Image processing device, medical system, method for operating image processing device, and program

Abstract

Provided are an image processing device, a medical system, a method for operating an image processing device, and a program with which it is possible to emphasize or suppress each of a microscopic structure and a microscopic blood vessel in an image, regardless of the observation distance. This medical device comprises a processor, wherein the processor acquires an image signal generated by imaging return light from a living body tissue and generates a display image by performing, on the image signal on the basis of localized contrast information in the image signal, at least one of an emphasizing process for emphasizing at least one of microscopic structure information regarding a microscopic structure and microscopic blood vessel information regarding a microscopic blood vessel, and a suppression process for suppressing at least one of microscopic structure information regarding a microscopic structure and microscopic blood vessel information regarding a microscopic blood vessel in the living body tissue.

Description

Image processing device, medical system, and operation method and program for image processing device

[0001] The present disclosure relates to an image processing device, a medical system, an operation method for an image processing device, and a program.

[0002] In recent years, endoscopic systems have been known to use "VS (Vessel Plus Surface) Classification," which focuses on the fine mucosal structure of a subject for diagnosis. This "VS Classification" requires highlighting both the microvascular structure (microvascular pattern; V) in the mucosal surface and the surface fine structure (microvascular pattern; S) of the mucosal surface, in order to independently diagnose these. For this reason, Patent Literature 1 (PTL 1) discloses a technique for extracting ductal structures and microvessels by applying frequency filtering to images obtained by special light observation using narrow-band blue-violet light.

[0003] Patent No. 6017669

[0004] However, the frequency bands corresponding to the ductal structures and the microvessels respectively vary depending on the observation distance, and therefore, the above-mentioned Patent Document 1 has a problem in that it is not possible to appropriately enhance or suppress the microstructures and the microvessels respectively.

[0005] The present disclosure has been made in consideration of the above, and aims to provide an image processing device, a medical system, an operating method of an image processing device, and a program that can appropriately emphasize and suppress each of the fine structures and microvessels in an image regardless of the observation distance.

[0006] In order to solve the above-mentioned problems and achieve the objectives, the image processing device of the present disclosure is an image processing device equipped with a processor, which irradiates illumination light including narrowband blue-violet light toward biological tissue including microstructures and microvessels, acquires an image signal generated by capturing light returned from the biological tissue, extracts local contrast information from the image signal, and, based on the local contrast information, generates a display image by performing one or more of an enhancement process on the image signal that enhances at least one of microstructural information regarding the microstructures in the biological tissue and microvascular information regarding the microvessels, and a suppression process that suppresses at least one of the microstructural information regarding the microstructures in the biological tissue and microvascular information regarding the microvessels.

[0007] In addition, in the image processing device according to the present disclosure, in the above disclosure, the processor extracts a local contrast value as the local contrast information for each pixel constituting an input image corresponding to the image signal, determines for each pixel whether the local contrast value is equal to or greater than at least one predetermined reference value, performs one of the enhancement processing and the suppression processing on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than the reference value, and performs the other of the enhancement processing and the suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value, thereby generating the display image.

[0008] In the image processing device according to the present disclosure, in the above disclosure, the fine structure information corresponds to pixels with large signal values ​​in which the local contrast value is equal to or greater than the reference value.

[0009] In the image processing device according to the present disclosure, in the above disclosure, the microvessel information corresponds to pixels having a signal value in which the local contrast value is not equal to or greater than the reference value.

[0010] In the image processing device according to the present disclosure, the enhancement process is a process of moving the local contrast value away from the reference value, and the processor performs the enhancement process on the fine structure information.

[0011] In the image processing device according to the present disclosure, in the above disclosure, the suppression processing is processing for bringing the local contrast value closer to the reference value, and the processor performs the suppression processing on the microvessel information.

[0012] In addition, in the image processing device according to the present disclosure, the enhancement processing is processing for bringing the local contrast value closer to the reference value, and the processor performs the suppression processing on the fine structure information.

[0013] In the image processing device according to the present disclosure, in the above disclosure, the suppression processing is processing for moving the local contrast value away from the reference value, and the processor performs the enhancement processing on the microvessel information.

[0014] In addition, in the image processing device of the present disclosure, in the above disclosure, the processor extracts the local contrast information based on the relative signal strength ratio between the signal value of a pixel of interest in an input image corresponding to the image signal and the signal values ​​of pixels surrounding the pixel of interest.

[0015] In the image processing device according to the present disclosure, the processor divides the image signal into an illumination light component and a reflectance component, and increases or decreases the signal amplitude value of the reflectance component.

[0016] In addition, the image processing device according to the present disclosure, in the above disclosure, divides the image signal into an illumination light component and a reflectance component, and increases or decreases the signal amplitude value of the illumination light component.

[0017] In addition, in the image processing device according to the present disclosure, in the above disclosure, the processor divides the image signal into an illumination light component and a reflectance component, performs at least one of the enhancement processing and the suppression processing on the signal amplitude value of the reflectance component, and generates the display image by combining the reflectance component that has been subjected to at least one of the enhancement processing and the suppression processing with the illumination light component.

[0018] In addition, in the image processing device according to the present disclosure, in the above disclosure, the processor divides the image signal into an illumination light component and a reflectance component, performs at least one of the enhancement processing and the suppression processing on the reflectance component, performs a gain adjustment processing to adjust the gain of the illumination light component, and generates the display image by combining the illumination light component that has been subjected to the gain adjustment processing and the reflectance component that has been subjected to at least one of the enhancement processing and the suppression processing.

[0019] In addition, in the image processing device according to the present disclosure, in the above disclosure, the processor generates a first illumination light component and a first reflectance component based on the image signal, generates a second reflectance component by combining the first reflectance component and the image signal with a predetermined coefficient, performs at least one of the enhancement processing and the suppression processing on the second reflectance component to generate a third reflectance component, generates a fourth reflectance component based on the third reflectance component and the image signal, and generates the display image by combining the fourth reflectance component and the first reflectance component.

[0020] In addition, in the image processing device of the present disclosure, in the above disclosure, the processor extracts a contrast value, which is a ratio of relative signal strengths, as the local contrast information for each pixel based on the signal value of each pixel of interest included in the image signal and the signal values ​​of each of a plurality of surrounding pixels around the pixel of interest.

[0021] In addition, the medical system according to the present disclosure is a medical system including a light source device, an imaging device, and a medical device, wherein the light source device has a light source that irradiates illumination light including narrowband blue-violet light toward biological tissue including microstructures and microvessels, the imaging device has an imaging element that generates an image signal by capturing light returned from the biological tissue, and the medical device has a processor that acquires the image signal, extracts local contrast information from the image signal, and, based on the local contrast information, generates a display image by performing one or more of an enhancement process on the image signal that emphasizes at least one of microstructural information regarding the microstructure and microvascular information regarding the microvessels in the biological tissue, and a suppression process that suppresses at least one of the microstructural information regarding the microstructure and microvascular information regarding the microvessels in the biological tissue.

[0022] Furthermore, a method for operating an image processing device according to the present disclosure is a method for operating an image processing device that includes a processor, in which the processor irradiates illumination light including narrowband blue-violet light toward biological tissue that includes microstructures and microvessels, acquires an image signal generated by capturing light returned from the biological tissue, extracts local contrast information from the image signal, and, based on the local contrast information, generates a display image by performing one or more of an enhancement process on the image signal that enhances at least one of microstructural information regarding the microstructures and microvascular information regarding the microvessels in the biological tissue, and a suppression process that suppresses at least one of the microstructural information regarding the microstructures and microvascular information regarding the microvessels in the biological tissue.

[0023] In addition, a program according to the present disclosure is a program executed by a medical device that has a processor and is driven according to the cleaning state of a target area, and causes the processor to perform the following steps: irradiate illumination light including narrowband blue-violet light toward biological tissue including microstructures and microvessels, acquire an image signal generated by capturing light returned from the biological tissue, extract local contrast information from the image signal, and, based on the local contrast information, generate a display image by performing one or more of an enhancement process on the image signal that enhances at least one of microstructural information regarding the microstructure in the biological tissue and microvascular information regarding the microvessels, and a suppression process that suppresses at least one of the microstructural information regarding the microstructure in the biological tissue and microvascular information regarding the microvessels.

[0024] According to the present disclosure, it is possible to selectively enhance and suppress fine structures and fine blood vessels in an image, regardless of the observation distance.

[0025] FIG. 1 is a schematic configuration diagram of an endoscopic system according to Embodiment 1. FIG. 2 is a block diagram illustrating the functional configuration of a main part of the endoscopic system according to Embodiment 1. FIG. 3 is a flowchart illustrating an outline of processing performed by the endoscopic system according to Embodiment 1. FIG. 4 is a diagram illustrating a schematic outline of processing performed by the endoscopic system according to Embodiment 1. FIG. 5 is a block diagram illustrating the functional configuration of an endoscopic system according to Embodiment 2. FIG. 6 is a flowchart illustrating an outline of processing performed by the endoscopic system according to Embodiment 2. FIG. 7A is a diagram illustrating a schematic outline of enhancement processing and suppression processing performed by an adjustment unit according to Embodiment 2. FIG. 7B is a diagram illustrating a schematic outline of enhancement processing and suppression processing performed by an adjustment unit according to Modification 1 of Embodiment 2. FIG. 7C is a diagram illustrating a schematic outline of enhancement processing and suppression processing performed by an adjustment unit according to Modification 2 of Embodiment 2. FIG. 7D is a diagram illustrating a table illustrating an example of the relationship between input values ​​and output values ​​based on FIG. 7C in each enhancement mode for each channel constituting an input image. FIG. 7E is a diagram illustrating a schematic outline of enhancement processing and suppression processing performed by an adjustment unit according to Modification 3 of Embodiment 2. FIG. 7F is a diagram showing a table illustrating an example of the relationship between input values ​​and output values ​​based on FIG. 7E at each enhancement level for each channel constituting an input image. FIG. 8 is a diagram schematically illustrating an outline of enhancement processing and suppression processing performed by an adjustment unit according to Embodiment 3. FIG. 9 is a block diagram showing the functional configuration of an endoscopic system according to Embodiment 4. FIG. 10 is a flowchart showing an outline of processing performed by an endoscopic system according to Embodiment 4. FIG. 11 is a diagram schematically illustrating an outline of processing performed by an endoscopic system according to Embodiment 4. FIG. 12 is a diagram schematically illustrating an outline of enhancement processing and suppression processing performed by an adjustment unit according to Embodiment 4. FIG. 13 is a block diagram showing the functional configuration of an endoscopic system according to Embodiment 5. FIG. 14 is a flowchart showing an outline of processing performed by an endoscopic system according to Embodiment 5. FIG. 15 is a diagram schematically illustrating an outline of processing performed by an endoscopic system according to Embodiment 5. FIG. 16 is a diagram schematically illustrating an outline of enhancement processing and suppression processing performed by an adjustment unit according to Embodiment 5.FIG. 17 is a diagram schematically illustrating an overview of the enhancement processing and suppression processing executed by an adjustment unit according to embodiment 5. FIG. 18 is a block diagram illustrating the functional configuration of an endoscopic system according to embodiment 6. FIG. 19 is a diagram illustrating an example of a selection setting screen for selecting an enhancement degree in the VS enhancement mode, which is displayed on a display device by a control unit based on an input from an input unit of the endoscopic system according to embodiment 6. FIG. 20 is a diagram illustrating a parameter table illustrating an example of the relationship between the enhancement degree of the first image processing unit of the endoscopic system according to embodiment 6 and the enhancement level of each enhancement type set in the enhancement processing unit of the second image processing unit that processes each channel constituting an input image. FIG. 21 is a diagram illustrating another parameter table illustrating the relationship between the enhancement degree in each enhancement mode of the first image processing unit of the endoscopic system according to embodiment 6 and each enhancement type and enhancement level set in the enhancement processing unit of the second image processing unit that processes each channel constituting an input image. FIG. 22 is a block diagram illustrating the functional configuration of an endoscopic system according to embodiment 7. FIG. 23 is a diagram illustrating a parameter table illustrating the relationship between the enhancement type set in processing mode 2 and the enhancement mode and enhancement type set in processing mode 1. Fig. 24 is a diagram showing an overview of independent switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1. Fig. 25 is a diagram showing an overview of linked or independent switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1. Fig. 26 is a diagram showing an overview of independent switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1 for each emphasis mode. Fig. 27 is a diagram showing an overview of independent or continuous switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1 for each emphasis mode.

[0026] Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiments. Furthermore, each drawing referred to in the following description merely shows a schematic representation of the shape, size, and positional relationship to the extent that the contents of the present disclosure can be understood. In other words, the present disclosure is not limited to only the shape, size, and positional relationship exemplified in each drawing. Furthermore, in the description of the drawings, identical parts are denoted by the same reference numerals. Furthermore, an endoscopic system equipped with a flexible endoscope will be described as an example of an endoscopic system according to the present disclosure.

[0027] (Embodiment 1) [Configuration of Endoscope System] FIG. 1 is a schematic diagram of an endoscope system according to Embodiment 1. FIG. 2 is a block diagram showing the functional configuration of the main parts of the endoscope system according to Embodiment 1. The endoscope system 1 shown in FIGS. 1 and 2 is inserted into the body of a subject, such as a patient, and displays a display image based on image signals (image data) generated by capturing images of the inside of the subject's body. A user, such as a doctor, observes the displayed image to check for the presence or absence of bleeding sites, tumor sites, and abnormal sites, and to measure their size. Note that in Embodiment 1, an endoscope system using a flexible endoscope as shown in FIG. 1 is described as the endoscope system 1. However, the present invention is not limited to this, and may also be applied to, for example, a medical system equipped with a rigid endoscope. Furthermore, the endoscope system 1 may also be applied to a medical microscope or a medical surgical robot system, which performs surgery, treatment, etc. while displaying a display image based on image signals (image data) captured by the endoscope on a display device.

[0028] The endoscope system 1 shown in FIG. 1 includes an endoscope device 2, a light source device 3, a display device 4, and a control device 5.

[0029] [Configuration of Endoscopic Device] First, we will explain the configuration of the endoscope device 2. The endoscope device 2 is inserted into a subject, captures images of the inside of the subject's body to generate image signals (RAW data), and outputs the generated image signals to the control device 5. The endoscope device 2 includes an insertion section 21, an operation section 22, and a universal cord 23.

[0030] The insertion section 21 has a flexible, elongated shape and includes a distal end portion 24 incorporating an imaging unit 244 (described later), a freely bendable bending section 25 formed of a plurality of bending pieces, and a flexible, elongated flexible tube portion 26 connected to the proximal end side of the bending section 25.

[0031] The tip portion 24 is made of glass fiber, etc. The tip portion 24 has a light guide 241 that forms a light guide path for light supplied from the light source device 3, an illumination lens 242 provided at the tip of the light guide 241, an optical system 243 that collects at least one of reflected light and returned light from the subject, and an imaging unit 244 that is arranged at an imaging position of the optical system 243.

[0032] The illumination lens 242 is configured using one or more lenses, and emits the light supplied from the light guide 241 to the outside.

[0033] The optical system 243 is configured using one or more lenses, and collects return light from the subject and light reflected by the subject to form an image of the subject on the imaging plane of the imaging unit 244. The optical system 243 may be configured to be able to change the focal position (focus position) by moving along the optical axis L1 under the drive of an actuator (not shown). Of course, the optical system 243 may have a zoom lens group whose focal length can be changed by moving multiple lenses along the optical axis L1.

[0034] The imaging unit 244 is configured using an image sensor such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor), and generates an image signal (RAW data) by capturing images at a predetermined frame rate, and outputs this image signal to the control device 5.

[0035] The operation unit 22 has a bending knob 221 for bending the bending portion 25 in the up-down and left-right directions, a treatment tool insertion portion 222 for inserting treatment tools such as biological forceps, a laser scalpel, and an inspection probe into the body cavity, and a plurality of switches 223 for receiving inputs of operation instruction signals for peripheral devices such as an air supply means, a water supply means, and a gas supply means, as well as the light source device 3 and the control device 5, and a pre-freeze signal for instructing the imaging unit 244 to take a still image. The treatment tool inserted from the treatment tool insertion portion 222 passes through a treatment tool channel (not shown) in the distal end portion 24 and emerges from an opening (not shown).

[0036] The universal cord 23 incorporates at least a light guide 241 and a light-collecting cable that is a collection of one or more cables. The collection cable is a signal line for transmitting and receiving signals between the endoscope device 2, the light source device 3, and the control device 5, and includes a signal line (signal data) for transmitting and receiving setting data, a signal line for transmitting and receiving image signals (image data), and a signal line for transmitting and receiving a driving clock signal for driving the imaging unit 244. The universal cord 23 has a connector unit 27 that is detachable from the light source device 3. The connector unit 27 has a coiled coil cable 27a extending therefrom, and a connector unit 28 that is detachable from the control device 5 at the extending end of the coil cable 27a.

[0037] [Configuration of Light Source Device] Next, a description will be given of the configuration of the light source device 3. The light source device 3 supplies illumination light for irradiating the subject from the distal end 24 of the endoscope device 2. The light source device 3 includes a light source unit 31, a light source driver 32, and an illumination control unit 33.

[0038] The light source unit 31 irradiates the subject with at least one of white light including light in the red wavelength band, light in the green wavelength band, and light in the blue wavelength band, and special light. The light source unit 31 has a condenser lens 311, a first light source 312, a second light source 313, a third light source 314, a fourth light source 315, and a fifth light source 316.

[0039] The condenser lens 311 is configured using one or more lenses. The condenser lens 311 condenses the light emitted by each of the first light source 312, the second light source 313, the third light source 314, the fourth light source 315, and the fifth light source 316, and outputs the light to the light guide 241.

[0040] The first light source 312 is configured using a red LED (Light Emitting Diode) lamp. The first light source 312 emits light in the red wavelength band (610 nm to 750 nm) (hereinafter simply referred to as "R light") based on the current supplied from the light source driver 32.

[0041] The second light source 313 is configured using a green LED lamp. The second light source 313 emits light in the green wavelength band (500 nm to 560 nm) (hereinafter simply referred to as “G light”) based on the current supplied from the light source driver 32.

[0042] The third light source 314 is configured using a blue LED lamp. The third light source 314 emits light in the blue wavelength band (435 nm to 480 nm) (hereinafter simply referred to as "B light") based on the current supplied from the light source driver 32.

[0043] The fourth light source 315 is configured using a purple LED lamp. The fourth light source 315 emits narrowband light (hereinafter simply referred to as "V light") in a blue-purple wavelength band (e.g., 400 nm to 435 nm) based on the current supplied from the light source driver 32.

[0044] The fifth light source 316 is configured using a green LED lamp and a transmission filter that transmits a predetermined wavelength band. The fifth light source 316 emits narrowband light of a predetermined wavelength band (530 nm to 550 nm) (hereinafter simply referred to as "NG light") based on the current supplied from the light source driver 32.

[0045] Under the control of the illumination control unit 33, the light source driver 32 supplies current to the first light source 312, the second light source 313, the third light source 314, the fourth light source 315, and the fifth light source 316, causing them to emit light according to the observation mode set in the endoscope system 1. Specifically, under the control of the illumination control unit 33, when the observation mode set in the endoscope system 1 is the normal observation mode, the light source driver 32 causes the first light source 312, the second light source 313, and the third light source 314 to emit light, causing them to emit white light (hereinafter simply referred to as "W light"). Furthermore, under the control of the illumination control unit 33, when the observation mode set in the endoscope system 1 is the special light observation mode, the light source driver 32 causes the fourth light source 315 and the fifth light source 316 to emit light, causing them to emit special light (hereinafter simply referred to as "S light") capable of narrow band imaging (NBI).

[0046] The illumination control unit 33 controls the lighting timing of the light source device 3 based on an instruction signal received from the control device 5. Specifically, the illumination control unit 33 causes the first light source 312, the second light source 313, and the third light source 314 to emit light at a predetermined cycle. The illumination control unit 33 is configured using a CPU (Central Processing Unit) and the like. When the observation mode of the endoscope system 1 is the normal observation mode, the illumination control unit 33 controls the light source driver 32 to cause the first light source 312, the second light source 313, and the third light source 314 to emit light and emit W light. When the observation mode of the endoscope system 1 is the special light observation mode, the illumination control unit 33 controls the light source driver 32 to combine the fourth light source 315 and the fifth light source 316 to emit S light. In addition, the illumination control unit 33 may control the light source driver 32 depending on the observation mode of the endoscopic system 1 to emit light from a combination of two or more of the first light source 312, the second light source 313, the third light source 314, the fourth light source 315, and the fifth light source 316.

[0047] [Configuration of Display Device] Next, a description will be given of the configuration of the display device 4. The display device 4 displays a display image based on image data generated by the endoscope device 2 and received from the control device 5. The display device 4 displays various information related to the endoscope system 1. The display device 4 is configured using a display panel such as a liquid crystal or organic EL (Electro Luminescence) panel.

[0048] [Configuration of Control Device] Next, the configuration of the control device 5 will be described. The control device 5 receives image data generated by the endoscope device 2, performs predetermined image processing on the received image data, and outputs the processed image data to the display device 4. The control device 5 also comprehensively controls the operation of the entire endoscope system 1. The control device 5 includes an image processing unit 51, an input unit 52, a recording unit 53, and a control unit 54.

[0049] The image processing unit 51, under the control of the control unit 54, acquires an image signal generated by the endoscope device 2, performs predetermined image processing on the acquired image signal, and outputs the processed image to the display device 4. The image processing unit 51 is configured using a processor having hardware such as a memory and a GPU (Graphics Processing Unit), a DSP (Digital Signal Processing), or an FPGA (Field Programmable Gate Array). The image processing unit 51 has an acquisition unit 511, a division unit 512, an extraction unit 513, an adjustment unit 514, a synthesis unit 515, and a display control unit 516.

[0050] The acquisition unit 511 acquires an image signal (RAW data) from the imaging unit 244 of the endoscope device 2. Specifically, the acquisition unit 511 acquires an image signal generated by the imaging unit 244 irradiating biological tissue including microstructures and microvessels with illumination light including narrowband blue-violet light and capturing an image of the return light from the biological tissue.

[0051] The dividing unit 512 divides into an illumination light component and a reflectance component the input image corresponding to the image signal acquired by the acquiring unit 511. Specifically, the dividing unit 512 divides the input image corresponding to the image signal into a base image which is an illumination light component that is a low-frequency component, and a detail image which is a reflectance component.

[0052] The extraction unit 513 extracts local contrast information from the image signal acquired by the acquisition unit 511. Specifically, the extraction unit 513 extracts the detail image divided by the division unit 512 as local contrast information of the reflectance component.

[0053] Based on the local contrast information extracted by the extraction unit 513, the adjustment unit 514 performs one or more of an enhancement process that enhances at least one of microstructure information regarding the microstructure in the biological tissue and microvascular information regarding the microvessels, and a suppression process that suppresses at least one of the microstructure information regarding the microstructure in the biological tissue and microvascular information regarding the microvessels, on the image signal acquired by the acquisition unit 511.

[0054] The synthesis unit 515 synthesizes the illumination light component, which is the base image divided by the division unit 512 and has been subjected to gradation compression, with the reflectance component, which is the detail image that has been subjected to enhancement processing by the adjustment unit 514.

[0055] The display control unit 516 generates a display image based on the synthesis result obtained by the synthesis unit 515 and outputs the generated image to the display device 4 .

[0056] The input unit 52 receives input of instruction signals that instruct the operation of the endoscope system 1 and instruction signals that instruct the observation mode of the endoscope system 1, and outputs the received instruction signals to the control unit 54. The input unit 52 is configured using switches, buttons, a touch panel, etc.

[0057] The recording unit 53 records various programs executed by the endoscope system 1, data being executed by the endoscope system 1, and image data generated by the endoscope device 2. The recording unit 53 is configured using a volatile memory, a non-volatile memory, a memory card, etc. The recording unit 53 has a program recording unit 531 that records various programs executed by the endoscope system 1.

[0058] The control unit 54 has a memory and a processor including at least one hardware such as an FPGA or a CPU, etc. The control unit 54 controls each unit constituting the endoscope system 1.

[0059] [Processing of Endoscope System] Next, a description will be given of processing executed by the endoscope system 1. Fig. 3 is a flowchart showing an outline of processing executed by the endoscope system 1. Fig. 4 is a diagram schematically illustrating an outline of processing executed by the endoscope system.

[0060] As shown in FIG. 3, first, the control unit 54 controls the illumination control unit 33 to cause the fourth light source 315 and the fifth light source 316 of the light source device 3 to emit light and irradiate the biological tissue with blue-violet and green narrowband light (step S101).

[0061] Next, the control unit 54 causes the image capturing unit 244 to capture an image of the light returning from the living tissue (step S102), and causes the image capturing unit 244 to generate an image signal (step S103).

[0062] Thereafter, the acquisition unit 511 acquires an image signal (RAW data) from the imaging unit 244 of the endoscope device 2 (step S104).

[0063] Next, the dividing unit 512 divides the input image corresponding to the image signal acquired by the acquiring unit 511 into an illumination light component and a reflectance component (step S105). Specifically, as shown in FIG. 4, the dividing unit 512 divides the input image P ＩＮ１ , whereas the base image P Ｂ１ and the detail image P Ｄ１ In this case, the dividing unit 512 divides the input image P ＩＮ１For example, a well-known bilateral filter is applied to the base image P Ｂ１ The input image P ＩＮ１ In this case, the dividing unit 512 divides the base image P Ｂ１ The dividing unit 512 performs gradation compression on the input image P ＩＮ１ For the input image P ＩＮ１ From the detail image P Ｄ１ For example, the division unit 512 divides the input image P into sub-pixels according to a well-known SSR (Single-Scale Retinex) model in the Retinex model. ＩＮ１ From the detail image P Ｄ１ Here, SSR is a technique that estimates an illumination light component by smoothing a pixel of interest and its surrounding pixels using a Gaussian filter, and calculates a reflectance component from the ratio between the input pixel value of the pixel of interest and the estimated illumination light component. Note that the bilateral filter and SSR are well-known techniques, and detailed explanations thereof will be omitted.

[0064] Next, the extraction unit 513 extracts the detail image divided by the division unit 512 as local contrast information of the reflectance component (step S106). Ｂ１ and the input image P ＩＮ１ In this case, the extraction unit 513 extracts the difference between the base image P Ｂ１ and the input image P ＩＮ１ Based on the signal value of each pixel of interest and the signal values ​​of each of the plurality of surrounding pixels around the pixel of interest, a contrast value, which is a ratio of relative signal strengths, is extracted as contrast information for each pixel, thereby extracting local contrast information.

[0065] Thereafter, the adjustment unit 514 performs enhancement processing on the image signal acquired by the acquisition unit 511, which enhances each of the microstructure information related to the microstructure in the biological tissue and the microvessel information related to the microvessels, based on the local contrast information extracted by the extraction unit 513 (step S107). In this case, the adjustment unit 514 performs enhancement processing on the image signal acquired by the acquisition unit 511, which enhances the detail components, based on the local contrast information extracted by the extraction unit 513. Specifically, as shown in Fig. 4, the adjustment unit 514 performs enhancement processing on the detail image divided by the division unit 512, which enhances the detail components, based on the local contrast information extracted by the extraction unit 513, to generate the detail image P Ｄ２ That is, the adjustment unit 514 performs enhancement processing to increase the signal amplitude value of the reflectance component divided by the division unit 512 based on the local contrast information extracted by the extraction unit 513.

[0066] Thereafter, the combining unit 515 combines the illumination light component, which is the base image divided by the dividing unit 512 and has been subjected to gradation compression, with the reflectance component, which is the detail image that has been subjected to enhancement processing by the adjusting unit 514 (step S108). Specifically, as shown in FIG. 4, the combining unit 515 combines the base image P Ｂ１ And detail image P Ｄ２ and are synthesized.

[0067] Next, the display control unit 516 generates a display image based on the synthesis result generated by the synthesis unit 515 and outputs the generated display image to the display device 4 (step S109). Specifically, as shown in FIG. 4, the display control unit 516 generates a display image P ＯＵＴ１ and this display image P ＯＵＴ１ is output to the display device 4. This allows the user to improve the accuracy of diagnosis by selectively emphasizing the feature amount of the displayed image.

[0068] Next, the control unit 54 determines whether an instruction signal instructing the end of observation of the subject has been input from the input unit 52 (step S110). If the control unit 54 determines that an instruction signal instructing the end of observation of the subject has been input from the input unit 52 (step S110: Yes), the endoscopic system 1 ends this processing. On the other hand, if the control unit 54 determines that an instruction signal instructing the end of observation of the subject has not been input from the input unit 52 (step S110: No), the endoscopic system 1 returns to the above-mentioned step S101.

[0069] According to the first embodiment described above, the combining unit 515 combines the illumination component, which is the base image divided by the dividing unit 512, with the reflectance component, which is the detail image that has been subjected to enhancement processing by the adjusting unit 514, and the display control unit 516 generates a display image based on the combination result obtained by the combining unit 515 and outputs the display image to the display device 4. As a result, it is possible to appropriately enhance and suppress each of the fine structures and microvessels in the image regardless of the observation distance between the distal end 24 of the endoscope device 2 and the biological tissue. This allows the user to easily focus on a desired region (region of interest) because the mucosa and blood vessels of the biological tissue are each enhanced in the display image.

[0070] (Embodiment 2) Next, embodiment 2 will be described. The endoscopic system according to embodiment 2 has a different configuration from the endoscopic system 1 according to embodiment 1 described above, and also performs different processing. Specifically, in embodiment 2, at least one of enhancement processing and suppression processing is performed based on local contrast information for each pixel. Therefore, hereinafter, the functional configuration of the endoscopic system according to embodiment 2 will be described, and then the processing performed by the endoscopic system according to embodiment 2 will be described. Note that the same components as those in the endoscopic system 1 according to embodiment 1 described above will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0071] [Functional Configuration of Endoscope System] Fig. 5 is a block diagram showing the functional configuration of an endoscope system according to embodiment 2. The endoscope system 1A shown in Fig. 5 includes a control device 5A instead of the control device 5 of the endoscope system 1 according to embodiment 1 described above. The control device 5A includes an image processing device 51A instead of the image processing device 51 according to embodiment 1 described above.

[0072] The image processing unit 51A further includes a determination unit 517 in addition to the configuration of the image processing unit 51 according to the first embodiment described above.

[0073] The determination unit 517 determines whether the local contrast value for each pixel is equal to or greater than a predetermined reference value based on the local contrast information extracted by the extraction unit 513, and extracts microstructure information and microvessel information.

[0074] [Processing of Endoscope System] Next, the processing executed by the endoscope system 1A will be described. Fig. 6 is a flowchart showing an outline of the processing executed by the endoscope system 1A. In Fig. 6, steps S201 to S206 are the same as steps S101 to S106 in Fig. 3 described above, and therefore detailed description thereof will be omitted.

[0075] In step S207, the determination unit 517 determines whether the local contrast value for each pixel is equal to or greater than a predetermined reference value, based on the local contrast information extracted by the extraction unit 513, and extracts microstructure information and microvessel information. Note that in the second embodiment, the determination unit 517 makes the determination using one reference value, but is not limited to this, and two separate reference values ​​may be provided for extracting microstructure information and microvessel information, respectively.

[0076] Next, the adjustment unit 514 performs at least one of an enhancement process for enhancing at least one of the microstructure information regarding the microstructure in the biological tissue and the microvascular information regarding the microvessels, and a suppression process for suppressing at least one of the microstructure information regarding the microstructure in the biological tissue and the microvascular information regarding the microvessels, based on the image signal acquired by the acquisition unit 511, the local contrast information extracted by the extraction unit 513, and the determination result of the determination unit 517 (step S208). Specifically, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, the adjustment unit 514 performs an enhancement process by the determination unit 517 on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than a reference value, such that the local contrast values ​​are moved away from the reference value, and a suppression process by the determination unit 517 on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels whose local contrast values ​​are smaller than the reference value), such that the local contrast values ​​are brought closer to the reference value.

[0077] 7A is a diagram schematically illustrating an outline of the enhancement processing and suppression processing executed by the adjustment unit 514. In Fig. 7A, a line L1 indicates the relationship between the input value and the output value of the local contrast value before adjustment, a line L2 indicates the relationship between the input value and the output value of the local contrast value after adjustment when the local contrast value is equal to or greater than a reference value, and a line L3 indicates the relationship between the input value and the output value of the local contrast value after adjustment when the local contrast value is not equal to or greater than the reference value.

[0078] 7A , the adjustment unit 514 performs enhancement processing on the signal values ​​(luminance values) of pixels whose local contrast values ​​are equal to or greater than the reference value by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, to move the local contrast values ​​away from the reference value. That is, the adjustment unit 514 performs enhancement processing on the basis of the local contrast information extracted by the extraction unit 513, to increase the signal amplitude values ​​of the reflectance components divided by the division unit 512.

[0079] 7A , the adjustment unit 514 performs suppression processing to bring the local contrast value closer to the reference value for the signal value (luminance value) of a pixel whose local contrast value is not equal to or greater than the reference value as determined by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513. That is, the adjustment unit 514 performs suppression processing to reduce the signal amplitude value of the illumination light component based on the local contrast information extracted by the extraction unit 513.

[0080] In this way, the adjustment unit 514 can emphasize the fine structure in the biological tissue and suppress the microvessels in the biological tissue.

[0081] Steps S209 to S211 are similar to steps S108 to S111 in FIG. 3, and therefore detailed description thereof will be omitted.

[0082] According to the second embodiment described above, the adjustment unit 514 performs enhancement processing on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than a reference value, by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, in such a way that the local contrast values ​​move away from the reference value. Furthermore, the adjustment unit 514 performs suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels whose local contrast values ​​are smaller than the reference value), by the determination unit 517, in such a way that the local contrast values ​​move closer to the reference value, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513. As a result, it is possible to selectively enhance and suppress each of the mucous membrane and microvessels, which are fine structures in the image, regardless of the observation distance between the tip 24 of the endoscope device 2 and the biological tissue.

[0083] Furthermore, according to the second embodiment, the adjustment unit 514 performs enhancement processing on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than a reference value, by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, in order to move the local contrast values ​​away from the reference value. Furthermore, the adjustment unit 514 performs suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels whose local contrast values ​​are smaller than the reference value), by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, in order to move the local contrast values ​​closer to the reference value. This prevents overexposure of the mucous membrane, which has a fine structure, allowing the user to easily observe the fine structure of the mucous membrane.

[0084] According to the second embodiment, the adjustment unit 514 performs suppression processing to reduce the signal amplitude value of the illumination light component based on the local contrast information extracted by the extraction unit 513. However, the present invention is not limited to this, and for example, emphasis processing may be performed to increase the signal amplitude value of the illumination light component based on the local contrast information extracted by the extraction unit 513.

[0085] (Variation 1 of Embodiment 2) Next, Variation 1 of Embodiment 2 will be described. Variation 1 of Embodiment 2 differs only in the content of the enhancement processing and suppression processing performed by the adjustment unit 514. Therefore, the following will describe the enhancement processing and suppression processing performed by the adjustment unit 514 according to Variation 1 of Embodiment 2. Note that the same components as those in the endoscope system 1A according to the above-described embodiment 2 will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0086] 7B is a diagram schematically illustrating an outline of the enhancement processing and suppression processing executed by adjustment unit 514 according to Variation 1 of Embodiment 2. In Fig. 7B, line L1 indicates the relationship between the input value and the output value of the local contrast value before adjustment, line L2 indicates the relationship between the input value and the output value of the local contrast value after adjustment when the local contrast value is equal to or greater than a reference value, line L3 indicates the relationship between the input value and the output value of the local contrast value after adjustment when the local contrast value is not equal to or greater than the reference value, and line L4 indicates the relationship between the input value and the output value of the local contrast value after adjustment when the local contrast value is equal to or greater than the reference value.

[0087] 7B , the adjustment unit 514 performs enhancement processing on the signal values ​​(luminance values) of pixels whose local contrast values ​​are equal to or greater than a reference value by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, to move the local contrast values ​​away from the reference value. That is, the adjustment unit 514 performs enhancement processing on the signal amplitude values ​​of the reflectance components divided by the division unit 512, based on the local contrast information extracted by the extraction unit 513. Furthermore, under the control of the control unit 54, the adjustment unit 514 performs enhancement processing corresponding to the line L2 or the line L4, based on a selection signal that a user, such as a doctor, uses the input unit 52 to select an enhancement processing mode in accordance with the characteristics of a target disease for a patient.

[0088] According to the first modification of the second embodiment described above, the parameters of the adjustment unit 514 can be changed depending on the characteristics of the target disease, so that an enhanced image according to the target disease can be generated.

[0089] (Second Modification of Second Embodiment) Next, a second modification of the second embodiment will be described. In the second modification of the second embodiment, only the content of the enhancement processing and suppression processing performed by the adjustment unit 514 is different. Specifically, in the second modification of the second embodiment, the content of the enhancement processing and suppression processing performed by the adjustment unit 514 is different, and since different image information is reproduced for each RGB channel input to the image processing unit 51A, the adjustment unit 514 performs the enhancement processing and suppression processing by switching the processing parameters of the enhancement mode (V-enhanced mode, S-enhanced mode, VS-enhanced mode) for the fine structure information and the microvessel information for each RGB channel. For this reason, the following will describe the enhancement processing and suppression processing performed by the adjustment unit 514 according to the second modification of the second embodiment. Note that the same components as those in the endoscope system 1A according to the second embodiment described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0090] FIG. 7C is a diagram schematically illustrating an overview of the enhancement processing and suppression processing performed by the adjustment unit 514 according to Variation 1 of Embodiment 2. FIG. 7D is a diagram illustrating a table showing an example of the relationship between input values ​​and output values ​​based on FIG. 7C for each channel constituting an input image in each enhancement mode. Line L1 indicates the relationship between the input value and output value of the local contrast value before adjustment. Line L2 indicates the relationship between the input value and output value of the local contrast value after adjustment when the local contrast value is equal to or greater than a reference value. Line L3 indicates the relationship between the input value and output value of the local contrast value after adjustment when the local contrast value is less than or equal to the reference value. Line L10 indicates the relationship between the input value and output value of the local contrast value after adjustment when the local contrast value is equal to or greater than a reference value. Line L11 indicates the relationship between the input value and output value of the local contrast value after adjustment when the local contrast value is less than or equal to the reference value. Table T1 shown in FIG. 7D is pre-recorded in the recording unit 53.

[0091] As shown by the lines L1 to L3, L10, and L11 in FIG. 7C and the table T1 in FIG. 7D, under the control of the control unit 54, the adjustment unit 514 performs enhancement processing and suppression processing for each RGB channel in accordance with processing parameters that output output values ​​from input values ​​of local contrast values ​​for each enhancement mode (V enhancement mode, S enhancement mode, VS enhancement mode), based on a selection signal indicating that a user such as a doctor has operated the input unit 52 to select an enhancement mode in accordance with the characteristics of the target disease corresponding to the patient.

[0092] According to the second variant of the second embodiment described above, the parameters of the adjustment unit 514 can be changed according to the characteristics of the target disease, and therefore it is possible to generate an image that has undergone enhancement processing and suppression processing in which the relationship between the input value and the output value of the local contrast value is changed for each RGB channel according to the target disease.

[0093] (Third Modification of Second Embodiment) Next, a third modification of the second embodiment will be described. In the third modification of the second embodiment, only the content of the enhancement processing and suppression processing performed by the adjustment unit 514 is different. Specifically, in the third modification of the second embodiment, the content of the enhancement processing and suppression processing performed by the adjustment unit 514 is different. Since different image information is reproduced for each RGB channel input to the image processing unit 51A, the adjustment unit 514 performs the enhancement processing and suppression processing by switching the processing parameters of the enhancement mode (V-enhanced mode, S-enhanced mode, VS-enhanced mode) for the fine structure information and the microvessel information for each RGB channel. For this reason, the enhancement processing and suppression processing performed by the adjustment unit 514 according to the second modification of the second embodiment will be described below. Note that the same components as those in the endoscope system 1A according to the second embodiment described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0094] Fig. 7E is a diagram schematically illustrating an outline of the enhancement processing and suppression processing executed by the adjustment unit 514 according to Modification 3 of Embodiment 2. Fig. 7F is a diagram illustrating a table illustrating an example of the relationship between the input value and the output value based on Fig. 7E at each enhancement level for each channel constituting the input image.

[0095] Line L1 indicates the relationship between the input and output values ​​of the local contrast value before adjustment. Line L2 indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is equal to or greater than the reference value. Line L3 indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is less than the reference value. Line L8 is a part of line L1 and indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is equal to or greater than the reference value. Line L9 is a part of line L1 and indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is less than the reference value. Line L11 indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is less than the reference value. Line L12 indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is greater than or equal to the reference value. Furthermore, line L13 indicates the relationship between the input and output values ​​of the local contrast value after adjustment when the local contrast value is less than the reference value. Table T2 shown in FIG. 7F is pre-recorded in recording unit 53.

[0096] As shown by the lines L1 to L3, L11 to L13 or L8, L9 in FIG. 7E and the table T2 in FIG. 7F, when a user such as a doctor operates the input unit 52 to execute a selected emphasis mode based on a selection signal selecting an emphasis mode in accordance with the characteristics of a target disease corresponding to a patient, under the control of the control unit 54, and when the emphasis levels within the same emphasis mode differ, the adjustment unit 514 executes emphasis processing and suppression processing by changing and setting the relationship between the input value and the output value of the local contrast value between the R channel and the G channel and the B channel.

[0097] According to the third modification of the second embodiment described above, the parameters of the adjustment unit 514 can be changed in accordance with the characteristics of the target disease. Therefore, even if the degree of enhancement varies within the same enhancement mode, it is possible to generate an image that has undergone enhancement processing and suppression processing in which the relationship between the input value and the output value of the local contrast value is changed for each RGB channel in accordance with the target disease.

[0098] (Embodiment 3) Next, embodiment 3 will be described. The endoscopic system according to embodiment 3 has the same configuration as the endoscopic system 1A according to embodiment 2 described above, but differs in the details of the enhancement processing and suppression processing performed by the adjustment unit 514. Therefore, the enhancement processing and suppression processing performed by the adjustment unit 514 will be described below. Note that the same components as those in the endoscopic system 1A according to embodiment 2 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0099] Fig. 8 is a diagram schematically illustrating an outline of the enhancement processing and suppression processing executed by the adjustment unit 514 according to embodiment 3. In Fig. 8, a line L1 indicates the relationship between the input value and the output value of the local contrast value before adjustment, and a line L4 indicates the relationship between the input value and the output value of the local contrast value after adjustment when the local contrast value is not equal to or greater than the reference value.

[0100] As shown by the lines L1 and L4 in FIG. 8, the adjustment unit 514 adjusts the detail image P Ｄ１ and the detail image P extracted by the extraction unit 513. Ｄ１ Based on the local contrast information of (a) and (b), at least one of enhancement processing for enhancing and suppression processing for suppressing microstructure information related to the microstructure and microvessels related to the microvessels in the biological tissue is performed.

[0101] Specifically, as shown in FIG. 8, the adjustment unit 514 adjusts the detail image P Ｄ１ and the detail image P extracted by the extraction unit 513. Ｄ１ Based on the local contrast information of and , the determination unit 517 performs enhancement processing on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than a reference value, thereby moving the local contrast values ​​away from the reference value, and the determination unit 517 performs suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels whose local contrast values ​​are smaller than the reference value).

[0102] For example, the adjustment unit 514 performs suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels smaller than the reference value) by the determination unit 517 so that the signal values ​​are gradually inclined nonlinearly away from the reference value, and also performs suppression processing so that a certain signal value is output linearly. This allows the user to see that blood vessels are emphasized compared to the mucous membrane, thereby improving the accuracy of diagnosis based on the structure of blood vessels.

[0103] According to the third embodiment described above, the adjustment unit 514 performs enhancement processing on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than a reference value, by the determination unit 517, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513, in such a way that the local contrast values ​​move away from the reference value. Furthermore, the adjustment unit 514 performs suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels whose local contrast values ​​are smaller than the reference value), by the determination unit 517, in such a way that the local contrast values ​​move closer to the reference value, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513. As a result, it is possible to selectively enhance and suppress each of the mucous membrane and microvessels, which are fine structures in the image, regardless of the observation distance between the tip portion 24 of the endoscope device 2 and the biological tissue.

[0104] (Fourth Embodiment) Next, a fourth embodiment will be described. The endoscopic system according to the fourth embodiment differs in configuration from the endoscopic system 1A according to the second embodiment described above in the processing it performs. Specifically, the endoscopic system 1A according to the second embodiment described above uses a base image as is and combines it with a detail image that has been subjected to at least one of enhancement processing and suppression processing, whereas the endoscopic system according to the fourth embodiment performs predetermined image processing on the base image before combining it with a detail image. Therefore, hereinafter, the configuration of the endoscopic system according to the fourth embodiment will be described first, followed by the processing performed by the endoscopic system. Note that the same components as those in the endoscopic system 1A according to the second embodiment described above will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0105] [Functional Configuration of Endoscope System] Fig. 9 is a block diagram showing the functional configuration of an endoscope system according to embodiment 4. The endoscope system 1B shown in Fig. 9 includes a control device 5B instead of the control device 5A of the endoscope system 1A according to embodiment 2 described above. The control device 5B includes an image processing unit 51B instead of the image processing unit 51A according to embodiment 2 described above. The image processing unit 51B includes an adjustment unit 514B instead of the adjustment unit 514 according to embodiment 2 described above.

[0106] The adjustment unit 514B performs at least one of an enhancement process that enhances microstructure information related to the microstructure in the biological tissue and a suppression process that suppresses microvascular information related to the microvascular information, based on the image signal acquired by the acquisition unit 511 and the local contrast information extracted by the extraction unit 513. The adjustment unit 514B also performs a gain adjustment process that adjusts the gain of the base image, which is the illumination light component divided by the division unit 512.

[0107] [Processing of Endoscope System] Fig. 10 is a flowchart showing an outline of the processing executed by the endoscope system 1B. Fig. 11 is a diagram for schematically explaining the outline of the processing executed by the endoscope system 1B. In Fig. 10, steps S301 to S305 are the same as steps S101 to S105 in Fig. 3 described above, and therefore detailed description thereof will be omitted.

[0108] In step S306, the adjustment unit 514B adjusts the base image P Ｂ１ Specifically, as shown in FIG. 11, the adjustment unit 514B performs a gain adjustment process to adjust the gain of the base image P Ｂ１ A gain adjustment process is performed to reduce the gain of the base image P Ｂ２ For example, the adjustment unit 514B generates a base image P Ｂ１ The signal value of each pixel constituting the base image P is multiplied by 0.8. Ｂ２ That is, the adjustment unit 514B performs suppression processing to reduce the signal amplitude value of the illumination light component.

[0109] Steps S307 and S308 are similar to steps S206 and S207 in FIG. 6 described above, and therefore detailed description thereof will be omitted.

[0110] In step S309, the adjustment unit 514B adjusts the detail image P Ｄ１ The determination unit 517 performs enhancement processing on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than the reference value, making the local contrast values ​​move away from the reference value, and the determination unit 517 performs suppression processing on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value, making the local contrast values ​​move closer to the reference value, resulting in a detail image P Ｄ２ After step S309, the endoscope system 1B proceeds to step S310.

[0111] 12 is a diagram showing a schematic overview of the enhancement processing and suppression processing executed by the adjustment unit 514B. In Fig. 10, a straight line L1 indicates the relationship between the input value and the output value of the local contrast value before adjustment, and a broken line L5 indicates the relationship between the input value and the output value of the local contrast value after adjustment.

[0112] As shown by the straight line L1 and the broken line L5 in FIG. 12, the adjustment unit 514B adjusts the detail image P Ｄ１ In contrast, the determination unit 517 performs an enhancement process to suppress halation by moving the local contrast value away from the reference value for the signal values ​​of pixels whose local contrast values ​​are equal to or greater than the reference value by a predetermined value, and by performing an enhancement stronger than that in the second embodiment described above on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than the reference value by a predetermined value. Furthermore, the adjustment unit 514B performs an enhancement process to move the local contrast value away from the reference value in a nonlinear manner so as to have a gentle slope for the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value (pixels smaller than the reference value) by the determination unit 517 in the vicinity of the reference value, thereby obtaining the detail image P Ｄ２In this case, as shown by the broken line L5 in Fig. 12, the adjustment unit 514B performs enhancement processing and suppression processing to enhance the signal value so that the slope of the coefficient multiplied by the signal value is equal to or greater than a reference value. This allows the adjustment unit 514 to enhance the fine structure in the biological tissue and suppress the microvessels in the biological tissue.

[0113] Next, the combining unit 515 combines the base image, on which the adjustment unit 514B has performed the gain adjustment process, with the detail image, on which the adjustment unit 514 has performed at least one of the enhancement process and the suppression process (step S310). Specifically, as shown in FIG. 11 , the combining unit 515 combines the base image P Ｂ２ And detail image P Ｄ２ and are synthesized.

[0114] Thereafter, the display control unit 516 generates a display image based on the synthesis result generated by the synthesis unit 515, and outputs the generated display image to the display device 4 (step S311). Specifically, as shown in FIG. 11 , the display control unit 516 generates a display image P ＯＵＴ２ and this display image P ＯＵＴ２ is output to the display device 4.

[0115] Step S312 is the same process as step S110 in FIG. 3 described above, and therefore a detailed description thereof will be omitted.

[0116] According to the fourth embodiment described above, the adjustment unit 514B adjusts the base image P Ｂ１Furthermore, the adjustment unit 514B performs a gain adjustment process to adjust the gain of the detail image, which is the reflectance components divided by the division unit 512, by performing an enhancement process on the signal values ​​of pixels whose local contrast values ​​are equal to or greater than a reference value using the determination unit 517, thereby moving the local contrast values ​​away from the reference value, and a suppression process on the signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value using the determination unit 517, thereby generating a detail image that has undergone enhancement and suppression processes. Thereafter, the synthesis unit 515 synthesizes the base image that has undergone gain adjustment processing by the adjustment unit 514B and the detail image that has undergone at least one of enhancement and suppression processing by the adjustment unit 514, thereby making it possible to selectively enhance and suppress each of the fine structures and microvessels in the image regardless of the observation distance.

[0117] (Embodiment 5) Next, embodiment 5 will be described. The endoscopic system according to embodiment 5 differs in configuration from the endoscopic system 1A according to embodiment 2 described above, and also differs in the processing it executes. Specifically, the endoscopic system according to embodiment 5 generates and combines two detail images (detail components) for the mucosa and the blood vessels, and then performs at least one of an enhancement process and a suppression process on each of the mucosa and the blood vessels. Therefore, hereinafter, the configuration of the endoscopic system according to embodiment 5 will be described, followed by a description of the processing executed by the endoscopic system. Note that the same components as those in the endoscopic system 1A according to embodiment 2 described above will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0118] [Functional Configuration of Endoscope System] Fig. 13 is a block diagram showing the functional configuration of an endoscope system according to embodiment 5. The endoscope system 1C shown in Fig. 13 includes a control device 5C instead of the control device 5A of the endoscope system 1A according to embodiment 2 described above. The control device 5C includes an image processing unit 51C instead of the image processing unit 51C according to embodiment 1 described above. The image processing unit 51C includes an adjustment unit 514C instead of the adjustment unit 514 according to embodiment 2 described above.

[0119] The adjustment unit 514C generates a first base component by restoring the contrast of the image signal to that of the bright light component divided by the division unit 512, and a second base component by lowering the contrast. Furthermore, the adjustment unit 514C generates a first detail component and a second detail component that are different from each other by combining the first base component and the second base component with the reflectance component divided by the division unit 512. Furthermore, the adjustment unit 514C generates a third detail component by combining the first detail component and the second detail component with a predetermined coefficient, and generates a fourth detail component by performing at least one of an enhancement process and a suppression process on the third detail component.

[0120] [Processing of Endoscope System] Next, the processing executed by the endoscope system 1C will be described. Fig. 14 is a flowchart showing an outline of the processing executed by the endoscope system 1C. Fig. 15 is a diagram schematically explaining an outline of the processing executed by the endoscope system 1C. In Fig. 14, steps S401 to S405 are the same as steps S101 to S105 in Fig. 3 described above, and therefore detailed description thereof will be omitted.

[0121] In step S406, the adjustment unit 514C adjusts the input image P ＩＮ１ Specifically, as shown in FIG. 15 , the adjustment unit 514C generates two illumination light components having different frequency bands based on the input image P ＩＮ１ Based on this, a base image P ＢａｓｅＳｐ and the first detail image P ＤｅｔＳｐ In this case, the adjustment unit 514C generates the input image P ＩＮ１ When the component of is I, the Gaussian is G, and the variance is σVP<σSp, the base image P ＢａｓｅＳｐ The base image P ＢａｓｅＳｐ = G ＶＰ *I ... (1) Here, when the weight of the bilateral filter is Wbi, the base image P ＢａｓｅＳｐcan be expressed by the following equation (2): ＢａｓｅＳｐ =Wbi*I...(2)

[0122] Next, the adjustment unit 514C adjusts the input image P ＩＮ１ and base image P Ｂａｓｅ 15 and 16, the adjustment unit 514C performs alpha blending to generate a second detail image by blending the base image P ＢａｓｅＳｐ and the input image P ＩＮ１ Alpha blending is performed using each of the above to obtain the base image P ＢａｓｅＶｐ２ Specifically, the adjustment unit 514 generates the base image P ＢａｓｅＶｐ２ Generate P ＢａｓｅＶｐ２ = α * P ＩＮ１ + (1-α) * P ＢａｓｅＳｐ ...(3) α can be mixed in a certain ratio.

[0123] Steps S408 and S409 are similar to steps S206 and S207 in FIG. 6, and therefore detailed description thereof will be omitted.

[0124] In step S410, the adjustment unit 514C adjusts the base image P ＢａｓｅＶｐ３ and the input image P ＩＮ１ A detail image P is a composite of the reflectance components ＤｅｔＶｐ and the detail image P generated in step S406. ＤｅｔＳｐ Specifically, as shown in FIG. 14, the adjustment unit 514C performs a synthesis process to synthesize the detail image P ＤｅｔＳｐ and the detail image P generated in step S406. ＤｅｔＳｐ and are combined to form a composite image P ＤｅｔＳｐＶｐ Generate.

[0125] Next, the adjustment unit 514C adjusts the composite image P ＤｅｔＳｐＶｐAt least one of enhancement processing for enhancing microstructure information relating to the microstructure in the biological tissue and suppression processing for suppressing microvascular information relating to the microvascular information is performed on the image data (step S411).

[0126] 17 is a diagram showing a schematic overview of the enhancement processing and suppression processing executed by the adjustment unit 514C. In Fig. 17, a straight line L1 indicates the relationship between the input value and the output value of the local contrast value before adjustment, and a broken line L7 indicates the relationship between the input value and the output value of the local contrast value after adjustment.

[0127] As shown by the broken line L7 in FIG. 17, the adjustment unit 514C determines the detail image P ＤｅｔＳｐＶｐ The signal values ​​of the pixels whose local contrast values ​​are equal to or greater than the reference value are subjected to enhancement processing to move the local contrast values ​​away from the reference value, and the determination unit 517 outputs the detail image P ＤｅｔＳｐＶｐ The detail image P is obtained by performing suppression processing to bring the local contrast value closer to the reference value for the signal values ​​of pixels (pixels smaller than the reference value) whose local contrast value is not equal to or greater than the reference value. ＤｅｔＳｐＶｐ Generate.

[0128] In step S412, the composition unit 515 combines the detail image P generated by the adjustment unit 514C. ＤｅｔＳｐＶｐ and base image P ＢａｓｅＶｐ２ Specifically, as shown in FIG. 15 , the synthesis unit 515 executes synthesis processing to synthesize the detail image P ＤｅｔＳｐＶｐ , base image P ＢａｓｅＶｐ２ The composition unit 515 combines the detail image P generated by the adjustment unit 514C. ＤｅｔＳｐＶｐ and base image P ＢａｓｅＶｐ２ and are synthesized, but the base image P ＢａｓｅＶｐ２ Instead, the input image P ＩＮ１ may be synthesized.

[0129] Thereafter, the display control unit 516 generates a display image based on the synthesis result generated by the synthesis unit 515 and outputs the generated display image to the display device 4 (step S412). Specifically, as shown in FIG. 15 , the display control unit 516 generates a display image PＯＵＴ３ and this display image P ＯＵＴ３ is output to the display device 4.

[0130] Step S414 is the same process as step S110 in FIG. 3 described above, and therefore a detailed description thereof will be omitted.

[0131] According to the fifth embodiment described above, it is possible to appropriately enhance each of the fine structures and the fine blood vessels in the image regardless of the observation distance.

[0132] (Embodiment 6) Next, embodiment 6 will be described. The endoscopic system according to embodiment 6 has a different configuration from the endoscopic system 1A according to embodiment 2 described above, and also differs in the processing that it executes. Therefore, hereinafter, the functional configuration of the endoscopic system according to embodiment 6 will be described, and then the processing that the endoscopic system according to embodiment 6 executes will be described. Note that the same components as those in the endoscopic system 1A according to embodiment 2 described above will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0133] [Functional Configuration of Endoscope System] Fig. 18 is a block diagram showing the functional configuration of an endoscope system according to embodiment 6. The endoscope system 1D shown in Fig. 18 includes a control device 5D instead of the control device 5A of the endoscope system 1A according to embodiment 2 described above. The control device 5D includes a first image processing device 51D instead of the image processing device 51A according to embodiment 2 described above. Furthermore, the control device 5D further includes a second image processing device 55.

[0134] The first image processing unit 51D has the same functions as the image processing unit 51A according to the second embodiment described above, and includes an acquisition unit 511, a division unit 512, an extraction unit 513, an adjustment unit 514, a synthesis unit 515, a display control unit 516, and a judgment unit 517.

[0135] The second image processing unit 55 has an enhancement processing unit 551 that performs multiple sharpness enhancement processes (e.g., spatial filter processing, etc.) with different enhancement characteristics to enhance sharpness and color enhancement processes (e.g., IHb color enhancement to highlight slight color changes in the mucous membrane) on the image signal that has been image processed by the first image processing unit 51D, and a display control unit 552 that generates a display image based on the image signal that has been image processed by the enhancement processing unit 551 and outputs the image to the display device 4.

[0136] In the endoscope system 1D configured as described above, the control unit 54 reads and changes the processing parameters of the first image processing unit 51D and the second image processing unit 55 from the record data recorded by the recording unit 53, in accordance with the enhancement degree in the enhancement mode (V enhancement mode, S enhancement mode, VS enhancement mode) of the first image processing unit 51D and the enhancement level in the enhancement type (sharpness enhancement Type A, Type B, color enhancement Type C) of the second image processing unit 55, based on an input from the input unit 52. Note that the processing parameters of the enhancement modes are similar to those in Modification 3 of the second embodiment described above, and therefore detailed description thereof will be omitted (see FIGS. 7E and 7F ).

[0137] Fig. 19 is a diagram showing an example of a selection setting screen for selecting the emphasis degree of the VS emphasis mode, which is displayed on the display device 4 by the control unit 54 based on an input from the input unit 52. Fig. 20 is a diagram showing a parameter table showing an example of the relationship between the emphasis degree of the first image processing unit 51D and the emphasis level of each emphasis type set by the emphasis processing unit 551 of the second image processing unit 55, which is processed for each channel constituting the input image.

[0138] 19 , a user such as a doctor operates the input unit 52 to select a desired emphasis level from among a strong icon U10, a medium icon U11, and a weak icon U12, which indicate the emphasis level for the VS emphasis mode, on a selection setting screen U1 that the control unit 54 and the display control unit 551 display on the display device based on the input from the input unit 52. In response to this operation, the control unit 54 reads and changes the processing parameters (see the parameter table T10 in FIG. 20 ) of the first image processing unit 51D and the second image processing unit 55 from the recorded data recorded by the recording unit 53, depending on the emphasis level in each emphasis mode (V emphasis mode, S emphasis mode, VS emphasis mode) of the first image processing unit 51D and the emphasis level in each emphasis type by the second image processing unit 55. That is, the control unit 54 switches the emphasis level of the second image processing unit 55 in conjunction with the emphasis level of the first image processing unit 51D.

[0139] According to the sixth embodiment described above, by switching between a plurality of different emphasis degrees, it is possible to perform observation and diagnosis with an emphasis effect that is appropriate for the user.

[0140] In the sixth embodiment, FIG. 19 illustrates the VS emphasis mode as an example. However, similarly, for the V emphasis mode and the S emphasis mode, a selection setting screen for selecting the emphasis degree for the V emphasis mode or the S emphasis mode may be displayed, and based on the selected emphasis degree, the parameter table T10 may be referenced to read and change the processing parameters, thereby switching between a plurality of emphasis degrees with different degrees of emphasis.

[0141] In addition, in embodiment 6, the emphasis level of the emphasis type by the second image processing unit 55 was linked to the emphasis degree in each emphasis mode (V emphasis mode, S emphasis mode, VS emphasis mode) of the first image processing unit 51D, but it is also possible to switch at least one of the emphasis type and the emphasis level in a linked manner.

[0142] Figure 21 is a diagram showing another parameter table showing the relationship between the emphasis degree in each emphasis mode of the first image processing unit 51D and each emphasis type and emphasis level set in the emphasis processing unit 551 of the second image processing unit 55 that processes each channel that makes up the input image.

[0143] As shown in the parameter table T11 of Fig. 21 , the control unit 54 reads out and changes the processing parameters (see the parameter table T11 of Fig. 21 ) of the first image processing unit 51D and the second image processing unit 55 from the recorded data recorded by the recording unit 53, in accordance with the emphasis degree in each emphasis mode of the first image processing unit 51D and each emphasis type (sharpness emphasis Type A, Type B, color emphasis processing Type C) and the emphasis level for each emphasis type by the second image processing unit 55. That is, the control unit 54 switches the emphasis type and emphasis level of the second image processing unit 55 in conjunction with the emphasis degree of the first image processing unit 51D. In this way, by switching between a plurality of emphasis degrees with different degrees of emphasis, it is possible to perform observation and diagnosis with an emphasis effect that is appropriate for the user.

[0144] (Seventh Embodiment) Next, a seventh embodiment will be described. The endoscope system according to the seventh embodiment has a different configuration from the endoscope system 1D according to the sixth embodiment described above, and also differs in the processing that it executes. Therefore, hereinafter, the functional configuration of the endoscope system according to the seventh embodiment will be described, and then the processing that the endoscope system according to the seventh embodiment executes will be described. Note that the same components as those in the endoscope system 1D according to the sixth embodiment described above will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0145] [Functional Configuration of Endoscope System] Fig. 22 is a block diagram showing the functional configuration of an endoscope system according to embodiment 7. The endoscope system 1E shown in Fig. 22 includes a control device 5E instead of the control device 5D of the endoscope system 1D according to embodiment 6 described above. The control device 5E further includes a switching unit 56 in addition to the functional configuration of the control device 5D according to embodiment 6 described above.

[0146] Under the control of the control unit 54, the switching unit 56 outputs the image signal input from the endoscope device 2 to either the first image processing unit 51D or the second image processing unit 55. Specifically, under the control of the control unit 54, when the user operates the input unit 52 and selects processing mode 1, the switching unit 56 inputs the image signal input from the endoscope device 2 to the first image processing unit 51D, and when the user operates the input unit 52 and selects processing mode 2, the switching unit 56 inputs the image signal input from the endoscope device 2 to the second image processing unit 55.

[0147] In the endoscope system 1E configured as described above, the user operates the input unit 52 to select processing mode 1 or processing mode 2 under the control of the control unit 54. When selecting processing mode 1, an emphasis mode (V-emphasis mode, S-emphasis mode, VS-emphasis mode) is selected, and when selecting processing mode 2, an emphasis type (Type A, Type B, Type C) in the second image processing unit 55 is selected. Furthermore, processing parameters of the first image processing unit 51D and the second image processing unit 55 when switching between the processing modes (processing mode 1 and processing mode 2) by the endoscope system 1E will be described. FIG. 23 is a parameter table showing the relationship between the emphasis type set in processing mode 2 and the emphasis mode and emphasis type set in processing mode 1. Note that each emphasis mode refers to any of the V-emphasis mode, S-emphasis mode, and VS-emphasis mode.

[0148] As shown in the parameter table T20 of FIG. 23 , when the user operates the input unit 52 to select processing mode 2 and set the emphasis type to Type A or Type B, and then select processing mode 1 and any of the emphasis modes, the control unit 54 reads and changes the processing parameters (see the parameter table T20 of FIG. 23 ) of the first image processing unit 51D and the second image processing unit 55 from the data recorded by the recording unit 53. Here, Types A and B are sharpness enhancement processes with different characteristics. In this way, the control unit 54 sets the emphasis type of the second image processing unit 55 in processing mode 1 in conjunction with the setting of the emphasis type of the second image processing unit 55 in processing mode 2. This allows switching between multiple emphasis modes with different degrees of emphasis processing and suppression processing while interlocking the emphasis types, enabling observation and diagnosis with an emphasis effect appropriate for the user.

[0149] The emphasis type in processing mode 1 may be set independently of the emphasis type in processing mode 2. Fig. 24 is a diagram showing an overview of switching independently between the emphasis type in processing mode 2 and the emphasis type in processing mode 1.

[0150] As shown in FIG. 24, when the user operates the input unit 52 to select either Independent (Select Type A) or Independent (Select Type B) on the setting menu screen U21 and select one of the emphasis modes in processing mode 1, the control unit 54 selects either Type A or Type B for all emphasis modes and sets the processing parameters of Type A or Type B (see table T21 in FIG. 24) in the emphasis processing unit 551 of the second image processing unit 55.

[0151] Furthermore, the emphasis type to be combined with each emphasis mode of processing mode 1 can be selected in conjunction with or independently of the emphasis type selected in processing mode 2.

[0152] FIG. 25 is a diagram showing an outline of switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1 in conjunction with or independently of each other.

[0153] As shown in FIG. 25, when the user operates the input unit 52 to select either linked, independent (Type A selected), or independent (Type B selected) on the setting menu screen U22 and select either processing mode 1 or emphasis mode, the control unit 54 selects either emphasis Type A or Type B, in which all emphasis modes are set when processing mode 2 is selected, according to the selected content, and sets the processing parameters of Type A or Type B in the emphasis processing unit 551 of the second image processing unit 55.

[0154] Furthermore, the user can set a combination of emphasis types for each emphasis mode in processing mode 1 independently of the emphasis type set in processing mode 2.

[0155] FIG. 26 is a diagram showing an outline of switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1 by selecting the emphasis type independently for each emphasis mode.

[0156] As shown in Figure 26, when the user operates the input unit 52 and selects either Independent (Select Type A) or Independent (Select Type B) as the emphasis type for each emphasis mode of processing mode 1 on the setting menu screen U23, the control unit 54 selects Type A or Type B for each emphasis mode according to the selected content, and sets the processing parameters of Type A or Type B in the emphasis processing unit 551 of the second image processing unit 55.

[0157] In addition, the user can select whether the emphasis type combined with each emphasis mode in processing mode 1 is linked to the emphasis type selected in processing mode 2 or is independent.

[0158] FIG. 27 is a diagram showing an outline of switching between the emphasis type in processing mode 2 and the emphasis type in processing mode 1 by selecting the emphasis type independently or consecutively for each emphasis mode.

[0159] As shown in Figure 27, when the user operates the input unit 52 and selects either linked, independent (selects Type A), or independent (selects Type B) as the emphasis type for each emphasis mode of processing mode 1 on the setting menu screen U24, the control unit 54, depending on the selected content, selects each emphasis mode in linkage with the emphasis type set when processing mode 2 was selected, or selects Type A and Type B independently, and sets the processing parameters of Type A or Type B in the emphasis processing unit 551 of the second image processing unit 55.

[0160] Although the above description has been given using Type A and Type B as examples, a parameter table may also be provided that adds color enhancement processing Type C to the options.Furthermore, a parameter table may also be provided that adds an enhancement type that combines sharpness enhancement and color enhancement to the options.

[0161] According to the seventh embodiment described above, observation and diagnosis can be performed with an emphasis effect that is appropriate for the user.

[0162] (Other Embodiments) Various inventions can be formed by appropriately combining multiple components disclosed in the endoscopic systems according to the above-mentioned first to fifth embodiments of the present disclosure. For example, some components may be omitted from all the components described in the endoscopic systems according to the above-mentioned embodiments of the present disclosure. Furthermore, the components described in the endoscopic systems according to the above-mentioned embodiments of the present disclosure may be appropriately combined.

[0163] Furthermore, in the endoscope systems according to the first to fifth embodiments of the present disclosure, the components are connected to each other by wire, but they may be connected wirelessly via a network.

[0164] Furthermore, in the first to fifth embodiments of the present disclosure, the functions of the image processing units 51, 51A, 51B, and 51C included in the endoscope system, such as the functional modules of the acquisition unit 511, the division unit 512, the extraction unit 513, the adjustment units 514, 514A, 514B, and 514C, the synthesis unit 515, the display control unit 516, and the determination unit 517, may be provided in a server connectable via a network or an image processing device capable of bidirectional communication with the endoscope system. Of course, each functional module may be provided in its own server or image processing device.

[0165] Furthermore, in the first to fifth embodiments of the present disclosure, an observation mode corresponding to each of the first to fifth embodiments described above may be provided. In this case, according to the first to fifth embodiments of the present disclosure, the observation mode corresponding to each of the first to fifth embodiments described above may be switched to in response to an operation signal from the input unit 52 or an operation signal from the plurality of switches 223. This allows the user to observe the mucosa and blood vessels of biological tissue in a state in which desired microstructures and microvessels are selectively emphasized and suppressed, respectively.

[0166] Furthermore, in the endoscope systems according to the first to fifth embodiments of the present disclosure, the above-described "unit" can be read as "means," "circuit," etc. For example, a control unit can be read as control means or a control circuit.

[0167] In the explanation of the flowcharts in this specification, the order of processing between steps is clearly indicated using expressions such as "first," "then," and "continue," but the order of processing required to implement the present invention is not uniquely determined by these expressions. In other words, the order of processing in the flowcharts described in this specification can be changed within a consistent range.

[0168] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that include the embodiments described in the present disclosure section and that have undergone various modifications and improvements based on the knowledge of those skilled in the art.

[0169] 1, 1A, 1B, 1C, 1D, 1E Endoscope system 2 Endoscope device 3 Light source device 4 Display device 5, 5A, 5B, 5C, 5D, 5E Control device 21 Insertion section 31 Light source section 32 Light source driver 33 Illumination control section 51, 51A, 51B, 51C Image processing section 51D First image processing section 52 Input section 53 Recording section 54 Control section 55 Second image processing section 56 Switching section 241 Light guide 242 Illumination lens 243 Optical system 244 Imaging section 311 Condenser lens 312 First light source 313 Second light source 314 Third light source 315 Fourth light source 316 Fifth light source 511 Acquisition section 512 Division section 513 Extraction section 514, 514A, 514B, 514C Adjustment unit 515 Combination unit 516, 552 Display control unit 517 Determination unit 531 Program recording unit 551 Emphasis processing unit

Claims

1. An image processing device including a processor, The processor: Irradiating biological tissue including microstructures and microvessels with illumination light including blue-violet narrowband light, and capturing an image of the return light from the biological tissue to generate an image signal; extracting local contrast information in the image signal; generating a display image by performing, on the image signal based on the local contrast information, one or more of an enhancement process for enhancing at least one of microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels, and a suppression process for suppressing at least one of the microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels; Image processing device.

2. 2. The image processing device according to claim 1, The processor: extracting a local contrast value as the local contrast information for each pixel constituting an input image corresponding to the image signal; determining, for each pixel, whether the local contrast value is equal to or greater than at least one preset reference value; performing one of the enhancement processing and the suppression processing on signal values ​​of pixels whose local contrast values ​​are equal to or greater than the reference value, and performing the other of the enhancement processing and the suppression processing on signal values ​​of pixels whose local contrast values ​​are not equal to or greater than the reference value, to generate the display image. Image processing device.

3. 3. The image processing device according to claim 2, The microstructure information is the local contrast value corresponds to a pixel with a large signal value equal to or greater than the reference value, Image processing device.

4. 3. The image processing device according to claim 2, The microvascular information is the local contrast value corresponds to a pixel with a signal value that is not equal to or greater than the reference value, Image processing device.

5. 4. The image processing device according to claim 3, The enhancement process includes: a process of moving the local contrast value away from the reference value, The processor: performing the enhancement processing on the fine structure information; Image processing device.

6. 5. The image processing device according to claim 4, The suppression process is a process of bringing the local contrast value closer to the reference value, The processor: performing the suppression processing on the microvessel information; Image processing device.

7. 4. The image processing device according to claim 3, The suppression process is a process of bringing the local contrast value closer to the reference value, The processor: performing the suppression processing on the microstructure information; Image processing device.

8. 8. The image processing device according to claim 7, The enhancement process includes: a process of moving the local contrast value away from the reference value, The processor: performing the enhancement processing on the microvessel information; Image processing device.

9. 2. The image processing device according to claim 1, The processor: extracting the local contrast information based on a relative signal intensity ratio between a signal value of a pixel of interest in an input image corresponding to the image signal and signal values ​​of pixels surrounding the pixel of interest; Image processing device.

10. 2. The image processing device according to claim 1, The processor: Dividing the image signal into an illumination light component and a reflectance component; Increasing or decreasing the signal amplitude value of the reflectance component; Image processing device.

11. 2. The image processing device according to claim 1, The processor: Dividing the image signal into an illumination light component and a reflectance component; Increasing or decreasing the signal amplitude value of the illumination light component; Image processing device.

12. 2. The image processing device according to claim 1, The processor: Dividing the image signal into an illumination light component and a reflectance component; performing at least one of the enhancement processing and the suppression processing on the signal amplitude value of the reflectance component; generating the display image by combining the reflectance component that has been subjected to at least one of the enhancement processing and the suppression processing with the illumination light component; Image processing device.

13. 2. The image processing device according to claim 1, The processor: Dividing the image signal into an illumination light component and a reflectance component; performing at least one of the enhancement processing and the suppression processing on the reflectance component; performing a gain adjustment process for adjusting the gain of the illumination light component; generating the display image by combining the illumination light component that has been subjected to the gain adjustment processing and the reflectance component that has been subjected to at least one of the enhancement processing and the suppression processing; Image processing device.

14. 2. The image processing device according to claim 1, The processor: generating two illumination light components having different frequency bands based on the image signal; generating two reflectance components based on the two illumination light components and the image signal; The two reflectance components are combined using a predetermined coefficient; performing at least one of the enhancement processing and the suppression processing on a synthesis result obtained by synthesizing the two reflectance components using a predetermined coefficient; generating the display image by combining a result of at least one of the enhancement processing and the suppression processing with one of the two illumination light components; Image processing device.

15. 2. The image processing device according to claim 1, The processor: extracting a contrast value, which is a relative signal strength ratio, for each pixel as the local contrast information based on a signal value of each pixel of interest included in the image signal and each signal value of a plurality of pixels surrounding the pixel of interest; Image processing device.

16. The image processing device according to claim 1, The processor: determining whether or not the local contrast value is equal to or greater than a reference value for each pixel based on the local contrast information, and extracting microstructure information and microvessel information; Image processing device.

17. The image processing device according to claim 1, The processor: extracting, based on the local contrast information, pixels whose local contrast values ​​are greater than a reference value as fine structure information, and extracting, based on the local contrast information, pixels whose local contrast values ​​are smaller than the reference value as microvessel information; Image processing device.

18. The image processing device according to claim 1, The processor: determining whether or not a local contrast value is equal to or greater than a first reference value for each pixel based on the local contrast information, and extracting fine structure information; Image processing device.

19. The image processing device according to claim 1, The processor: extracting, based on the local contrast information, pixels whose local contrast values ​​are greater than at least a first reference value as fine structure information; Image processing device.

20. The image processing device according to claim 1, The processor: determining whether or not the local contrast value is equal to or less than a second reference value for each pixel based on the local contrast information, and extracting microvessel information; Image processing device.

21. The image processing device according to claim 1, The processor: extracting, as microvessel information, pixels whose local contrast values ​​are smaller than at least a second reference value based on the local contrast information; Image processing device.

22. The image processing device according to claim 1, The processor: Highlighting modes are selectable, Image processing device.

23. The image processing device according to claim 22, The emphasis mode is a first enhancement mode that enhances microvessels; a second enhancement mode that enhances fine structures; a third enhancement mode that enhances microvessels and microstructures; Including, Image processing device.

24. The image processing device according to claim 23, The processor: When the first enhancement mode is set as the enhancement mode, at least microvessel information is extracted based on the local contrast information, and enhancement processing is applied to the microvessel information. Image processing device.

25. The image processing device according to claim 23, The processor: when the second emphasis mode is set as the emphasis mode, at least fine structure information is extracted based on the local contrast information, and emphasis processing is applied to the fine structure information. Image processing device.

26. The image processing device according to claim 23, The processor: when the third enhancement mode is set as the enhancement mode, extracting microvessel information and microstructure information based on the local contrast information, and applying enhancement processing to the microvessel information and the microstructure information. Image processing device.

27. The image processing device according to claim 1, further comprising a memory for recording a correspondence relationship between an input value before application of an enhancement process for a local contrast value and an output value after application of the enhancement process; Image processing device.

28. The image processing device according to claim 1, further comprising a memory for recording a correspondence relationship between an input value before application of a suppression process for a local contrast value and an output value after application of the suppression process; Image processing device.

29. The image processing device according to claim 1, a memory for recording a correspondence relationship between an input value before applying an enhancement process to a local contrast value related to microvessel information and an output value after applying the enhancement process; Image processing device.

30. The image processing device according to claim 1, a memory for recording a correspondence relationship between an input value before applying an enhancement process to a local contrast value related to fine structure information and an output value after applying the enhancement process; Image processing device.

31. The image processing device according to claim 1, The processor: The emphasis level can be selected, Image processing device.

32. The image processing device according to claim 31, The emphasis levels include a first emphasis level and a second emphasis level. Image processing device.

33. The image processing device according to claim 32, The first enhancement level is: An enhancement process stronger than the second enhancement level is applied. Image processing device.

34. The image processing device according to claim 33, the enhancement process is a process of moving a local contrast value away from a reference value, The first enhancement level is: The value that moves the value away from the reference value is larger than that of the second emphasis level. Image processing device.

35. A medical system including a light source device, an imaging device, and a medical device, The light source device is a light source that irradiates illumination light including blue-violet narrowband light toward biological tissue including microstructures and microvessels; The imaging device is an imaging element that generates an image signal by capturing an image of the return light from the biological tissue; The medical device comprises: a processor; acquiring the image signal; extracting local contrast information in the image signal; generating a display image by performing, on the image signal based on the local contrast information, one or more of an enhancement process for enhancing at least one of microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels, and a suppression process for suppressing at least one of the microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels; Medical systems.

36. 1. A method of operating an image processing device having a processor, comprising: the processor: controlling the light source to emit at least blue-violet light, and acquiring an image signal generated by capturing an image of return light from the biological tissue when the blue-violet light is emitted; extracting local contrast information in the image signal; generating a display image by performing, on the image signal based on the local contrast information, one or more of an enhancement process for enhancing at least one of microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels, and a suppression process for suppressing at least one of the microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels; A method for operating an image processing device.

37. A program executed by a processor of an image processing device, comprising: the processor, Irradiating biological tissue including microstructures and microvessels with illumination light including blue-violet narrowband light, and capturing an image of the return light from the biological tissue to generate an image signal; extracting local contrast information in the image signal; generating a display image by performing, on the image signal based on the local contrast information, one or more of an enhancement process for enhancing at least one of microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels, and a suppression process for suppressing at least one of the microstructure information related to the microstructure in the biological tissue and microvascular information related to microvessels; To make it happen, program.