Tooth row image generation device, tooth row image generation method, and program

Abstract

A tooth row image generation device comprises: an acquisition unit (51) that acquires a captured image obtained by imaging the surface of a tooth row and dental plaque within an oral cavity being irradiated with light including a wavelength region of blue light; a combination unit (53) that generates a tooth row image obtained by combining a plurality of tooth row block images, which are partial tooth row images based on the captured image; and a processing unit (52) that performs a white balancing process on the combined tooth row image.

Description

Dental row image generating device, dental row image generating method, and program

[0001] The present disclosure relates to a dentition image generating device, a dentition image generating method, and a program.

[0002] Patent Document 1 discloses a device that has an excitation light emitting unit that emits excitation light to cause plaque, lesions, etc. to emit fluorescence, and an illumination light emitting unit that emits illumination light to illuminate the periphery of plaque, lesions, etc., and that the irradiation means is capable of simultaneously irradiating the illumination light and the excitation light. Patent Document 1 also discloses that in order to improve the visibility of plaque, lesions, etc., the amount of light emitted from the excitation light emitting unit is greater than the amount of light emitted from the illumination light emitting unit.

[0003] WO 2005 / 104926

[0004] Incidentally, it is desirable for a row-of-teeth image generating device that generates a row-of-teeth image to generate a row-of-teeth image that gives a less uncomfortable feeling.

[0005] Therefore, the present disclosure provides a row-of-teeth image generating device, a row-of-teeth image generating method, and a program that are capable of generating a row-of-teeth image with reduced discomfort.

[0006] A dentition image generating device according to one aspect of the present disclosure includes an acquisition unit that acquires a captured image obtained by photographing the surface of the dentition and dental plaque in an oral cavity irradiated with light including a wavelength range of blue light, a synthesis unit that generates a dentition image by synthesizing multiple dentition block images, which are partial dentition images based on the captured image, and a processing unit that performs white balance processing on the synthesized dentition image.

[0007] A method for generating a dentition image according to one aspect of the present disclosure acquires an image obtained by photographing the surface of the dentition and dental plaque inside the oral cavity irradiated with light including the wavelength range of blue light, generates a dentition image by combining multiple dentition block images, which are partial dentition images based on the photographed image, and performs white balance processing on the combined dentition image.

[0008] A program according to one aspect of the present disclosure is a program for causing a computer to execute the above-described method for generating a row-of-teeth image.

[0009] According to one aspect of the present disclosure, it is possible to realize a row-of-teeth image generating device or the like that is capable of generating a row-of-teeth image with reduced discomfort.

[0010] Fig. 1 is a perspective view of an intraoral camera in a dentition image generation system according to an embodiment. Fig. 2 is a schematic configuration diagram of the dentition image generation system according to an embodiment. Fig. 3 is a block diagram showing the functional configuration of a mobile terminal according to an embodiment. Fig. 4 is a sequence diagram showing the operation of the dentition image generation system according to an embodiment. Fig. 5 is a diagram for explaining the processing of the dentition image generation system according to an embodiment.

[0011] (Background to the Invention of the Present Disclosure) Before describing the present disclosure, the background to the invention of the present disclosure will be described.

[0012] Patent Literature 1 discloses that an LED (Light Emitting Diode) with a central wavelength of 365 nm, 405 nm, or 470 nm is used as a light source of excitation light. When an affected area and its surroundings are photographed using such excitation light, the color tones of the plaque-free tooth area and its surroundings in the obtained image are close to the color of the excitation light. As a result, the color tones of the plaque-free tooth area and its surroundings are far from the actual color tones, and the user may feel uncomfortable with the obtained image. For example, when the obtained image is used to observe the condition of normal tissue around the affected area or to explain the condition to the user, the user may feel uncomfortable because the color tones are far from the actual color tones.

[0013] Furthermore, when adjusting the excitation light emitting unit and the illumination light emitting unit to improve the visibility of plaque, lesions, etc., the reproducibility of the color tone of each obtained image is low, and the user may feel uncomfortable with the obtained image.

[0014] As described above, there is room for improvement in generating a row-of-teeth image with reduced discomfort in the device of Patent Document 1. Therefore, the inventors of the present application have conducted extensive research into a row-of-teeth image generating device that can generate a row-of-teeth image with reduced discomfort, and have devised the row-of-teeth image generating device described below.

[0015] The teeth image generating device according to the first aspect of the present disclosure includes an acquisition unit that acquires a captured image obtained by photographing the surface of the teeth and dental plaque in the oral cavity irradiated with light including the wavelength range of blue light, a synthesis unit that generates a teeth image by synthesizing multiple teeth block images, which are partial teeth images based on the captured image, and a processing unit that performs white balance processing on the synthesized teeth image.

[0016] This allows for white balance adjustment with an appropriate gain for a row-of-teeth image composed of multiple row-of-teeth block images. In other words, the color tones of the combined row-of-teeth image can be made closer to the actual color tones. This makes it possible to generate a combined row-of-teeth image with reduced discomfort in color tones.

[0017] Also, for example, the teeth image generating device according to the second aspect may be the teeth image generating device according to the first aspect, and the processing unit may perform the white balance processing based on color information of the central tooth of the synthesized teeth image.

[0018] This allows the white balance of the central tooth to be adjusted with an appropriate gain. In other words, the color tone of the central tooth in the synthesized row-of-teeth image can be made closer to its actual color tone. Therefore, for example, if the area of ​​interest of the user is an area including the central tooth, the plaque area in that area can be effectively emphasized.

[0019] Also, for example, the teeth image generating device according to the third aspect may be the teeth image generating device according to the first aspect, and the processing unit may perform the white balance processing based on color information of the entire dental region of the teeth image after synthesis.

[0020] This allows white balance adjustment of the teeth in the combined row-of-teeth image with an appropriate gain (average gain), which means that the overall color tone of the teeth in the combined row-of-teeth image can be made closer to the actual color tone.

[0021] Also, for example, a teeth image generating device according to a fourth aspect may be a teeth image generating device according to any one of the first to third aspects, in which the processing unit adjusts the blue color level of the dental region of each of the plurality of teeth block images, and the synthesis unit synthesizes the plurality of teeth block images with the adjusted blue color level.

[0022] This makes it possible to align the blue color levels of the multiple row of teeth block images, thereby aligning the colors (color information) of the tooth regions in the row of teeth images after WB processing. For example, it is possible to prevent the user from feeling uncomfortable (uncomfortable due to inconsistent white colors) due to slight differences in the colors of the tooth regions in the multiple row of teeth block images.

[0023] Furthermore, for example, the dentition image generating device according to the fifth aspect may be a dentition image generating device according to any one of the first to fourth aspects, and may include a detection unit that detects plaque in an image based on the captured image, and a generation unit that generates the synthesized dentition image in which the plaque area detected by the detection unit is highlighted.

[0024] This allows the plaque region in the combined dentition image to be highlighted. For example, when such a combined dentition image is presented to a user, the user can easily confirm the plaque region.

[0025] Also, for example, the dentition image generating device according to the sixth aspect may be the dentition image generating device according to the fifth aspect, and may include a display unit that displays the synthesized dentition image in which the plaque area is highlighted.

[0026] This allows the user to be presented with a synthesized image of the rows of teeth in which the plaque areas are highlighted. For example, by taking an image of the rows of teeth after brushing and identifying the plaque areas, the user can be presented with the areas that have not been brushed.

[0027] Also, for example, a teeth image generating device according to the seventh aspect may be a teeth image generating device according to any one of the first to sixth aspects, and the plurality of teeth block images may include images of front teeth.

[0028] This allows an image of the right side teeth (e.g., the right molars) through to the front teeth to be combined with an image of the left side teeth (e.g., the left molars) through to the front teeth, based on the front teeth, thereby generating a combined image of the row of teeth from the right side to the left side.

[0029] Furthermore, for example, a teeth image generating device according to an eighth aspect is a teeth image generating device according to any one of the first to seventh aspects, and the surface of the teeth may include a side surface of the teeth.

[0030] This makes it possible to generate a row of teeth image after synthesis by photographing the side of the row of teeth, which is an row of teeth image with reduced discomfort in color tone.

[0031] Also, for example, a dentition image generating device according to a ninth aspect is a dentition image generating device according to any one of the first to eighth aspects, and the surface of the dentition may include an occlusal surface of the dentition.

[0032] This makes it possible to generate a row of teeth image after combining images of the occlusal surfaces of the row of teeth, as a row of teeth image in which the sense of incongruity due to color tones is reduced.

[0033] Furthermore, for example, a teeth image generating device according to a tenth aspect may be a teeth image generating device according to any one of the first to ninth aspects, and may include a saturation enhancement processing unit that generates a converted image by converting the combined teeth image into an HSV image, identifies a specific pixel area in which one or more pixels of the converted image that satisfy at least one of a first predetermined range for saturation, a second predetermined range for hue, and a third predetermined range for brightness are located, and performs saturation enhancement processing on the specific pixel area in the combined teeth image to generate the combined teeth image with enhanced saturation.

[0034] This allows specific pixel areas to be identified as plaque areas in the synthesized dentition image, and saturation enhancement processing is performed on the specific pixel areas, making it possible to generate a synthesized dentition image (dentition image with enhanced saturation S) in which plaque areas are easier to distinguish.

[0035] Furthermore, for example, a teeth image generating device according to an eleventh aspect may be a teeth image generating device according to any one of the first to tenth aspects, and may include a grayscale display processing unit that generates a converted image by converting the combined teeth image into an HSV image, identifies a specific pixel area in which one or more pixels of the converted image that satisfy at least one of a first predetermined range for saturation, a second predetermined range for hue, and a third predetermined range for brightness are located, detects an accumulation level distribution of fluorescent substances accumulated in the plaque from the brightness values ​​in the specific pixel area of ​​the converted image, and performs grayscale image processing according to the accumulation level distribution of the fluorescent substances detected for the specific pixel area in the combined teeth image, thereby generating the combined teeth image including a grayscale display.

[0036] This makes it possible to generate a combined row-of-teeth image that can notify the user of the concentration distribution of the fluorescent material, for example.

[0037] A method for generating a row-of-teeth image according to one aspect of the present disclosure includes acquiring a photographed image of the surface of the row of teeth and dental plaque in an oral cavity irradiated with light including a wavelength range of blue light, generating a row-of-teeth image by combining a plurality of row-of-teeth block images, which are partial row-of-teeth images based on the photographed image, and performing white balance processing on the combined row-of-teeth image.A program according to one aspect of the present disclosure is a program for causing a computer to execute the above-described row-of-teeth image generating method.

[0038] This provides the same effects as the above-described dentition image generating system.

[0039] These general or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or as any combination of the system, method, integrated circuit, computer program, or recording medium. The program may be pre-stored in the recording medium, or may be supplied to the recording medium via a wide area communication network including the Internet.

[0040] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0041] Furthermore, in this specification, terms indicating relationships between elements such as "identical," as well as numerical values ​​and numerical ranges, are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about several percent (or about 10%).

[0042] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not refer to the number or order of components unless otherwise specified, but are used for the purpose of avoiding confusion and distinguishing between components of the same type.

[0043] (Embodiment) Hereinafter, a teeth row image generating system and a teeth row image generating method according to this embodiment will be described with reference to Figs.

[0044] [1. Configuration of Teeth Image Generation System] First, the configuration of a teeth image generation system equipped with an intraoral camera according to this embodiment will be described with reference to Figures 1 to 3. Figure 1 is a perspective view of an intraoral camera 10 in the teeth image generation system according to this embodiment.

[0045] As shown in FIG. 1, the intraoral camera 10 has a toothbrush-shaped housing that can be handled with one hand, and the housing has a head portion 10a that is placed in the user's oral cavity when photographing the dentition, a handle portion 10b that the user holds, and a neck portion 10c that connects the head portion 10a and the handle portion 10b.

[0046] The imaging unit 21 captures images of the surfaces of the dentition and dental plaque in the oral cavity irradiated with light including the wavelength range of blue light. The surfaces of the dentition include at least one of the buccal (outer) side surface of the dentition, the lingual (inner) side surface of the dentition, and the occlusal surface of the dentition.

[0047] The photographing unit 21 is incorporated into the head unit 10a and the neck unit 10c. The photographing unit 21 has an image pickup element (not shown) and a lens (not shown) arranged on its optical axis LA.

[0048] The imaging element is a photographing device such as a CMOS (Complementary Metal Oxide Semiconductor) sensor or a CCD (Charge Coupled Device) element, and an image of the teeth is formed by a lens. The imaging element outputs a signal (image data) corresponding to the formed image to the outside. The image photographed by the imaging element is also referred to as an RGB image. The RGB image is an image sequence obtained by irradiating the dentition with blue light, and may be, for example, an image sequence of the side of the dentition or an image sequence of the occlusal surface of the dentition. The image sequence includes, for example, one or more images (e.g., time-series images) photographed along the direction of the dentition. The side of the dentition may be the lingual side or the buccal side.

[0049] The photographing unit 21 may further include an optical filter that blocks light of a color emitted from the illumination unit (illumination device) and transmits fluorescence emitted by plaque in response to the light. In this embodiment, the photographing unit 21 may include, as an optical filter, a blue light cut filter that cuts out blue wavelength light components contained in light incident on the image sensor. When light including a blue wavelength range is applied to teeth to detect plaque, if the light including the blue wavelength range is increased to enhance the excitation fluorescence of plaque, the blue pixel values ​​will become dominant over the red and green pixel values, and the entire RGB image will appear blue. To address this, a blue light cut filter cuts out a portion of the light including the blue wavelength range from the light before it enters the image sensor. Note that the photographing unit 21 does not necessarily have to include a blue light cut filter.

[0050] The intraoral camera 10 is also equipped with a plurality of first to fourth LEDs 23A to 23D as an illumination unit that irradiates light onto the teeth to be photographed during photography. The first to fourth LEDs 23A to 23D irradiate dental plaque with light of a color that causes the plaque to fluoresce (e.g., single-color light). The first to fourth LEDs 23A to 23D are, for example, blue LEDs that irradiate blue light including a wavelength having a peak at 405 nm (an example of a predetermined wavelength). Note that the first to fourth LEDs 23A to 23D are not limited to blue LEDs, and may be any light source that irradiates light including the wavelength range of blue light.

[0051] 2 is a schematic diagram of a dentition image generating system according to this embodiment. The dentition image generating system according to this embodiment is generally configured such that the imaging unit 21 captures fluorescence emitted by dental plaque in response to light from the illumination unit 23, and multiple images (e.g., a first dentition block image described below) based on the captured RGB images are combined (connected and combined) to generate a panoramic image in which teeth are aligned horizontally. The panoramic image represents the condition of at least a portion (e.g., the entire) of the user's mouth.

[0052] As shown in FIG. 2 , the dentition image generating system includes an intraoral camera 10 and a mobile terminal 50 .

[0053] The intraoral camera 10 includes a hardware unit 20, a signal processing unit 30, and a communication unit 40.

[0054] The hardware unit 20 is a physical element of the intraoral camera 10 and includes an imaging unit 21 , a sensor unit 22 , an illumination unit 23 , and an operation unit 24 .

[0055] The photographing unit 21 generates image data by photographing the teeth in the user's oral cavity. It can also be said that the photographing unit 21 generates image data by photographing the surface of the dentition and dental plaque in the oral cavity, which are irradiated with light of a predetermined wavelength that excites fluorescent substances contained in the plaque. The photographing unit 21 receives a control signal from the camera control unit 31, performs operations such as photographing in accordance with the received control signal, and outputs image data of a moving image or a still image obtained by photographing to the image processing unit 32. The photographing unit 21 has the above-mentioned image sensor, optical filter, and lens. The image data is generated, for example, based on light that has passed through the optical filter. Furthermore, the image data is an image showing multiple teeth, but it is sufficient that the image shows at least one tooth.

[0056] The sensor unit 22 detects external light incident on the imaging area of ​​the RGB image. For example, the sensor unit 22 detects whether external light is incident into the oral cavity. The sensor unit 22 is disposed, for example, near the imaging unit 21. The sensor unit 22 may be disposed, for example, in the head unit 10a of the intraoral camera 10, similar to the imaging unit 21. In other words, the sensor unit 22 is located in the user's oral cavity when the imaging unit 21 captures an image.

[0057] The illumination unit 23 irradiates light onto a region among multiple regions in the oral cavity that is to be photographed by the imaging unit 21. As is also known from quantitative visible light induced fluorescence (QLF) methods, when blue light is irradiated, a substance called porphyrin, which is excreted by bacteria in dental plaque, is known to fluoresce a reddish pink (excited fluorescence). In this embodiment, the illumination unit 23 irradiates blue light onto the region that is to be photographed by the imaging unit 21.

[0058] The illumination unit 23 has the above-mentioned first to fourth LEDs 23A to 23D. The first to fourth LEDs 23A to 23D irradiate the image capture area with light from different directions, for example. This makes it possible to prevent shadows from appearing in the image capture area.

[0059] Each of the first to fourth LEDs 23A to 23D is configured to be at least controllable in terms of dimming. Each of the first to fourth LEDs 23A to 23D may be configured to be controllable in terms of dimming and color adjustment. The first to fourth LEDs 23A to 23D are arranged to surround the imaging unit 21.

[0060] The illumination unit 23 controls the illumination intensity (light emission intensity) according to the photographing area. The illumination intensity of each of the first to fourth LEDs 23A to 23D may be controlled uniformly, or may be controlled to be different from one another. The number of LEDs included in the illumination unit 23 is not particularly limited, and may be one, or five or more. Furthermore, the illumination unit 23 is not limited to having an LED as a light source, and may include other light sources.

[0061] The operation unit 24 receives operations from the user. The operation unit 24 is configured with, for example, push buttons, but may also be configured to receive operations by voice or the like.

[0062] The hardware unit 20 may further include a battery (e.g., a secondary battery) that supplies power to each component of the intraoral camera 10, a coil for wireless charging by an external charger connected to a commercial power source, and an actuator necessary for at least one of composition adjustment and focus adjustment.

[0063] The signal processing unit 30 has functional components implemented by a CPU (Central Processing Unit) or an MPU (Micro Processor Unit) that execute various processes described below, and a memory unit 35 such as a ROM (Read Only Memory) or RAM (Random Access Memory) that stores programs for causing the functional components to execute various processes. Specifically, the signal processing unit 30 has a camera control unit 31, an image processing unit 32, a control unit 33, a lighting control unit 34, and the memory unit 35.

[0064] The camera control unit 31 is mounted on, for example, the handle unit 10b of the intraoral camera 10 and controls the imaging unit 21. The camera control unit 31 controls at least one of the aperture and the shutter speed of the imaging unit 21 in response to a control signal from the image processing unit 32, for example.

[0065] The image processing unit 32 is mounted on, for example, the handle unit 10b of the intraoral camera 10, acquires the RGB image (image data) captured by the imaging unit 21, performs image processing on the acquired RGB image, and outputs the processed RGB image to the camera control unit 31 and the control unit 33. The image processing unit 32 may also output the processed RGB image to the memory unit 35, and store the processed RGB image in the memory unit 35.

[0066] The image processing unit 32 is configured by, for example, a circuit, and performs image processing such as noise removal, edge enhancement, etc. on the RGB image. Note that the noise removal, edge enhancement, etc. may be performed by the mobile terminal 50.

[0067] The RGB image output from the image processing unit 32 (the RGB image after image processing) may be transmitted to the mobile terminal 50 via the communication unit 40, and an image based on the transmitted RGB image (for example, a third dentition image described below) may be displayed on the display unit 56 of the mobile terminal 50. This allows the user to be presented with an image based on the RGB image.

[0068] The control unit 33 is a control device that controls the signal processing unit 30. The control unit 33 controls each component of the signal processing unit 30 based on the detection result of the sensor unit 22, such as external light.

[0069] The illumination control unit 34 is mounted, for example, on the handle portion 10b of the intraoral camera 10 and controls the turning on and off of the first to fourth LEDs 23A to 23D. The illumination control unit 34 is configured, for example, by a circuit. For example, when a user performs an operation on the display unit 56 of the mobile terminal 50 to start the intraoral camera 10, a corresponding signal is transmitted from the mobile terminal 50 to the signal processing unit 30 via the communication unit 40. The illumination control unit 34 of the signal processing unit 30 turns on the first to fourth LEDs 23A to 23D based on the received signal.

[0070] In addition to the above programs, the memory unit 35 stores RGB images (image data) captured by the image capturing unit 21. The memory unit 35 is realized by, for example, a semiconductor memory such as a ROM or a RAM, but is not limited to this.

[0071] The communication unit 40 is a wireless communication module for wirelessly communicating with the mobile terminal 50. The communication unit 40 is mounted, for example, on the handle portion 10b of the intraoral camera 10, and performs wireless communication with the mobile terminal 50 based on a control signal from the signal processing unit 30. The communication unit 40 performs wireless communication with the mobile terminal 50 in accordance with an existing communication standard such as Wi-Fi (registered trademark) or Bluetooth (registered trademark). Via the communication unit 40, an RGB image is transmitted from the intraoral camera 10 to the mobile terminal 50, and an operation signal is transmitted from the mobile terminal 50 to the intraoral camera 10.

[0072] The mobile device 50 displays the plaque region in the second dentition image including two or more teeth based on an RGB image of the dentition surface and plaque that have fluorescently reacted when the teeth are irradiated with light including a wavelength range of blue light. The mobile device 50 also functions as a user interface for the dentition image generation system. The mobile device 50 is an example of a dentition image generation device.

[0073] FIG. 3 is a block diagram showing the functional configuration of the mobile terminal 50 according to this embodiment.

[0074] 3 , the mobile terminal 50 includes an acquisition unit 51, a processing unit 52, a synthesis unit 53, a detection unit 54, a generation unit 55, and a display unit 56. The mobile terminal 50 includes a processor, a memory, and the like. The memory is a ROM, a RAM, or the like, and can store a program executed by the processor. The acquisition unit 51, the processing unit 52, the synthesis unit 53, the detection unit 54, and the generation unit 55 are realized by a processor or the like that executes a program stored in the memory. The mobile terminal 50 may be realized, for example, by a smartphone or tablet terminal capable of wireless communication.

[0075] The acquisition unit 51 acquires RGB images from the intraoral camera 10. Specifically, the acquisition unit 51 acquires images (image sequence) showing multiple teeth generated by the imaging unit 21. The RGB images are images obtained by the intraoral camera 10 photographing teeth that are undergoing a fluorescent reaction by irradiating the teeth with light including a wavelength range of blue light. The acquisition unit 51 is configured to include, for example, a wireless communication module that performs wireless communication.

[0076] Here, the RGB image acquired by the acquisition unit 51 has a bluish tint overall. This is because when irradiating teeth with light including a blue wavelength range to detect plaque, the illumination unit 23 intensifies light including a blue wavelength range to enhance the excitation fluorescence of plaque. As a result, blue pixel values ​​(B) are dominant compared to red pixel values ​​(R) and green pixel values ​​(G). In other words, a color cast occurs in the RGB image acquired by the acquisition unit 51. In this state, it is difficult to clearly present the plaque adhesion state to the user. Therefore, the mobile terminal 50 performs predetermined image processing on the RGB image acquired by the acquisition unit 51, as described below, to execute processing to clearly present the plaque adhesion state to the user.

[0077] The processing unit 52 generates a plurality of first row-of-teeth block images, which are partial row-of-teeth images, from the RGB image (image sequence) generated by the imaging unit 21, and performs image processing on an image based on the generated plurality of first row-of-teeth block images. In this embodiment, the processing unit 52 performs image processing on each of the plurality of first row-of-teeth block images and each of the first row-of-teeth image or second row-of-teeth image obtained by combining the plurality of first row-of-teeth block images.

[0078] The first tooth row block image is an image obtained by cutting out a predetermined range including the center of the angle of view from an image captured at a certain photographing position. Each of the multiple first tooth row block images is an image based on an image captured at a different photographing position (or photographing direction).

[0079] Furthermore, each of the multiple first teeth block images is an image including at least one tooth or interdental space. The first teeth block image may be, for example, an image of at least one tooth or interdental space photographed from the front. The first teeth block images may be the same or different in size (image size). Furthermore, in each of the first teeth block images, at least a portion of the dental region shown in that first teeth block image overlaps with a portion of the dental region shown in at least one other first teeth block image.

[0080] The RGB image may be the first row of teeth block image itself, or the first row of teeth block image may be generated by dividing the RGB image so that parts of the image overlap with each other.

[0081] The processing unit 52 performs exposure correction processing on the multiple first dentition block images as image processing before compositing by the compositing unit 53. The exposure correction processing adjusts the blue level of each tooth region by multiplying each of the R, G, and B components by an equal gain. The processing unit 52 adjusts the blue level so that the blue levels of the tooth regions of each of the multiple first dentition block images approach (e.g., match) each other. For example, when the multiple first dentition block images are arranged in dentition order, the processing unit 52 adjusts the color of each tooth of one or more other first dentition block images so that the color of the tooth (reference tooth) located in the center of the first dentition block image is unified. The reference tooth may be, for example, the tooth located in the center of the angle of view in the RGB image captured by the imaging unit 21. For example, since light from the illumination unit 23 may be unevenly irradiated at both ends of the angle of view, adjusting the blue level makes it possible to reproduce the color of the tooth illuminated similarly to the central tooth. The adjustment of the blue color level may be performed only on the tooth region, or may be performed on the entire first row of teeth block image (for example, the region including the teeth and gums).

[0082] Furthermore, the processing unit 52 performs WB (White Balance) processing on the row-of-teeth image (first row-of-teeth image or second row-of-teeth image) as image processing after the combining unit 53. WB processing is processing to adjust the color balance of an image by multiplying each of the R, G, and B components by a different gain (white balance gain). WB processing is processing to adjust the gains of at least two color components of the red, green, and blue components of the image to be processed so that, for example, the red pixel average value of multiple red pixel values ​​of multiple pixels constituting the tooth region of the first row-of-teeth block image to be processed, the green pixel average value of multiple green pixel values ​​of the multiple pixels, and the blue pixel average value of multiple blue pixel values ​​of the multiple pixels become closer to each other (for example, become equal).

[0083] The processing unit 52 performs WB processing on the row-of-teeth image, assuming that the tooth region shown in the row-of-teeth image is a white region. The processing unit 52 performs WB processing on the row-of-teeth image based on the color (color information) of the tooth region shown in the row-of-teeth image. The processing unit 52 may perform WB processing based on the color (color information) of an arbitrary tooth (e.g., the tooth shown in the center of the row-of-teeth image) or on a statistical value (e.g., the average value, median, etc.) of the color (color information) of the tooth region. The processing unit 52 may perform WB processing by multiplying the entire tooth region by a gain calculated based on the arbitrary tooth or the statistical value. Furthermore, for example, if the blue level is adjusted before composition by the composition unit 53, the blue level of the composited row-of-teeth image can be made uniform, making it possible to perform white balance processing on the tooth regions of the row-of-teeth image collectively. "Completely" means that the gain used for white balance processing is the same.

[0084] This allows the tooth region to be displayed in white (achromatic color). In other words, it is easier to reproduce the actual color of the user's teeth. This not only reduces the sense of incongruity in the image, but also makes it easier to highlight the plaque region. Furthermore, when white balance processing is performed collectively, it is possible to unify the color of the tooth region to the same color (white). For example, it is possible to prevent the user from feeling uncomfortable about the color of the tooth region.

[0085] The processing unit 52 only needs to adjust the blue level and perform at least the WB processing.

[0086] The tooth region shown in the row-of-teeth image may be the region of a natural tooth in the teeth shown in the row-of-teeth image. That is, the processing unit 52 may perform WB processing assuming that the natural tooth region is a white region (for example, using the color (color information) of the natural tooth region shown in the row-of-teeth image as a reference). The natural tooth region may be the natural tooth region of a single tooth shown in the row-of-teeth image, the natural tooth region of a specific tooth, or the natural tooth region of multiple teeth. When the natural tooth regions of multiple teeth are used as a reference, a statistical value of the color (e.g., chromaticity) of the natural tooth region of each of the multiple teeth may be used in WB processing. The statistical value may be, for example, an average value, but may also be a maximum value, minimum value, mode, median, etc.

[0087] It is known that when natural teeth are irradiated with excitation light, excitation fluorescence is emitted from the dentin, which passes through the enamel and fluoresces green. It is also known that fillings (e.g., metal inlays) in caries treatment scars do not emit excitation fluorescence under blue LED light and are imaged darkly (at low brightness) by a camera. As described above, it is also known that plaque (plaque regions) fluoresce reddish pink (excitation fluorescence) when irradiated with blue light. Based on these facts, the processing unit 52 can detect natural teeth excluding caries treatment scars and plaque from the dentition image.

[0088] The processing unit 52 may further identify the type of tooth (e.g., a specific tooth) included in the image from the first dentition block image, the first dentition image, or the dentition image (the second dentition image or the third dentition image). Identifying the type of tooth may mean identifying whether the tooth is an incisor, canine, or molar, or whether the tooth is a central incisor, lateral incisor, canine, first premolar, second premolar, first molar, second molar, or third molar (wisdom tooth). The processing unit 52 may also identify the region of the oral cavity (upper jaw, lower jaw, left or right) in which the tooth is located. The method by which the processing unit 52 identifies the type of tooth is not particularly limited, and may include, for example, a method using a machine learning model, a method using pattern matching, or any other known method. The machine learning model is a learning model that is trained to output the type of tooth shown in an image containing teeth when the image is input. In the method using pattern matching, an image showing each tooth of a standard shape may be used as a reference, or an image of the teeth in the user's oral cavity taken in advance may be used as a reference. Furthermore, the processing unit 52 may present the user with information identifying the teeth to be photographed before photographing, and determine that the teeth shown in the image acquired after the information is presented are the teeth to be photographed, or may prompt the user to input which teeth are included in the acquired image, and determine that the input type of teeth is shown in the image.

[0089] The combining unit 53 generates a single row-of-teeth image (panoramic image) in which multiple teeth are arranged by combining multiple first row-of-teeth block images whose blue color levels have been adjusted by the processing unit 52. In this embodiment, the combining unit 53 combines the multiple row-of-teeth block images whose blue color levels have been adjusted using a stitching process, but the combining method is not limited to this. The stitching process may be performed using, for example, the tooth outlines.

[0090] The stitching process here refers to a process of combining multiple images (here, multiple first tooth-row block images) having overlapping regions to generate one or more tooth-row images. In the stitching process, the multiple first tooth-row block images are first arranged on a two-dimensional plane so that their overlapping portions are aligned. Then, the multiple first tooth-row block images are scaled (magnified), positioned, and oriented so that at least some of the feature points and surface points appear in the same location on the two-dimensional grid. In this way, the multiple first tooth-row block images are aligned where they are to be aligned. That is, the multiple first tooth-row block images are aligned to represent a series of adjacent teeth and are aligned to match the positions of the teeth.

[0091] Note that any type of feature detection algorithm may be used to detect the feature points, including a scale-invariant feature transform (SIFT) or a speed-up robust feature algorithm (SURF). In this embodiment, feature points may be provided on the contour portion of the tooth region. Furthermore, the location of the surface point can be calculated by measuring the distance between the focal points of the viewpoints at which the two first dentition block images including the overlapping portion were taken, extracting the angles of the optical axes at each viewpoint, and using a triangle measure based on a common position in the image.

[0092] In the following description, an example will be described in which the synthesis unit 53 synthesizes a second row-of-teeth image P20 (see FIG. 5 , which will be described later) showing the left molar through the right molar. However, the present invention is not limited to this example, and the second row-of-teeth image P20 may be generated to include only a portion of the teeth, such as two or more teeth. In this case, the synthesis unit 53 may include information regarding the type or intraoral position of the portion of the teeth in the second row-of-teeth image P20. This allows the user to be notified of which region of the oral cavity the second row-of-teeth image P20 represents. The type of tooth or its position in the oral cavity (e.g., upper jaw, lower jaw, left or right region, etc.) is identified by the processing unit 52.

[0093] The detection unit 54 detects plaque (plaque region) on the image on which WB processing has been performed (an example of an image based on a captured image). In this embodiment, the detection unit 54 detects plaque based on color information of the tooth region in the row-of-teeth image generated by the synthesis unit 53. The color information includes lightness V, hue H, and saturation S. The detection unit 54 detects plaque, for example, based on lightness V. The detection unit 54 detects, for example, a region where lightness V is equal to or greater than a threshold value as a plaque region.

[0094] In addition, the detection unit 54 may input a dentition image that has undergone WB processing and detect plaque (plaque area) that appears in the dentition image using a machine learning model that has been trained to output plaque (plaque area) that appears in the dentition image.

[0095] The detection unit 54 may detect plaque before the combining unit 53 performs the combining, or after the combining unit 53 performs the combining and before the WB processing is performed by the processing unit 52. In other words, the detection unit 54 may detect plaque using a color-cast image (an example of an image based on a captured image).

[0096] The generating unit 55 is a processing unit for generating a row-of-teeth image (for example, a third row-of-teeth image described later) in which the plaque region detected by the detecting unit 54 is highlighted. The generating unit 55 highlights the detected plaque region in the row-of-teeth image generated by the combining unit 53. For example, the generating unit 55 superimposes a highlight on the plaque region in the row-of-teeth image.

[0097] If the detection unit 54 detects plaque before the WB processing, the generation unit 55 may superimpose a highlight on the plaque region of the third row-of-teeth image after the WB processing.

[0098] The display unit 56 is a display device included in the mobile terminal 50, and displays the image generated by the generation unit 55. The display unit 56 may be realized by, for example, a liquid crystal display panel.

[0099] The detection unit 54 and the generation unit 55 may function as a saturation enhancement processing unit that performs saturation enhancement processing. For example, the detection unit 54 may generate a converted image by converting the row-of-teeth image (e.g., the third row-of-teeth image) that has been combined by the combination unit 53 and subjected to WB processing into an HSV image, and identify a specific pixel region in which one or more pixels in the converted image satisfy at least one of the following conditions: saturation S within a first predetermined range (e.g., 30 to 80 in 8-bit representation), hue H within a second predetermined range (e.g., 140 to 170 in 8-bit representation), and lightness V within a third predetermined range (e.g., 100 to 180 in 8-bit representation). The generation unit 55 may also generate a row-of-teeth image in which saturation S is enhanced by performing saturation enhancement processing on the specific pixel region in the row-of-teeth image (e.g., the third row-of-teeth image). The HSV image may be generated, for example, by converting the color space of the row-of-teeth image into the HSV space. The display unit 56 may also display a row-of-teeth image that has been subjected to saturation enhancement processing.

[0100] The first, second, and third predetermined ranges are not limited to the above-mentioned ranges, and may be determined by comparing the actual plaque and tooth regions with the HSV image. For example, the ranges of the values ​​of lightness V, hue H, and saturation S may be determined by administering a plaque stain and comparing the degree of staining by the plaque stain.

[0101] The detection unit 54 and the generation unit 55 may function as a grayscale display processing unit that performs grayscale image processing according to the concentration distribution (accumulation level distribution) of the fluorescent substance. For example, the detection unit 54 may detect the concentration distribution of the fluorescent substance accumulated in plaque from the value of brightness V in a specific pixel region of the converted image. Furthermore, the generation unit 55 may generate a row-of-teeth image (e.g., a third row-of-teeth image) including a grayscale display by performing grayscale image processing according to the concentration distribution of the fluorescent substance detected for the specific pixel region in the row-of-teeth image.

[0102] As blue light passes through each layer, porphyrins in the plaque are excited, generating red fluorescence. Furthermore, the intensity of the fluorescence is thought to indicate the accumulation of fluorescent substances (porphyrins), rather than reflecting the current bacterial flora. In other words, the more fluorescent substances are accumulated, the stronger the red fluorescence. In other words, the level of porphyrin accumulation increases as the plaque matures. Therefore, the fluorescence intensity of mature plaque is stronger than that of young plaque.

[0103] The detection unit 54 detects the accumulation level (concentration or density) of the fluorescent substance by comparing the intensity of red fluorescence per unit area of ​​the plaque region.

[0104] As described above, a plaque region may be extracted from one or more pixels in the HSV image that satisfy at least one of the following conditions: saturation S within a first predetermined range, hue H within a second predetermined range, and brightness V within a third predetermined range.

[0105] Furthermore, in an image that has undergone WB processing, in the plaque region, the lightness V is determined by the R value, regardless of the hue H and saturation S.

[0106] It is also known that porphyrin, a fluorescent substance in dental plaque, has a fluorescence wavelength of 600 nm to 740 nm, with a peak fluorescence wavelength of 630 nm. In other words, the concentration of porphyrin accumulated in the dental plaque region can be evaluated by detecting the brightness V value of the HSV image of the dental plaque region.

[0107] [2. Operation of the row-of-teeth image generating system] Next, the operation of the row-of-teeth image generating system configured as described above will be described with reference to Figs. 4 and 5. Fig. 4 is a sequence diagram showing the operation of the row-of-teeth image generating system (row-of-teeth image generating method) according to this embodiment. The process shown in Fig. 4 is executed by the mobile terminal 50. Note that the process shown in Fig. 4 is, for example, a process performed in real time, and is performed each time one frame or multiple frames of image data are obtained. Fig. 5 is a diagram for explaining the process of the row-of-teeth image generating system according to this embodiment. Note that in Fig. 5, color-cast images are indicated by diagonal hatching.

[0108] 4, image data is generated by a user photographing the teeth and gums in his or her oral cavity using the intraoral camera 10 (S101). This image data is obtained by, for example, photographing the teeth that are fluorescently reacting by irradiating them with light including a wavelength range of blue light.

[0109] Next, the communication unit 40 of the intraoral camera 10 transmits the captured image data to the mobile terminal 50, and the acquisition unit 51 of the mobile terminal 50 acquires the image data (S102). The image data may be a video or one or more still images. Furthermore, when the image data is a video or multiple still images, the image data may be transmitted for each frame of the video or for each still image. Furthermore, when the image data is a video, the image data may be transmitted for each multiple frame.

[0110] Furthermore, the image data may be transmitted in real time, or may be transmitted all at once after a series of photographs (for example, photographs of all teeth in the oral cavity) have been taken.

[0111] The processing unit 52 of the mobile terminal 50 adjusts the blue color level of the received image data (S103). The processing unit 52 may multiply each of the R, G, and B components by a different gain so that the blue color levels of the tooth regions of each of the plurality of first tooth row block images, which are partial tooth row images based on the image data, become closer to each other.

[0112] 5A, each of the first tooth row block images P1 to P5 is an image that has not been subjected to WB processing, and each of the first tooth row block images P1 to P5 is an image in which the blue color level has been adjusted.

[0113] Referring again to FIG. 4, next, the synthesis unit 53 of the mobile terminal 50 synthesizes a plurality of first tooth row block images P1 to P5 for which no WB processing has been performed and for which the blue color level has been adjusted (S104).

[0114] 5A and 5B, the synthesis unit 53 performs a stitching process on the first row of teeth block images P1, P2, and P3 to generate a first row of teeth image P11 that includes the first row of teeth block images P1 and P2 and at least a portion of the first row of teeth block image P3. The synthesis unit 53 also performs a stitching process on the first row of teeth block images P3, P4, and P5 to generate a first row of teeth image P12 that includes at least a portion of the first row of teeth block image P3 and the first row of teeth block images P4 and P5. The first row of teeth images P11 and P12 are images in which at least a portion of the dental region overlaps. In the example of FIG. 5, the dental region of the first row of teeth block image P3 overlaps at least a portion of the first row of teeth images P11 and P12.

[0115] The processing unit 52 also performs stitching processing so that the first row-of-teeth image P11 includes the center of the angle of view of each of the first row-of-teeth block images P1 to P3. Taking the first row-of-teeth image P11 as an example, the processing unit 52 performs stitching processing so that the first row-of-teeth image P11 includes the center of the angle of view of each of the first row-of-teeth block images P1 to P3. The first row-of-teeth image P11 thus generated is an image in which light hits each tooth from the front, making it less likely to produce shadows and making it easier to see the spaces between the teeth.

[0116] Here, the first tooth row block image P3 may be an image including the two lower front teeth, for example, an image including the space between the two front teeth. In this case, the first tooth row image P11 may be, for example, a panoramic image showing the area from the left back tooth to the front teeth, and the first tooth row image P12 may be, for example, a panoramic image showing the area from the right back tooth to the front teeth.

[0117] In addition, the image including the spaces between the front teeth may be, for example, an image taken after an announcement such as "Please take a picture of your front teeth" is made when taking a picture using the photographing unit 21, or it may be an image in which the user has input that it is an image of the front teeth.

[0118] The number of first row-of-teeth images generated by the combining unit 53 is not particularly limited, and may be three or more.

[0119] The synthesis unit 53 then performs a stitching process on the two first row-of-teeth images P11 and P12 to generate a second row-of-teeth image P20. The second row-of-teeth image P20 is a panoramic image formed by synthesizing multiple first row-of-teeth block images P1 to P5. The second row-of-teeth image P20 is a panoramic image that shows at least a portion of the row of teeth in the user's oral cavity, and may be, for example, a panoramic image that shows the user's left molar to right molar. The second row-of-teeth image P20 is an example of a synthesized row-of-teeth image.

[0120] The synthesis unit 53 may generate the second row-of-teeth image P20 directly based on the plurality of first row-of-teeth block images P1 to P5, i.e., the first row-of-teeth images P11 and P12 do not have to be generated.

[0121] 4 again, next, the processing unit 52 of the mobile terminal 50 performs image processing on the second row-of-teeth image P20 synthesized by the synthesis unit 53 (S105). In step S105, the processing unit 52 performs at least WB processing on the second row-of-teeth image P20.

[0122] 5(c) and 5(d), the processing unit 52 generates a third row-of-teeth image P30 by performing WB processing on the second row-of-teeth image P20 based on color information of the tooth region of the second row-of-teeth image P20. The processing unit 52 may perform WB processing based on color information of the central tooth in the second row-of-teeth image P20 (e.g., the tooth shown in the first row-of-teeth block image P3). For example, the processing unit 52 may perform WB processing based on color information of only the central tooth in the second row-of-teeth image P20 (e.g., the tooth shown in the first row-of-teeth block image P3).

[0123] The third row-of-teeth image P30 is composed of multiple second row-of-teeth block images P31 to P35. The second row-of-teeth block image P31 corresponds to the image obtained by performing white balance processing on the first row-of-teeth block image P1, the second row-of-teeth block image P32 corresponds to the image obtained by performing white balance processing on the first row-of-teeth block image P2, the second row-of-teeth block image P33 corresponds to the image obtained by performing white balance processing on the first row-of-teeth block image P3, the second row-of-teeth block image P34 corresponds to the image obtained by performing white balance processing on the first row-of-teeth block image P4, and the second row-of-teeth block image P35 corresponds to the image obtained by performing white balance processing on the first row-of-teeth block image P5.

[0124] 4 again, the detection unit 54 of the mobile device 50 then detects plaque in the third dentition image P30 (S106). The detection unit 54 detects the presence or absence of plaque, but may also detect, for example, the concentration distribution of fluorescent substances, i.e., the level of plaque accumulation.

[0125] Next, the generation unit 55 of the mobile terminal 50 generates an image in which the plaque region detected by the detection unit 54 is highlighted (S107). In this embodiment, the generation unit 55 generates an image in which a highlight display indicating the plaque region is superimposed on the third row-of-teeth image P30, but it may also generate an image in which a grayscale display corresponding to the concentration distribution of the fluorescent substance is superimposed on the third row-of-teeth image P30.

[0126] Next, the display unit 56 of the mobile terminal 50 displays the image generated by the generation unit 55 (S108).

[0127] By using such a dentition image generation system, a user can take an image of the inside of their own oral cavity with the intraoral camera 10 and check the condition of the inside of their oral cavity as a panoramic image displayed on the mobile terminal 50. Furthermore, the concentration distribution of the fluorescent substance is displayed on the displayed panoramic image, allowing the user to easily check the health condition of their own teeth.

[0128] In addition, the mobile terminal 50 performs white balance processing, so that it can generate a third dentition image P30 with the plaque area superimposed (e.g., highlighted) regardless of the color of light emitted by the lighting unit 23 of the intraoral camera 10.

[0129] Furthermore, the mobile terminal 50 may generate a three-dimensional model of a plurality of teeth in the oral cavity from a plurality of captured image data, and may display an image based on the generated three-dimensional model.

[0130] The detector 54 may detect plaque on the first row-of-teeth images P11 and P12 instead of detecting plaque on the second row-of-teeth image P20.

[0131] Although an example in which the mobile terminal 50 processes images of teeth has been described above, some or all of this processing may be performed by the intraoral camera 10 .

[0132] Other Embodiments Although the row-of-teeth image generating system according to the embodiment of the present disclosure has been described above, the present disclosure is not limited to this embodiment.

[0133] For example, in the above embodiment, an example has been described in which the intraoral camera 10 is used primarily for photographing teeth, but the intraoral camera 10 may also be an oral care device equipped with a camera, such as an oral irrigator equipped with a camera.

[0134] Furthermore, in the above embodiment, the mobile terminal 50 is exemplified as the user's information terminal, but the information terminal may be a stationary information terminal.

[0135] Furthermore, in the above embodiment, the multiple first tooth row block images may be, for example, images taken after an announcement is made regarding the tooth position or tooth type when photographing with the photographing unit 21, or may be images in which the position of the tooth is input by a user or the like.

[0136] Furthermore, each processing unit included in the dentition image generating system according to the above embodiment is typically realized as an LSI, which is an integrated circuit. These may be individually implemented as single chips, or some or all of them may be integrated into a single chip.

[0137] Furthermore, the integrated circuit is not limited to an LSI, but may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI may also be used.

[0138] In each of the above embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0139] The division of functional blocks in the block diagram is an example, and multiple functional blocks may be realized as a single functional block, one functional block may be divided into multiple blocks, or some functions may be moved to another functional block.Furthermore, the functions of multiple functional blocks having similar functions may be processed in parallel or in time-sharing by a single piece of hardware or software.

[0140] Furthermore, the mobile terminal 50 according to the above embodiment may be realized as a single device or may be realized by multiple devices. When the mobile terminal 50 is realized by multiple devices, the components of the mobile terminal 50 may be distributed among the multiple devices in any manner. For example, at least some of the functions of the mobile terminal 50 may be realized by the intraoral camera 10 (e.g., the signal processing unit 30). When the mobile terminal 50 is realized by multiple devices, the communication method between the multiple devices is not particularly limited and may be wireless communication or wired communication. Furthermore, wireless communication and wired communication may be combined between the devices.

[0141] The present disclosure may also be realized as a dentition image generation method executed by a dentition image generation system, or as an intraoral camera, a mobile terminal, or a cloud server included in the dentition image generation system.

[0142] The order in which the steps are executed in the sequence diagram is merely an example for specifically explaining the present disclosure, and any order other than the above may be used. Also, some of the steps may be executed simultaneously (in parallel) with other steps.

[0143] Furthermore, one aspect of the present disclosure may be a computer program that causes a computer to execute each of the characteristic steps included in the dentition image generating method shown in FIG. 4 .

[0144] Furthermore, for example, the program may be a program to be executed by a computer. Another aspect of the present disclosure may be a computer-readable non-transitory recording medium on which such a program is recorded. For example, such a program may be recorded on a recording medium and distributed or circulated. For example, the distributed program may be installed in a device having another processor, and the program may be executed by the processor, thereby causing the device to perform each of the above processes.

[0145] Although the dentition image generating system according to one or more aspects has been described based on the embodiments, the present disclosure is not limited to these embodiments. As long as it does not deviate from the spirit of the present disclosure, various modifications conceivable by a person skilled in the art to the present embodiments, or configurations constructed by combining components of different embodiments, may also be included within the scope of one or more aspects.

[0146] The present disclosure is applicable to a dentition image generation system.

[0147] REFERENCE SIGNS LIST 10 Intraoral camera 10a Head 10b Handle 10c Neck 20 Hardware 21 Photography unit 22 Sensor 23 Illumination unit 23A First LED 23B Second LED 23C Third LED 23D Fourth LED 24 Operation unit 30 Signal processing unit 31 Camera control unit 32 Image processing unit 33 Control unit 34 Illumination control unit 35 Memory unit 40 Communication unit 50 Portable terminal (dentition image generating device) 51 Acquisition unit 52 Processing unit 53 Synthesis unit 54 Detection unit (saturation emphasis processing unit, shading display processing unit) 55 Generation unit (saturation emphasis processing unit, shading display processing unit) 56 Display unit P1, P2, P3, P4, P5 First dentition block image P11, P12 First dentition image P20 Second dentition image (dentition image) P30 Third dentition image P31, P32, P33, P34, P35 Second dentition block image

Claims

1. A dentition image generating device comprising: an acquisition unit that acquires a captured image obtained by photographing the surface of the dentition and dental plaque in the oral cavity irradiated with light including a wavelength range of blue light; a synthesis unit that generates a dentition image by synthesizing a plurality of dentition block images, which are partial dentition images based on the captured images; and a processing unit that performs white balance processing on the synthesized dentition image.

2. The device for generating a row-of-teeth image according to claim 1, wherein the processing unit performs the white balance processing based on color information of a central tooth of the row-of-teeth image after synthesis.

3. The device for generating a row-of-teeth image according to claim 1, wherein the processing unit performs the white balance processing based on color information of the entire tooth region of the row-of-teeth image after synthesis.

4. A dentition image generating device as claimed in any one of claims 1 to 3, wherein the processing unit adjusts the blue color level of the tooth region of each of the plurality of dentition block images, and the synthesis unit synthesizes the plurality of dentition block images with the blue color level adjusted.

5. A dentition image generating device as claimed in any one of claims 1 to 3, comprising: a detection unit which detects plaque in an image based on the captured image; and a generation unit which generates a composite dentition image in which the plaque area detected by the detection unit is highlighted.

6. The dentition image generating device according to claim 5, further comprising a display unit for displaying the synthesized dentition image in which the plaque region is highlighted.

7. The dentition image generating device according to any one of claims 1 to 3, wherein the plurality of dentition block images includes an image of anterior teeth.

8. A dentition image generating device according to any one of claims 1 to 3, wherein the surface of the dentition includes a side surface of the dentition.

9. A dentition image generating device according to any one of claims 1 to 3, wherein the surfaces of the dentition include occlusal surfaces of the dentition.

10. A teeth image generating device as claimed in any one of claims 1 to 3, comprising a saturation emphasis processing unit that generates a converted image by converting the synthesized teeth image into an HSV image, identifies a specific pixel area in which one or more pixels of the converted image that satisfy at least one of a first predetermined range for saturation, a second predetermined range for hue, and a third predetermined range for brightness are located, and performs saturation emphasis processing on the specific pixel area in the synthesized teeth image to generate the synthesized teeth image with enhanced saturation.

11. A teeth image generating device as claimed in any one of claims 1 to 3, comprising a shade display processing unit that generates a converted image by converting the synthesized teeth image into an HSV image, identifies a specific pixel area in which one or more pixels of the converted image that satisfy at least one of a first predetermined range for saturation, a second predetermined range for hue, and a third predetermined range for brightness are located, detects an accumulation level distribution of fluorescent substances accumulated in the plaque from the brightness values ​​in the specific pixel area of ​​the converted image, and generates the synthesized teeth image including a shade display by performing shade image processing according to the accumulation level distribution of the fluorescent substances detected for the specific pixel area in the synthesized teeth image.

12. A method for generating a dentition image, comprising: acquiring an image obtained by photographing the surface of the dentition and dental plaque inside the oral cavity irradiated with light including a wavelength range of blue light; generating a dentition image by synthesizing a plurality of dentition block images, which are partial dentition images based on the photographed image; and performing white balance processing on the synthesized dentition image.

13. A program for causing a computer to execute the dentition image generating method according to claim 12.

Images