JP6157521B2 - Ophthalmic imaging system - Google Patents

Description

  The present invention relates to an ophthalmic imaging system that is used in, for example, an ophthalmic clinic or the like and images a fundus portion such as a retina.

  Conventionally, in diagnosis using a color fundus image captured by a fundus camera, image processing such as gain, gamma characteristics, or color temperature is performed and the image is used for diagnosis so that an optimal color fundus image can be obtained.

  Patent Document 1 discloses that image processing is performed by automatically setting optimum processing parameters according to a plurality of shooting modes. In addition, in recent years, color fundus images, for example, not only use 8-bit color (R, G, B) color images for diagnosis, but also comprise color images. For example, it is becoming popular to make a diagnosis by separating each image into (8-bit R), (8-bit G), and (8-bit B) images, and processing and displaying the images.

  Patent Document 2 discloses that a captured raw image is subjected to image processing for each color component to faithfully reproduce a color image and an image for each color component.

JP 2001-245851 A JP 2001-352555 A

  In general, the following two methods are used when an image for each plane of R, G, and B is used for diagnosis together with a color fundus image.

  (1) A captured raw image, for example, 12 bits (R, G, B) is compressed and stored in a color image. A color image compressed and stored at the time of image interpretation, for example, 8-bit (R, G, B) is converted into an image for each plane (8-bit R), (8-bit G), (8-bit B) image. How to separate and display it.

  (2) Save all captured raw images, for example, 12 bits (R, G, B), perform image processing for each plane at the time of interpretation, and process each plane image (8 bits R), (8 bit · G), (8 bit · B) A method of displaying an image.

  In either case, each plane image based on the color balance of the color image that is the original image is individually adjusted and displayed.

  However, since the image for each color component displayed by the method (1) is an image obtained by performing image processing on the color image after compression, it is difficult to see the lesion site where the gradation is lost. Become. On the other hand, since the image of each plane displayed in (2) is an image obtained by performing image processing on the image of each plane of the raw image, the gradation is not lost, but it is necessary to record the raw image.

  With the recent increase in resolution of image pickup devices, the amount of data of the original image to be recorded has increased. Therefore, the method (2) that requires recording of a raw image has a large data capacity load on the apparatus and is easy to use. It ’s bad.

  The object of the present invention is to solve the above-mentioned problems and improve the interpretation accuracy without impairing the usability of the diagnostic apparatus in fundus diagnosis in which image display is performed for each of R, G, and B planes together with a color image. Is to provide a unique ophthalmic imaging system.

To achieve the above object, an ophthalmologic photographing system of the present invention includes an illumination unit that illuminates the fundus, a photographing optical system that receives light reflected from the fundus of illumination light by the illumination unit, and forms a fundus image, An image pickup means for picking up an image of the fundus image formed by the photographing optical system by separating it into three colors, an A / D conversion means for digitally converting the three-color separated image signal output from the image pickup means, and the A In the ophthalmologic photographing system, comprising: image data generation means for generating image data from raw image data converted by the / D conversion means; and output means for displaying or recording the image data generated by the image data generation means. The image data generation means includes a first image generation process for outputting first image data for color output, and a second image generation process for outputting second image data of an image for each of the R, G, and B planes. The first image generation process generates the first image data by performing gradation compression processing after performing image processing in which color balance is maintained on the raw image data, and The two-image generation process generates the second image data by performing gradation compression processing after performing image processing for expanding the dynamic range for each of the raw image data for each of the R, G, and B planes , output means, characterized in that it have a recording means for recording the second image data generated by said generated by the first image generation process first image data and the second image generation process.

According to the ophthalmologic imaging system of the present invention, it is possible to obtain an image with a wide dynamic range and rich gradation even when the data load is light and the obtained image is displayed independently of RGB.

  If a plurality of images can be displayed at the same time, it is easy to compare the images and the diagnostic efficiency is improved.

1 is a configuration diagram of an ophthalmologic imaging system according to Embodiment 1. FIG. It is a change figure of the generation histogram of the 1st fundus image from raw image data. It is a change figure of the histogram of generation of the 2nd fundus image from raw image data. It is a change figure of the histogram of R plane of generation of the 2nd fundus image from raw image data. It is a change figure of the histogram of G plane of the generation of the 2nd fundus image from raw image data. It is a change figure of the histogram of B plane of the 2nd fundus image generation from raw image data. It is explanatory drawing of the image of an image display part.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 is a configuration diagram of an ophthalmic imaging system according to a first embodiment. The ophthalmic imaging system includes a fundus camera 1, a digital camera 2 that can be attached to and detached from the fundus camera 1, and a personal computer 3 for image processing and image recording. Yes.

  The fundus camera 1 and the personal computer 3 are connected using a communication path 4. A photographing permission signal S1 is output from the fundus camera 1 through the communication path 4, and a photographing setting signal for gain, gamma, and color temperature for setting the photographing mode information and the light receiving sensor unit of the digital camera 2 is output from the personal computer 3. S2 is output. In addition, the digital camera 2 and the personal computer 3 communicate with each other using the communication path 5, and raw image data D <b> 1 photographed from the digital camera 2 is output to the personal computer 3.

  The fundus camera 1 is provided with an optical path O1 of the fundus illumination optical system from the observation light source 11 to the objective lens 12. In this optical path O1, a condenser lens 13, a photographing light source 14, a relay lens 15, a mirror 16, a diaphragm 17 having a ring-shaped opening, a relay lens 18, and a perforated mirror 19 are sequentially arranged.

  On the optical path O2 of the fundus photographing optical system in the transmission direction of the perforated mirror 19, a focusing lens 20, a photographing lens 21, and a movable mirror 22 are arranged. On the optical path O3 of the finder optical system in the reflection direction of the movable mirror 22, a mirror 23, a field lens 24, and an eyepiece lens 25 are arranged.

  Further, a fundus camera control unit 26 is provided inside the fundus camera 1, and the fundus camera control unit 26 is connected to the shooting start switch 27, the observation light source 11, the shooting light source 14, the digital camera 2, and the personal computer 3. ing.

  Inside the digital camera 2 is arranged on the extension of the optical path O1 of the fundus camera 1, and is an image pickup means 31 such as a CCD having three color separation means for R, G and B, and an image signal from the image pickup means 31 is digitally converted. An A / D conversion unit 32 and a digital camera control unit 33 are provided. The digital camera control unit 33 is connected to the fundus camera control unit 26 of the fundus camera 1.

  The personal computer 3 is provided with image generation process switching means 41. The two outputs of the image generation process switching means 41 are connected to the personal computer control unit 44 via a first image generation process 42 and a second image generation process 43 for generating image data, respectively. The personal computer control unit 44 is connected with an imaging mode selection unit 45, an imaging condition information input unit 46 for setting a patient name and other setting conditions, an image recording unit 47, and an image display unit 48 including a monitor. The raw image data D1 that is the output of the A / D conversion unit 32 of the digital camera 2 is connected to the image generation process switching means 41 via the communication path 5, and the personal computer control unit 44 is connected via the communication path 4. The fundus camera control unit 26 of the fundus camera 1 is connected.

  When the patient to be photographed is determined, the personal computer 3 uses the photographing condition information input unit 46 to select the patient and the patient information, the photographing mode selection unit 45 selects the photographing mode, and the color mode is selected in the first embodiment. Is done. At that time, a shooting setting signal S2 is output via the communication path 4 and set to the fundus camera 1 and the digital camera 2 via the fundus camera control unit 26. In this state, an alignment operation and a focus operation for the eye E are performed. When the imaging region is determined, the operator operates the imaging start switch 27 of the fundus camera 1 to perform fundus imaging.

  The fundus camera control unit 26 of the fundus camera 1 emits the imaging light source 14 in response to an input from the imaging start switch 27. The photographing light emitted from the photographing light source 14 illuminates the fundus Er of the eye E via the fundus illumination optical system, and the reflected light from the fundus Er forms an image on the image pickup means 31 of the digital camera 2 to be imaged. . The captured fundus image is converted into an electrical signal by the imaging means 31, and the A / D conversion unit 32 generates raw image data D1. The generated raw image data D1 is input to the image generation process switching means 41 of the personal computer 3 through the communication path 5.

  The first embodiment has two modes, a first image generation mode and a second image generation mode. The first image generation mode is a case where the image generation process switching means 41 that receives the input of the raw image data D1 outputs the output to the first image generation process. On the other hand, the second image generation mode is a case where the image generation process switching means 41 outputs the output to both the first and second image generation processes 42 and 43.

  When the raw image data D1 of the R, G, and B planes shown in FIG. 2A is input by the output switching by the image generation process switching unit 41, the first raw image data D1 is converted into the input raw image data D1. On the other hand, processing such as gain, gamma, and color temperature is performed. When a color fundus image is displayed, a color balance that is optimally displayed is maintained, and the first color output for gradation output is performed on the raw image data D1 as shown in FIG. 2B. Image data D2 is generated. In addition, when performing a compression process, you may also perform spatial frequency compression simultaneously.

  When the raw image data D1 is input to the second image generation process 43, the second image generation process 43 performs image processing on each of the R, G, and B planes of the input raw image data D1, and finally Specifically, the second image data D3 shown in FIG. 3 is generated.

  In this case, the R plane of the raw image data D1 is an image in which each luminance value before image processing is saturated, so that the dynamic range of the dynamic range as shown in FIG. Image processing is performed so that a wide image is obtained.

  The G and B planes of the raw image data D1 are images in which each luminance value before image processing is slightly insufficient and the gradation is slightly poor. Therefore, the image average luminance value is slightly increased by gain processing, and image processing is performed so that an image having a wide dynamic range is obtained by gamma processing, as shown in FIGS.

  When the color display, that is, the R, G, B plane is displayed, the raw image data D1 is an image in which the color balance is lost as shown in FIG. However, the second image data D3 shown in FIG. 3B, which is separated for each of the R, G, and B planes and subjected to the gradation compression processing, is an image in which the image for each plane is easy to see when displayed. It has become.

  The first and second image data D2 and D3 generated by the image generation process in this way are input to the personal computer control unit 44 and recorded or displayed on the image display unit 48 by the image recording unit 47.

  The second image data D3 generated according to the first embodiment is image data obtained by performing image processing on each plane of the raw image data D1 and then performing gradation compression. On the other hand, (1) in the column of “Problems to be solved by the invention” described above performs image processing on each plane of color image data subjected to gradation compression. Therefore, the first embodiment can obtain an image having a wide dynamic range and rich gradation as compared with (1).

  In addition, the first and second image data D2 and D3 recorded in the first embodiment are data after gradation compression. On the other hand, the data recorded in the above (2) is raw image data. Therefore, it can be said that the first embodiment has a lighter data capacity load and is easier to use than (2). In addition, even if the second image data D3 generated in the first embodiment is displayed for each plane, the displayed image is an image obtained by subjecting the raw image data to image processing and subsequent gradation compression processing. Therefore, an image sufficient for diagnosis can be obtained.

  In addition, since the first embodiment includes two image generation modes of the first and second image generation modes, for example, when an operator uses images of an R plane, a G plane, and a B plane in addition to a color image for diagnosis. The second image generation mode is selected. On the other hand, when only a color image is used for diagnosis, the first image generation mode can be selected. Since the former or the latter can be selected according to the operation application using the imaging condition information input unit 46 of the operator, it is easy to use.

  The personal computer control unit 44 may record the first image data D2 as one image data in the image recording unit 47 and may record the second image data D3 as one image data in the image recording unit 47.

  That is, the number of images to be recorded increases to two, but the image is an image after gradation compression, and the data recorded in the above (2) is raw image data. Therefore, compared with (2), the data capacity load of the device is light and convenient. In addition, even if the generated second image data D3 is displayed for each plane, the displayed image is an image that has been subjected to image processing on the raw image data and subjected to subsequent gradation compression processing. An image sufficient for diagnosis is obtained.

  Although the configuration of the second embodiment is the same as that of the first embodiment, the first image data D2 and the second image data D3 obtained in the second embodiment are displayed on the image display unit 48 at the same time.

  As described in the first embodiment, when the second image generation mode is selected, the first image data D2 and the second image data D3 are output from the first image generation process 42 and the second image generation process 43. In the second embodiment, the personal computer control unit 44 displays the first image data D2 and the second image data D3 on the image display unit 48 as shown in FIG. Here, (C) is the first image data D2, (R) is an image obtained by extracting only the R plane of the second image data D3, (G) is an image obtained by extracting only the G plane of the second image data D3, ( B) is an image obtained by extracting only the B plane of the second image data D3.

  In this way, by displaying four images on one screen, it is possible to view a color image, an R plane image, a G plane image, and a B plane image side by side, making it easy to compare the images and improving usability. For diagnostic use, diagnosis is performed by looking at the color image, R plane image, G plane image, and B plane image displayed on the image display unit 48.

  Note that the operator who sees the image displayed in FIG. 7 can record only the first image data D2 in the image recording unit 47 and can discard the second image data D3. As described above, the recording capacity load of the apparatus can be reduced when only a color image is sufficient for recording purposes, that is, when recording of an R plane image, a G plane image, and a B plane image is not necessary.

DESCRIPTION OF SYMBOLS 1 Fundus camera 2 Digital camera 3 Personal computer 4, 5 Communication path 26 Fundus camera control part 31 Imaging means 33 Digital camera control part 41 Image generation process switching means 42 1st image generation process 43 2nd image generation process 44 Personal computer control part 45 Shooting mode selection section 46 Shooting condition information input section 47 Image recording section 48 Image display section D1 Raw image data D2 First image data D3 Second image data S1 Shooting setting information S2 Shooting permission signal

Claims (3)

An illuminating unit that illuminates the fundus, a photographing optical system that receives light reflected from the fundus of the illumination light by the illuminating unit, and forms a fundus image, and a fundus image formed by the photographing optical system is separated into three colors Imaging means for imaging, A / D conversion means for digitally converting the three-color-separated image signal output from the imaging means, and image data from the raw image data converted by the A / D conversion means In an ophthalmologic photographing system having image data generating means to generate and output means for displaying or recording image data generated by the image data generating means,
The image data generation means includes a first image generation process for outputting first image data for color output and a second image generation process for outputting second image data of an image for each of the R, G, and B planes. Have
The first image generation process generates the first image data by performing gradation compression processing after performing image processing in which color balance is maintained for the raw image data,
Said second image generation process, R, G, with respect to the raw image data for each B planes, respectively to generate the second image data by performing the gradation compression processing after the image processing to widen the dynamic range ,
And the output means, ophthalmic, characterized in that have a recording means for recording the second image data generated by said generated by the first image generation process first image data and the second image generation process Shooting system.   The output means includes display means for displaying a photographed image, and a total of four types of images including an image of the first image data and an image separated for each of the R, G, and B planes of the second image data. 2. The ophthalmologic photographing system according to claim 1, wherein the images are displayed simultaneously on the display means.   2. The image processing in the first image generation process is luminance conversion processing that maintains a color balance, and the image processing in the second image generation process is luminance conversion processing for changing each average luminance. The ophthalmic imaging system described in 1.

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