photography of the fundus. The light source emits light including primary color components of R (red) component, G (green) component, and B (blue) component. These primary color components have intensity balance (color balance) according to the light source. In some cases, the color balance is adjusted by providing a filter between the light source and the eye to be examined. In general, the wavelength bands of these primary color components partially overlap. Further, the reflectances of these primary color components on the fundus are different from each other.

  Under the above conditions, in the fundus color photography, generally, the light amount (intensity) of the illumination light is set so that the density (brightness) of the G image is appropriate. In general, when an arbitrary amount of illumination light is used, the R image is brighter than the G image, and the G image is brighter than the B image.

  The fundus imaging apparatus disclosed in Patent Document 1 has a function of adjusting the color balance of the three primary color components in order to accurately represent the fundus color. In addition, the fundus imaging apparatus disclosed in Patent Documents 2 to 6 has a function of adjusting the amount of illumination light for imaging the eye to be examined in order to obtain an image that is easy for a doctor or the like to visually recognize.

  In recent years, a technique for analyzing an image acquired by a fundus photographing apparatus has been developed. For example, Patent Document 7 discloses a technique for detecting a optic papilla etc. by analyzing a primary color image constituting a color image.

  The R component, G component, and B component of the illumination light have different depths of arrival at the imaging region depending on the wavelength. For example, when photographing the fundus, the R component of the illumination light reaches the vicinity of the choroid and is reflected, so the R image is an image depicting a region extending from the retina to the vicinity of the choroid. In addition, since the G component of the illumination light reaches and is reflected near the pigment epithelium layer of the retina, the G image is an image depicting the vicinity of the pigment epithelium layer of the retina. Further, since the B component of the illumination light is reflected near the surface of the retina, the B image is an image depicting a shallow region of the retina.

JP-A-8-38430 JP-A-7-16206 Japanese Patent Laid-Open No. 7-231876 JP-A-8-52114 JP 2002-224036 A Japanese Patent Laid-Open No. 7-5369 JP 2005-253776 A

  Conventionally, in fundus image analysis, a G image having an appropriate density is often set as an analysis target. In particular, in the observation of a lesion, a G image is generally used, and a lesion site identified by analyzing the G image is displayed by being superimposed on a color image.

  In such conventional image analysis, a lesion site at a depth corresponding to the G image can be detected, but a lesion site not at this depth cannot be detected. That is, in the conventional image analysis, only the state of a specific depth of the fundus can be grasped. In addition, there is a demerit that it is impossible to grasp which depth state of the fundus is presented.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fundus photographing apparatus and a fundus image that can easily grasp which depth state of the fundus is presented. It is to provide a processing apparatus.

  Another object of the present invention is to provide a fundus photographing apparatus and a fundus image processing apparatus capable of observing the state of various depths of the fundus at a time.

  In order to achieve the above object, the invention according to claim 1 is directed to an illuminating means for irradiating illumination light to the fundus of the eye to be examined, and a reflected light of the illumination light by the fundus to receive a color image of the fundus Generating means for generating image data and image data of each of the three primary color components of R component, G component and B component; and analyzing means for analyzing at least one of the image data of the three primary color components; A primary color image based on the display means and the image data of the color image or the primary color component, an analysis result obtained by the analysis means, and type information indicating a type of the primary color component corresponding to the analyzed image data. And a control means for displaying on the display means.

  The invention according to claim 2 is the fundus photographing apparatus according to claim 1, wherein the type information is a display color of the analysis result designated in advance for each of the three primary color components. It is characterized by that.

  The invention according to claim 3 is the fundus photographing apparatus according to claim 1 or 2, wherein the analyzing means applies the primary color image to the primary color image based on the pixel value of the image data of the primary color component. The depicted lesion site is identified, and the control means displays, as the analysis result, a lesion site image representing a region corresponding to the identified lesion site, superimposed on the color image or the primary color image. It is characterized by.

  The invention according to claim 4 is the fundus imaging apparatus according to claim 3, wherein the analysis means analyzes two or more of the image data of the three primary color components, and the control means Is characterized in that, when the positions of a plurality of lesion site images based on image data of a plurality of primary color components overlap, a lesion site image having a small size is displayed superimposed on a lesion site image having a large size.

  The invention according to claim 5 is the fundus imaging apparatus according to any one of claims 1 to 4, wherein the illumination means sequentially irradiates the fundus with illumination light having different light amounts. The generating means receives the reflected light from the fundus of a large amount of illumination light to generate the image data of the B component, receives the reflected light from the fundus of the small amount of illumination light, and R component image data is generated.

  The invention according to claim 6 is the fundus imaging apparatus according to any one of claims 1 to 4, wherein the illuminating means emits three different amounts of illumination light to the fundus. The generation unit receives the reflected light from the fundus of a large amount of illumination light and generates image data of the B component, and receives the reflected light from the fundus of an intermediate amount of illumination light. Then, the G component image data is generated, and the R component image data is generated by receiving reflected light from the fundus of a small amount of illumination light.

  The invention according to claim 7 is the fundus photographing apparatus according to any one of claims 1 to 4, wherein the illumination unit is configured to reflect each of the three primary color components reflected by the fundus. Illuminating light having a color balance of R component, G component, and B component corresponding to is applied to the fundus of the eye to be examined.

  The invention according to claim 8 is the fundus imaging apparatus according to claim 7, wherein the illumination unit has the color balance such that the reflected light amounts of the three primary color components by the fundus are substantially equal. The illumination light is irradiated as described above.

  The invention according to claim 9 is the fundus imaging apparatus according to claim 8, wherein the illumination means includes a light source, the transmittance of the R component is equal to or less than the transmittance of the G component, and the G component A filter having a transmittance equal to or lower than the transmittance of the B component, and irradiating the fundus with the light output from the light source and transmitted through the filter as the illumination light.

  The invention according to claim 10 is a receiving means for receiving image data of a color image of the fundus of the eye to be examined and image data of each of the three primary color components of R component, G component and B component; Analyzing means for analyzing at least one of the image data of one primary color component, a display means and a primary color image based on the color image or the image data of the primary color component, an analysis result obtained by the analyzing means, A fundus image processing apparatus comprising: a control unit that causes the display unit to display type information indicating a type of a primary color component corresponding to the analyzed image data.

  According to the present invention, it is possible to display the type information indicating the type of the primary color component corresponding to the analyzed image data together with the color image or the primary color image and the analysis result. As described above, the image data of the three primary color components depict different depths of the fundus. Therefore, according to the present invention, it is possible to easily grasp which depth analysis result of the fundus is presented, that is, what depth state of the fundus is presented.

  In addition, according to the present invention, it is possible to collectively observe the state of the fundus at various depths by displaying two or more analysis results of the three primary color components together with the color image.

  An example of an embodiment of a fundus photographing apparatus and a fundus image processing apparatus according to the present invention will be described.

[Fundamental photography device]
A fundus camera will be described as a fundus photographing apparatus according to this embodiment. Note that the same configuration as in this embodiment can be applied to other fundus imaging apparatuses such as a slit lamp and a surgical microscope.

[Constitution]
The configuration of the fundus imaging apparatus according to this embodiment will be described. 1 to 3 show an example of the configuration of the fundus imaging apparatus according to this embodiment. The fundus imaging apparatus 1 has an appearance as shown in FIG. Note that the fundus imaging apparatus 1 may be configured to include only the fundus camera main body illustrated in FIG. 2, or may further include a computer connected to the fundus camera main body so as to be communicable.

  As shown in FIG. 2, a gantry 3 is provided on the base 2 of the fundus imaging apparatus 1. The gantry 3 can be moved three-dimensionally on the base 2. A control panel 3 a and a joystick 4 are installed on the gantry 3. The examiner operates the control panel 3a and the joystick 4 to cause the fundus imaging apparatus 1 to execute various operations and to input information.

  In particular, the operator can move the gantry 3 three-dimensionally on the base 2 by operating the joystick 4. An operation button 4a that is pressed when photographing the fundus is disposed on the top of the joystick 4.

  A support column 5 is erected on the base 2. The column 5 is provided with a chin rest 6a, a forehead pad 6b, and an external fixation lamp 7. The subject's jaw is placed on the jaw holder 6a. The forehead of the subject is brought into contact with the forehead pad 6b. The external fixation lamp 7 emits light for fixing the eye E to be examined.

  A main body 8 is mounted on the gantry 3. The main body 8 stores various optical systems and control systems of the fundus photographing apparatus 1. The control system may be provided in the base 2 or the gantry 3 or the like, or may be provided in a computer (described above) connected to the fundus camera body. The control system may be distributed in both the fundus photographing apparatus 1 and the computer.

  An objective lens portion 8a is provided on the eye E side of the main body portion 8 (the left direction in FIG. 2). The objective lens unit 8a is disposed at a position facing the eye E during examination. Further, an eyepiece 8b for the examiner to observe the fundus of the eye E to be examined with the naked eye is provided on the examiner side of the main body 8 (the right direction in FIG. 2).

  Further, the main body unit 8 is provided with two imaging devices 9 and 10 for taking a fundus image of the eye E. The imaging devices 9 and 10 are detachably attached to the main body unit 8.

  The imaging devices 9 and 10 are digital cameras equipped with imaging elements 9a and 10a, respectively. Each of the image pickup devices 9a and 10a includes a charge coupled device (CCD) image sensor, a complementary metal oxide semiconductor (CMOS) image sensor, and the like.

  The image sensors 9a and 10a receive light in different wavelength regions, for example. In this embodiment, the image sensor 9a receives light in the visible region, and the image sensor 10a receives light in the visible region and the infrared region.

  The image sensor 9a is used for color photography, and the image sensor 10a is used for monochrome photography. The imaging device 9 is provided with a control circuit that changes imaging conditions such as imaging sensitivity (ISO sensitivity) of the imaging element 9a and the number of imaging pixels. The image sensor 9a is, for example, a 3CCD type color image sensor. On the other hand, the imaging device 10 is provided with a control circuit that changes the imaging conditions such as the imaging sensitivity (gain) of the imaging element 10a and the number of imaging pixels.

  In this embodiment, a configuration in which two imaging devices are provided is adopted. However, the fundus imaging device according to the present invention is sufficient if it has at least one imaging device capable of color imaging. is there. The fundus photographing apparatus (fundus camera) may be either a mydriatic type or a non-mydriatic type.

[Configuration of optical system]
Next, the configuration of the optical system of the fundus imaging apparatus 1 will be described with reference to FIG. The optical system of the fundus photographing apparatus 1 includes an illumination optical system 100 and a photographing optical system 120.

  The illumination optical system 100 is an optical system for irradiating the fundus oculi Ef with illumination light. The illumination optical system 100 is an example of the “illumination means” in the present invention.

  The photographing optical system 120 is an optical system that guides fundus reflection light of illumination light to the eyepiece unit 8 b and the imaging devices 9 and 10. The photographic optical system 120 (particularly the imaging device 9) constitutes an example of the “generating means” of the present invention together with the primary color image generating unit 21 shown in FIG.

(Illumination optics)
The illumination optical system 100 includes an observation light source 101, a condenser lens 102, a photographing light source 103, a condenser lens 104, a filter unit 105, a ring translucent plate 107, a mirror 108, an LCD 109, an illumination diaphragm 110, a relay lens 111, a perforated mirror 112, An objective lens 113 is included.

  The observation light source 101 is a light source that outputs steady light (continuous light) for observing the fundus oculi Ef ′ with the naked eye or a captured image. The observation light source 101 is constituted by, for example, a halogen lamp. The condenser lens 102 condenses the steady light (observation illumination light) emitted from the observation light source 101 into a parallel light beam. As a result, the observation illumination light illuminates the fundus oculi Ef almost evenly.

  The photographing light source 103 is a light source that emits flash when photographing the fundus oculi Ef. The imaging light source 103 is constituted by a xenon lamp, for example. The condenser lens 104 condenses flash light (photographing illumination light) emitted from the photographing light source 103 into a parallel light flux. Thereby, the fundus oculi Ef is irradiated almost uniformly with photographing illumination light.

  The filter unit 105 is provided with an optical filter. As this optical filter, an exciter filter for FA (fluorescein fluorescence imaging; visible fluorescence imaging), an exciter filter for ICG (indocyanine green fluorescence imaging; infrared fluorescence imaging), an exciter filter for spontaneous fluorescence imaging, red There are filters for free photography.

  The filter unit 105 may be provided with a plurality of optical filters. In this case, for example, the filter unit 105 is driven by a drive mechanism (not shown), and these optical filters are selectively arranged on the optical path.

  The ring translucent plate 107 is a plate-like optical member having a ring translucent portion 107a composed of an annular translucent region. The ring light transmitting plate 107 is disposed at a position conjugate with the pupil of the eye E to be examined. The ring light transmitting plate 107 is disposed so that the center of the ring light transmitting portion 107 a is positioned on the optical axis of the illumination optical system 100. The mirror 108 reflects the illumination light emitted from the observation light source 101 and the photographing light source 103 in the optical axis direction of the photographing optical system 120. The LCD 109 displays a fixation target (internal fixation target: not shown) for fixing the eye E to be examined.

  The illumination stop 110 is a stop member that blocks a part of the illumination light. The illumination stop 110 is configured to be movable in the optical axis direction of the illumination optical system 100 and can adjust the illumination area of the fundus oculi Ef. The illumination stop 110 provides an effect such as preventing flare from occurring in the captured image.

  The aperture mirror 112 is an optical element that combines the optical axis of the illumination optical system 100 and the optical axis of the photographing optical system 120. A hole 112 a is opened in the center region of the perforated mirror 112. The optical axis of the illumination optical system 100 and the optical axis of the photographing optical system 120 intersect at the approximate center position of the hole 112a. The objective lens 113 is provided in the objective lens portion 8 a of the main body portion 8.

(Shooting optics)
The photographing optical system 120 will be described. The photographing optical system 120 includes an objective lens 113, a perforated mirror 112 (hole 112a), a photographing aperture 121, a filter unit 122, a focus lens 124, a variable power lens 125, an imaging lens 126, a quick return mirror 127, and an imaging device. 9 is comprised.

  The fundus reflection light of the illumination light is emitted from the eye E through the central dark portion of the ring-shaped image formed in the pupil of the eye E as described above. The fundus reflection light emitted from the eye E enters the imaging aperture 121 through the hole 112a of the aperture mirror 112. The perforated mirror 112 reflects the corneal reflected light of the illumination light. Thereby, generation | occurrence | production of the flare resulting from a cornea reflected light is prevented.

  The photographing aperture 121 is a plate-like member in which a plurality of circular translucent portions having different sizes are formed. The plurality of light-transmitting portions constitute apertures having different aperture values (F values). These translucent portions are alternatively arranged on the optical path by a driving mechanism (not shown).

  The filter unit 122 is provided with an optical filter. As this optical filter, there are a barrier filter for FA (fluorescein fluorescence imaging: visible fluorescence imaging), a barrier filter for ICG (indocyanine green fluorescence imaging: infrared fluorescence imaging), a barrier filter for spontaneous fluorescence imaging, and the like. is there.

  The filter unit 122 may be provided with a plurality of optical filters. In this case, for example, the filter unit 122 is driven by a driving mechanism (not shown), and these optical filters are selectively arranged on the optical path. The filter units 105 and 122 are controlled in cooperation so that the corresponding filters are arranged on the optical path.

  The focus lens 124 can be moved in the optical axis direction of the photographing optical system 120 by a focus lens driving unit (not shown). Thereby, the focus can be adjusted at the time of fundus observation or fundus photographing. The variable magnification lens 125 is inserted into and removed from the optical path by a driving mechanism (not shown) to change the angle of view (magnification). The imaging lens 126 acts to image the fundus reflection light from the eye E on the imaging element 9a of the imaging device 9.

  The imaging device 9 is used at the time of color photographing of the fundus as described above. The imaging device 9 receives fundus reflection light of photographing illumination light guided by the photographing optical system 120 and generates image data of each primary color component of R component, G component, and B component. The imaging device 9 includes, for example, a 3CCD type image sensor. That is, the three CCD elements respectively receive the R component, G component, and B component of the fundus reflection light of the photographic illumination light, and respectively receive R component image data, G component image data, and B component image data. Generate. The imaging device 9 combines the image data of these three primary color components to generate color image image data.

  The quick return mirror 127 is rotatably provided around the rotation shaft 127a by a driving mechanism (not shown). When photographing the fundus with the imaging device 9, the quick return mirror 127 obliquely provided on the optical path is flipped upward to guide the fundus reflected light to the imaging device 9. On the other hand, at the time of fundus photographing with the imaging device 10 or fundus observation with the naked eye, the fundus reflected light is reflected upward with the quick return mirror 127 obliquely arranged on the optical path.

  On the optical path of the fundus reflection light reflected by the quick return mirror 127, a field lens (field lens) 128, a switching mirror 129, an eyepiece lens 130, a relay lens 131, a reflection mirror 132, a photographing lens 133, and the imaging device 10 are provided. It has been.

  As with the quick return mirror 127, the switching mirror 129 is rotatable around the rotation shaft 129a. The switching mirror 129 reflects the fundus reflection light toward the eyepiece lens 130 while being obliquely provided on the optical path during fundus observation with the naked eye.

  Further, when a fundus image is captured using the imaging device 10, the switching mirror 129 is retracted from the optical path to guide the fundus reflection light toward the imaging element 10a. The fundus oculi reflection light is reflected by the reflection mirror 132 via the relay lens 131 and imaged on the image sensor 10 a by the photographing lens 133.

[Control system configuration]
The configuration of the control system of the fundus imaging apparatus 1 will be described with reference to FIG. The control system of the fundus imaging apparatus 1 includes a control unit 11, a storage unit 14, a user interface 15, a data processing unit 20, and the like.

(Control part)
The control unit 11 controls each unit of the fundus imaging apparatus 1. Specifically, the control unit 11 performs lighting / extinguishing control of the observation light source 101 and the imaging light source 103, operation control of the various driving mechanisms described above, and the like. In addition, the control unit 11 controls the operation of setting the exposure time (charge accumulation time), the shooting sensitivity, and the number of shooting pixels of each of the imaging devices 9 and 10. Further, the control unit 11 stores information in the storage unit 14 and reads information stored in the storage unit 14. Moreover, the control part 11 performs various arithmetic processing as needed.

(Light intensity control unit)
The light amount control unit 12 of the control unit 11 controls the light amount (photographing light amount) of photographing illumination light emitted from the photographing light source 103. The amount of photographing light can be controlled, for example, by adjusting the amount of charge accumulated in a capacitor that supplies current to the photographing light source 103.

(Display control unit)
The display control unit 13 of the control unit 11 controls the display mode of various information by the display unit 16. The control unit 11 (particularly the display control unit 13) is an example of the “control unit” of the present invention. In addition, the control unit 11 performs operation control of the fundus imaging apparatus 1 according to an operation on the operation unit 17 as control related to the user interface 15.

  The control unit 11 includes a microprocessor such as a CPU (Central Processing Unit). Further, the control unit 11 is provided with a storage device such as a ROM (Read Only Memory) or a hard disk drive that stores a computer program for causing the microprocessor to execute the above-described operation.

(Memory part)
The storage unit 14 stores various types of information used for operations and processing by the fundus imaging apparatus 1. For example, the storage unit 14 stores image data obtained by photographing the fundus oculi Ef. The storage unit 14 may store in advance table information in which display colors are associated with R, G, and B primary color components. The storage unit 14 includes a storage device such as a hard disk drive.

(User interface)
The user interface 15 is provided with a display unit 16 and an operation unit 17.

(Display section)
The display unit 16 is controlled by the display control unit 13 to display various screens and information. The display unit 16 is configured by an arbitrary display device such as an LCD (Liquid Crystal Display). The display unit 16 is provided, for example, on the main body unit 8 or the control panel 3a. The display unit 16 may be a computer display device connected to the fundus camera body. The display unit 16 functions as an example of the “display unit” of the present invention.

(Operation section)
The operation unit 17 is used by an operator to operate the fundus photographing apparatus 1. The operation unit 17 includes operation devices such as various buttons and keys. The operation unit 17 includes a control panel 3a, a joystick 4 and operation buttons 4a. The operation unit 17 may include an operation knob or the like for inserting / removing the filters provided in the filter units 105 and 122 on the optical path.

(Data processing part)
The data processing unit 20 performs various processes on the image data generated by the imaging devices 9 and 10 (particularly the imaging device 9). The data processing unit 20 includes a microprocessor such as a CPU, for example. The data processing unit 20 includes a primary color image generation unit 21 and an image analysis unit 22.

(Primary color image generator)
The primary color image generation unit 21 generates image data of each primary color component of the R component, the G component, and the B component based on the image data of the color image of the fundus oculi Ef generated by the imaging device 9. An image based on image data of each primary color component may be referred to as a primary color image. Hereinafter, an example of a method for generating image data of each primary color image will be described.

  The image data of a color image generally includes information for associating coordinate values (x, y) representing pixel positions in a frame with density values (r, g, b) of three primary color components (in addition, Various incidental information may be included).

  The primary color image generation unit 21 generates image data of each primary color image by collecting the information for each primary color component. Accordingly, R component image data r (x, y), G component image data g (x, y), and B component image data b (x, y) are obtained. The R component image data r (x, y) represents the density distribution of the r component in the frame. The same applies to the G component and the B component.

  The primary color image generation unit 21 does not have to generate all the image data of the three primary color images from the image data of one color image, and may generate only the image data of one or two primary color images. Good.

  Further, depending on the format of the image data generated by the imaging device 9, the primary color image generation unit 21 is not necessary. For example, when the imaging device 9 includes a 3CCD type image sensor and detection results of the R component, the G component, and the B component are input from the three CCD image sensors to the control unit 11, these three detection results. Can be used as image data of three primary color images as they are. In any case, it is sufficient that the fundus imaging apparatus 1 is configured to be able to generate image data of a color image of the fundus oculi Ef and image data of three primary color images.

(Image Analysis Department)
The image analysis unit 22 analyzes at least one of the image data of the three primary color images. The image data to be analyzed may be manually selected by the operator, or may be automatically selected by the image analysis unit 22 in accordance with the inspection contents. Alternatively, selection may be made at the stage where all three image data are always analyzed and the analysis result is displayed. The image analysis unit 22 is an example of the “analysis unit” in the present invention. Hereinafter, an example of analysis processing by the image analysis unit 22 will be described.

  The image analysis unit 22 specifies the lesion site of the fundus oculi Ef depicted in the primary color image based on the pixel value of the primary color image image data. This processing can be realized, for example, by performing threshold processing or boundary detection processing on pixel values included in the image data. As an example, by tracking changes in the pixel values of the pixels that make up the image data and identifying adjacent pixels where the change in the pixel values of adjacent pixels is greater than or equal to a predetermined value, the image area corresponding to the lesion site and the others The boundary with the image area can be detected. This process is effective for identifying a lesion site depicted as a difference in color or density, such as a white spot on the fundus oculi Ef. Note that a rough region of a lesion site can be manually designated in the display image of the primary color image (or color image), and the image analysis unit 22 may be configured to analyze only the designated region.

  As another analysis process, there is a process of specifying a characteristic part of the fundus oculi Ef depicted in the primary color image. Examples of the characteristic site include the optic nerve head, the macula, and the fundus blood vessel. The process of specifying the characteristic part of the fundus oculi Ef can be performed by a method similar to the conventional technique, for example. The analysis processing by the image analysis unit 22 may be processing for acquiring arbitrary information obtained directly from the image data of the primary color image, or processing for processing the arbitrary information and acquiring new information. May be. Examples of the latter include a process for obtaining the area of a feature part and a process for calculating a distance between two feature parts.

[Operation]
The operation of the fundus imaging apparatus 1 will be described. The flowchart shown in FIG. 4 represents an example of the operation of the fundus imaging apparatus 1.

  In this operation example, the fundus oculi Ef is imaged three times. These three shootings are performed while changing the shooting light quantity. At this time, considering the miosis of the eye E, the first shooting is a small amount of light (small light amount), the second shooting is an intermediate light amount (intermediate light amount), and the third shooting is It is desirable to carry out with a large amount of light (large amount of light). Note that the three shootings may be performed continuously, or may be performed at appropriate time intervals.

  Here, the intermediate light amount is a light amount for normal color fundus photographing. When shooting with an intermediate amount of light, a color image with an appropriate density and a primary color image with a G component are obtained. The small amount of light is set so that the density of the R component primary color image is appropriate. Similarly, the large light quantity is set so that the density of the primary color image of the B component is appropriate.

  These light quantities can be set based on, for example, clinical data obtained in advance, or can be set for each eye based on an observation image of the fundus obtained using observation illumination light. If the subject eye has been photographed in the past, the amount of photographing light at that time can be applied. In this case, the value of the photographing light amount applied at the time of fundus photographing is stored in the storage unit 14 or the like in association with the patient ID or the like. Further, when setting the light amount, the color balance of photographing illumination light, the reflectance of the fundus of the three primary color components, and the like may be taken into consideration.

  First, the fundus oculi Ef is photographed with a small amount of light (S1). Therefore, the light amount control unit 12 sets the photographing light amount by the photographing light source 103 to a small light amount. The control unit 11 controls the photographing light source 103 to emit a small amount of photographing illumination light. The imaging device 9 receives the fundus reflection light of the photographing illumination light, and generates image data of a color image of the fundus oculi Ef.

  The control unit 11 receives the image data of the color image and sends it to the data processing unit 20. The primary color image generation unit 21 generates R component image data based on the image data of the color image (S2). The R component image data is stored in the storage unit 14 by the control unit 11.

  Next, the fundus oculi Ef is photographed with an intermediate amount of light (S3). Therefore, the light amount control unit 12 sets the photographing light amount by the photographing light source 103 to an intermediate light amount. The control unit 11 controls the photographing light source 103 to emit photographing light with an intermediate amount of light. The imaging device 9 receives the fundus reflection light of the photographing illumination light, and generates image data of a color image of the fundus oculi Ef.

  The control unit 11 receives the image data of the color image and sends it to the data processing unit 20. The primary color image generation unit 21 generates G component image data based on the image data of the color image (S4). The G component image data is stored in the storage unit 14 by the control unit 11 together with the image data of the intermediate light quantity color image.

  Next, the fundus oculi Ef is photographed with a large amount of light (S5). Therefore, the light amount control unit 12 sets the photographing light amount by the photographing light source 103 to a large light amount. The control unit 11 controls the photographing light source 103 to emit a large amount of photographing illumination light. The imaging device 9 receives the fundus reflection light of the photographing illumination light, and generates image data of a color image of the fundus oculi Ef.

  The control unit 11 receives the image data of the color image and sends it to the data processing unit 20. The primary color image generation unit 21 generates B component image data based on the color image image data (S6). The B component image data is stored in the storage unit 14 by the control unit 11.

  The control unit 11 reads out the image data of the three primary color components R component, G component, and B component from the storage unit 14 and sends them to the data processing unit 20. The image analysis unit 22 analyzes the image data of each primary color component and specifies the lesion site depicted in each primary color image (S7). The result of specifying the lesion site is sent to the control unit 11.

  The control unit 11 reads out image data of a color image of the fundus oculi Ef from the storage unit 14. The display control unit 13 specifies a region in the color image corresponding to the lesion site of each specified primary color component (S8). At this time, the R component and B component image data and the color image image data are aligned as necessary. This process can be performed, for example, by matching the positions of characteristic parts (optic nerve head, macular part, blood vessels, etc.) in the image. Since the G component image data is generated from the color image image data, it is not necessary to perform alignment.

  Furthermore, the display control unit 13 sets the display color of an image (lesion site image) representing a region corresponding to the lesion site of each primary color component based on the table information (described above) stored in the storage unit 14 (S9). ). The display colors of these lesion site images are set, for example, such that the R component is red, the G component is green, and the B component is blue.

  When the above processing is completed, the display control unit 13 controls the display unit 16 to display the lesion site images of the three primary color components superimposed on the color image (S10). This display image may be, for example, a composite image in which a lesion site image is embedded in a color image, or an image in which a layer that presents a lesion site image of each primary color component is superimposed on a layer that presents a color image. There may be.

  An example of the image displayed in step 10 is shown in FIG. In this display mode, the lesion site images 40R, 40G, and 40B are displayed superimposed on the color image 30 of the fundus oculi Ef. Here, the lesion site image 40R represents an R component lesion site, the lesion site image 40G represents a G component lesion site, and the lesion site image 40B represents a B component lesion site.

  The lesion site image 40R is a red image representing a lesion site having a depth ranging from a deep region of the retina to the vicinity of the choroid. The lesion site image 40G is a green image representing a lesion site existing in a deep region of the retina. The lesion site image 40B is a blue image representing a lesion site existing in a shallow region of the retina.

  In the image area 41 of FIG. 5, lesion site images 40R, 40G, and 40B of three primary color components are displayed in an overlapping manner. This suggests the presence of lesions extending from the shallow area of the retina to the vicinity of the choroid. Such lesions generally have different sizes (cross-sectional areas) depending on the depth. The lesion present in the image area 41 has the largest size at the depth corresponding to the G component, and the smallest size at the depth corresponding to the R component.

  When presenting a lesion such as the image area 41, the display control unit 13 calculates the size of the lesion site image at the depth corresponding to each primary color component, and further converts the lesion site image having a smaller size into a lesion site image having a larger size. Overlay and display. In the image area 41, a lesion site image 40B is displayed on the lesion site image 40G, and a lesion site image 40R is displayed on the lesion site image 40B. By applying such a display mode, lesion site images at a plurality of depths of the fundus oculi Ef can be observed at a glance.

  In addition, when adopting a display mode such as setting the transparency of the lesion site image displayed on the upper side so that the lower lesion site image can be seen through, the order of overlaying the lesion site images is determined according to the size. do not have to.

[Action / Effect]
The operation and effect of the fundus imaging apparatus 1 will be described.

  The fundus photographing apparatus 1 receives fundus reflection light of illumination light and generates image data of a color image of the fundus oculi Ef and image data of three primary color components of R component, G component, and B component. Furthermore, the fundus imaging apparatus 1 analyzes at least one of the three primary color component image data, and corresponds to the color image of the fundus oculi Ef, the analysis result of the primary color component image data, and the analyzed image data. Type information indicating the type of the primary color component is displayed.

  According to such a fundus photographing apparatus 1, since the type information is displayed together with the color image and the analysis result, it is possible to easily grasp which depth analysis result of the fundus oculi Ef is presented.

  Further, by displaying two or more analysis results of the three primary color components together with the color image, it is possible to collectively observe various depth states of the fundus oculi Ef.

  The type information according to this embodiment is a display color of an analysis result designated in advance for each primary color component. In this embodiment, in the above-described table information, the display color of the R component analysis result is set to red, the display color of the G component analysis result is set to green, and the display color of the B component analysis result is set to blue. . Such a display color can be said to represent the depth of the fundus oculi Ef corresponding to the analyzed image data of the primary color component based on the relationship between the primary color component and the depth of the primary color image.

  The display color of the analysis result is not limited to the above setting, and can be arbitrarily set. In particular, when a display color other than the above setting is adopted, it is desirable to display information indicating which display color corresponds to which primary color component (the depth of the fundus oculi Ef). As an example, information that associates the display color with the color of the primary color component, information that associates the display color with the depth of the fundus oculi Ef, and the like can be displayed.

  In this embodiment, the image data of the primary color component is analyzed, and the lesion site depicted in the primary color image is specified. As a result of the analysis, a lesion site image representing a region corresponding to the identified lesion site is displayed superimposed on the color image of the fundus oculi Ef. Thereby, the depth, size, and position of the lesion of the fundus oculi Ef can be easily grasped.

  In this embodiment, the fundus oculi Ef is sequentially irradiated with photographing illumination lights having three different amounts of light, and B component image data is generated from the photographing result with the large light amount, and the G component is obtained from the photographing result with the intermediate light amount. Image data is generated, and R component image data is generated from the result of photographing with a small amount of light. Thereby, a primary color image having a suitable density can be acquired, and the accuracy and accuracy of the analysis process can be improved. In addition, a suitable primary color image can be displayed. In addition, since the color image of the fundus oculi Ef is acquired with the same intermediate light amount as in conventional color fundus imaging, a suitable color image similar to the conventional one can be acquired.

[Modification]
Various modifications according to the above embodiment will be described.

  In the above embodiment, the color image of the fundus is displayed together with the analysis result and type information, but a primary color image may be displayed instead of the color image. Here, a certain primary color image may be automatically selected and displayed, or the operator may select and display a desired primary color image. As an example of the former, it is possible to automatically select and display the primary color image of the primary color component with the most lesions. Note that the amount of lesion of each primary color component can be easily obtained by calculating the size of the lesion site image as described above. Examples of the latter include a configuration in which an operator selects an arbitrary primary color component, and a configuration in which a primary color image corresponding to a lesion site image selected and designated by the operator is selected and displayed.

  It is also possible to display any combination of the fundus color image and the three primary color images.

  The type information is not limited to the display color of the analysis result of the primary color component image data. As another example, the analysis results of the three primary color components can be displayed so as to be identifiable by gradation or a painting mode. It is also possible to present the depth of each analysis result by connecting the analysis result with a primary color component corresponding to the analyzed image data, that is, information indicating the depth of the fundus (character string information, etc.) and the analysis result. . As described above, the type information is not limited as long as it is information indicating the type of the primary color component corresponding to the analyzed image data, that is, the depth of the fundus corresponding to the analyzed image data.

  In the above embodiment, the photographing light quantity suitable for the three primary color components is set to perform the photographing three times. However, the image data of the three primary color components and the image data of the color image are obtained by the photographing twice. Is possible. Even in such a case, it is desirable to sequentially irradiate the fundus with illumination light having different light amounts, and to receive fundus reflection light of a large amount of illumination light to generate B component image data. On the other hand, R component image data is generated by receiving fundus reflection light of illumination light with a small amount of light. The G component image data may be generated from the reception result of the fundus reflection light of the illumination light with a large amount of light, or may be generated from the reception result of the fundus reflection light of the illumination light with a small amount of light.

  It is also possible to acquire image data of three primary color components and image data of a color image by one shooting. In that case, the fundus imaging apparatus irradiates the fundus with illumination light having a color balance corresponding to the reflectance of each of the three primary color components by the fundus. A fundus imaging apparatus according to this modification will be described. Details of matters described in this modification are described in Japanese Patent Application No. 2008-6796 by the present inventor.

  FIG. 6 illustrates a configuration example of an optical system of a fundus photographing apparatus according to this modification. This fundus photographing apparatus has an optical system substantially the same as the fundus photographing apparatus 1 of the above embodiment. However, a color correction filter 106 is added to the illumination optical system 100 of the fundus imaging apparatus. The photographing light source 103 is an example of the “light source” in the present invention.

  The color correction filter 106 generates photographing illumination light having a color balance corresponding to the reflectance of the fundus of the three primary color components. In other words, the photographic illumination light output from the photographic light source 103 is transmitted through the color correction filter 106 to have a spectral distribution converted into light having a color balance corresponding to the reflectance of each primary color component by the fundus. Here, the color balance represents the intensity ratio of the R component, the G component, and the B component.

  A specific example of the color correction filter 106 will be described. Generally, there are individual differences in the reflectance of the fundus of each primary color component of the R component, G component, and B component. For example, the reflectance varies depending on the race and also varies depending on the amount of melanin pigment. It is empirically known that the ratio of the reflectance is about R: G: B = 3: 2: 1 in Japanese people with a general amount of melanin pigment. For example, when a fundus color image is acquired using illumination light output from a normal xenon lamp, the density ratio of the three primary color images is approximately R: G: B = 3: 2: 1. It has been known. Moreover, it is known that the ratio of the reflectance is higher for a person with a small amount of melanin such as a white person than for a general Japanese (for example, R: G: B = 5: 3). : About 1).

  The color correction filter 106 is formed so as to generate photographing illumination light having a color balance in such a ratio that the amounts of light reflected by the fundus of the three primary color components are substantially equal. For example, when it is assumed that the ratio of reflectance by the fundus is R: G: B = 3: 2: 1, the light transmission characteristic is the inverse ratio of the reflectance ratio (that is, R: G: B = 1/3: A color correction filter 106 such that 1/2: 1 = 2: 3: 6) can be employed.

  Note that the “substantially” of the above “substantially equal” means that a predetermined deviation from the case of being completely equal is allowed. For example, a population of the reflected light quantity relating to an application target (for example, Japanese) of the color correction filter 106 can be regarded as “substantially equal” if it is included in the 90% confidence interval.

  Such an optical filter that changes the color balance of light is called a light balance filter or the like, and has been conventionally used in the field of photography. FIG. 7 shows an example of light transmission characteristics by the color correction filter 106. In this graph, the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance. Moreover, although this graph represents the transmission characteristic in the range of 400 nm-750 nm vicinity, it has a specific transmission characteristic also about wavelength ranges other than the said range.

  The transmission characteristics shown in this graph are set so that the R component transmittance is equal to or lower than the G component transmittance, and the G component transmittance is equal to or lower than the B component transmittance. This is because the color correction filter 106 having the transmission characteristics is used for fundus photography. That is, for the fundus, in general, (R component reflectivity) ≧ (G component reflectivity) ≧ (B component reflectivity), so that the amounts of light reflected by the fundus of the three primary color components are substantially equal. In order to generate photographing illumination light with a color balance of ratio, it is necessary to set the transmittances of the three primary color components as follows: (R component transmittance) ≦ (G component transmittance) ≦ ( B component transmittance).

  The color correction filter 106 is inserted into and removed from the optical path (illumination optical path) of the illumination optical system 100 by a drive mechanism (not shown). This drive mechanism includes an actuator such as a solenoid or a motor.

  Note that since there are individual differences in the reflectance of the fundus of the three primary color components, a plurality of color correction filters 106 can be selectively used in consideration of various reflectance types. is there. For example, a turret plate is provided with a plurality of color correction filters such as a general Japanese color correction filter, a color black color correction filter, and a white color human color correction filter. It is possible to arrange and use a desired color correction filter on the illumination optical path by rotating it with the same. The color correction filter can be selected manually by an operator, or automatically based on patient information, past examination information, and the like.

  According to such a modification, it is possible to acquire image data of suitable three primary color components by one shooting. It is also possible to use the color image obtained by this photographing as it is. As described above, there is an advantage that it is not necessary to perform the alignment process described in the above-described embodiment by acquiring all the image data in one shooting. In addition, effects such as omission of examination time and reduction of the burden on the subject can be expected.

[Fundus image processing device]
An embodiment of a fundus image processing apparatus according to the present invention will be described. A configuration example of the fundus image processing apparatus according to this embodiment is shown in FIG.

  The fundus image processing apparatus 200 is configured by a computer device used by a doctor, for example. The fundus image processing apparatus 200 includes a microprocessor, a RAM, a ROM, a hard disk drive, a display device, an operation device, a communication interface, a drive device, and the like, like a general computer apparatus.

  The fundus image processing apparatus 200 receives image data of a fundus color image acquired by the fundus imaging apparatus 300. Note that image data of the primary color image of the fundus may be input instead of the color image (in this case, the primary color image generation unit 261 is unnecessary).

  The fundus image processing apparatus 200 includes a control unit 210, a storage unit 220, a display unit 230, an operation unit 240, a data reception unit 250, and a data processing unit 260. The controller 210 is the same as the controller 11 of the above embodiment (the light amount controller 12 is not necessary). The storage unit 220 is the same as the storage unit 14. The display unit 230 is the same as the display unit 16. The operation unit 240 is the same as the operation unit 17. The data processing unit 260 is the same as the data processing unit 20. Further, the primary color image generation unit 261 and the image analysis unit 262 of the data processing unit 260 are the same as the primary color image generation unit 21 and the image analysis unit 22, respectively.

  Unlike the above embodiment, the fundus image processing apparatus 200 is provided with a data receiving unit 250 (receiving unit). The data receiving unit 250 receives image data of a color image (or a primary color image: the same applies hereinafter) acquired by the fundus photographing apparatus 300.

  When the fundus image processing apparatus 200 and the fundus imaging apparatus 300 are connected via a communication line such as a LAN, the data receiving unit 250 includes a communication interface such as a LAN card. The data reception unit 250 receives image data transmitted from the fundus imaging apparatus 300 (or via another apparatus) via a communication line and sends the image data to the control unit 210.

  When the data receiving unit 250 includes a drive device, the data receiving unit 250 can read the image data recorded on the recording medium and send it to the control unit 210.

  Note that the image data received by the data receiving unit 250 is image data obtained by performing, for example, one to three shootings as in the above embodiment. The fundus image processing apparatus 200 executes the same processing as in the above embodiment, for example, the processing of steps 2, 4, 6, 7 to 10 in the flowchart of FIG.

  According to the fundus image processing apparatus 200 as described above, the type information is displayed together with the color image (or primary color image) and the analysis result, so that it is possible to easily grasp which depth state of the fundus is presented. It is.

  Further, by displaying two or more analysis results of the three primary color components together with a color image (or a primary color image), it is possible to observe various states of the fundus at a time.

  Arbitrary configurations and operations disclosed in the description of the fundus imaging apparatus 1 of the above embodiment and the description of the modifications thereof can be applied to the fundus image processing apparatus 200.

It is a schematic block diagram showing an example of composition of an embodiment of a fundus photographing device concerning this invention. It is a schematic side view showing an example of the appearance composition of an embodiment of a fundus photographing device concerning this invention. 1 is a schematic side view illustrating an example of a configuration of an optical system according to an embodiment of a fundus imaging apparatus according to the present invention. It is a flowchart showing an example of operation | movement of embodiment of the fundus imaging apparatus concerning this invention. It is the schematic showing an example of the image of the fundus oculi displayed by the embodiment of the fundus imaging apparatus according to the present invention. It is a schematic side view showing an example of a structure of the optical system of the modification of embodiment of the fundus imaging apparatus concerning this invention. It is a graph showing an example of the characteristic of the color correction filter of the modification of embodiment of the fundus imaging apparatus concerning this invention. It is a schematic block diagram showing an example of composition of an embodiment of a fundus image processing device concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fundus imaging device 9, 10 Imaging device 11 Control part 12 Light quantity control part 13 Display control part 14 Storage part 15 User interface 16 Display part 17 Operation part 20 Data processing part 21 Primary color image generation part 22 Image analysis part 30 Color image of the fundus 40R, 40G, 40B Lesion site image 100 Illumination optical system 103 Imaging light source 106 Color correction filter 120 Imaging optical system E Eye to be examined Ef Fundus

Claims (10)

Illuminating means for illuminating the fundus of the eye to be examined; and
Generating means for receiving reflected light of the illumination light from the fundus and generating image data of a color image of the fundus and image data of each of three primary color components of R component, G component, and B component;
Analyzing means for analyzing at least one of the image data of the three primary color components;
A display unit, a primary color image based on image data of the color image or the primary color component, an analysis result obtained by the analysis unit, and type information indicating a type of primary color component corresponding to the analyzed image data. Control means for displaying on the display means;
A fundus photographing apparatus comprising: The type information is a display color of the analysis result designated in advance for each of the three primary color components.
The fundus imaging apparatus according to claim 1. The analysis means specifies a lesion site depicted in the primary color image based on a pixel value of the primary color component image data,
The control means displays, as the analysis result, a lesion site image representing an area corresponding to the identified lesion site, superimposed on the color image or the primary color image,
The fundus imaging apparatus according to claim 1, wherein the fundus imaging apparatus is provided. The analyzing unit analyzes two or more of the image data of the three primary color components;
The control means, when the position of a plurality of lesion site images based on the image data of a plurality of primary color components overlap, to display a lesion site image having a small size superimposed on a lesion site image having a large size,
The fundus imaging apparatus according to claim 3. The illumination means sequentially irradiates the fundus with illumination light having different light amounts,
The generation means receives reflected light from the fundus of a large amount of illumination light and generates image data of the B component, and receives reflected light from the fundus of a small amount of illumination light and receives the R component. Generate image data,
The fundus imaging apparatus according to any one of claims 1 to 4, wherein the fundus imaging apparatus is characterized. The illumination means sequentially irradiates the fundus with three different amounts of illumination light,
The generating means receives reflected light from the fundus of a large amount of illumination light and generates image data of the B component, and receives reflected light from the fundus of an intermediate amount of illumination light and receives the G component. Generating image data of the R component, receiving light reflected by the fundus of a small amount of illumination light and generating image data of the R component,
The fundus imaging apparatus according to any one of claims 1 to 4, wherein the fundus imaging apparatus is characterized. The illumination means irradiates the fundus of the subject's eye with illumination light having a color balance of R component, G component, and B component corresponding to the reflectance of each of the three primary color components by the fundus.
The fundus imaging apparatus according to any one of claims 1 to 4, wherein the fundus imaging apparatus is characterized. The illumination means irradiates the illumination light so as to have the color balance such that the reflected light amounts of the three primary color components from the fundus are substantially equal.
The fundus imaging apparatus according to claim 7. The illumination means includes a light source and a filter having an R component transmittance equal to or less than a G component transmittance and a G component transmittance equal to or less than a B component transmittance. Irradiating the fundus with the light that has passed through as the illumination light,
The fundus imaging apparatus according to claim 8. Receiving means for receiving image data of a color image of the fundus of the eye to be examined and image data of each of the three primary color components of R component, G component, and B component;
Analyzing means for analyzing at least one of the image data of the three primary color components;
A display means, a primary color image based on the image data of the color image or the primary color component, an analysis result obtained by the analysis means, and type information indicating a type of the primary color component corresponding to the analyzed image data. Control means for displaying on the display means;
A fundus image processing apparatus comprising: