Medical system, image selection method, and image selection program

Abstract

A medical system (1) comprises: a first image processing device (3) that executes first image processing on a captured image captured by an imaging device (2); and a second image processing device (4) that executes second image processing on the captured image on which the first image processing has been executed. The first image processing device (3) comprises: an evaluation unit that calculates an evaluation value for each of a plurality of captured images for selecting a freeze image to be displayed on a display device (5) from among chronologically successive captured images; and an image selection unit that acquires the evaluation values of the plurality of captured images, and selects a freeze image from among the plurality of captured images on the basis of the evaluation values.

Description

Medical system, image selection method, and image selection program

[0001] The present invention relates to a medical system, an image selection method, and an image selection program.

[0002] Conventionally, an endoscopic system for observing the inside of a subject using an endoscope has been known (see, for example, Patent Document 1). The endoscopic system described in Patent Document 1 includes a processing device communicatively connected to the endoscope and to a display device. The processing device performs various image processing on an image captured by the endoscope and generates an endoscopic image to be displayed on the display device.

[0003] However, in the processing device described in Patent Document 1, a processing unit in a single housing is configured to perform various types of image processing, so when updating only the configuration that performs some of the various types of image processing, it is necessary to update the entire processing device.

[0004] Here, a possible configuration in which only a portion of the image processing can be updated is a configuration in which a first image processing device performs a portion of the various image processing, and a second image processing device performs the remaining image processing of the various image processing, i.e., dividing the processing device into two devices.

[0005] Furthermore, conventional endoscope systems have a function known as pre-freeze, which selects the image with the best image quality (hereinafter referred to as a freeze image) from a plurality of chronologically consecutive captured images taken within a certain period of time prior to the moment a switch was operated (freeze command) by the user. This pre-freeze function uses an evaluation unit that calculates evaluation values ​​for each of the plurality of captured images, such as the degree of blur, color shift, halation, and blur, and an image selection unit that selects a freeze image from the plurality of captured images based on the evaluation values.

[0006] Patent No. 6378846

[0007] Furthermore, if the pre-freeze function is configured to be executable in a configuration in which the processing device is divided into two devices, a first and a second image processing device, as described above, the following problem may occur. For example, consider a case in which the above-described image selection unit is provided in the first image processing device, which is communicatively connected to the endoscope, and the above-described evaluation unit is provided in the second image processing device, which is communicatively connected to the display device. In this case, the evaluation value calculated by the evaluation unit needs to be transmitted from the second image processing device to the first image processing device, countering the flow of captured images (the flow from the first image processing device to the second image processing device). This can result in a time lag between the freeze instruction being issued and the display of the frozen image. Therefore, there is a demand for a technology that can eliminate the time lag between the freeze instruction being issued and the display of the frozen image, thereby improving convenience.

[0008] The present invention has been made in view of the above, and an object of the present invention is to provide a medical system, an image selection method, and an image selection program that can improve convenience.

[0009] In order to solve the above-mentioned problems and achieve the object, the medical system of the present invention comprises a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, and the first image processing device comprises an evaluation unit that calculates an evaluation value for each of the plurality of captured images in chronological order to select a freeze image to be displayed on a display device from among the plurality of captured images, and an image selection unit that acquires the evaluation value for each of the plurality of captured images and selects the freeze image from among the plurality of captured images based on the evaluation value.

[0010] Furthermore, the medical system according to the present invention comprises a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, wherein the first image processing device comprises a first evaluation unit that calculates a first evaluation value for each of the plurality of captured images in order to select a freeze image to be displayed on a display device from among the plurality of chronologically consecutive captured images, and the second image processing device comprises a second evaluation unit that calculates a second evaluation value for each of the plurality of captured images in order to select the freeze image from among the plurality of captured images, and an image selection unit that acquires the first evaluation value and the second evaluation value for each of the plurality of captured images and selects the freeze image from among the plurality of captured images based on the first evaluation value and the second evaluation value.

[0011] Furthermore, the medical system according to the present invention comprises a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, and the second image processing device comprises an evaluation unit that calculates an evaluation value for each of the plurality of captured images in order to select a freeze image to be displayed on a display device from among the plurality of chronologically consecutive captured images, and an image selection unit that acquires the evaluation value for each of the plurality of captured images and selects the freeze image from among the plurality of captured images based on the evaluation value.

[0012] Furthermore, the image selection method of the present invention is an image selection method executed by a medical system, the medical system including a first image processing device that performs first image processing on captured images captured by an imaging device, and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, and in the image selection method, the first image processing device calculates an evaluation value for each of the captured images in chronological order to select a freeze image to be displayed on a display device from among the captured images, and selects the freeze image from among the captured images based on the evaluation value for each of the captured images.

[0013] Furthermore, an image selection method according to the present invention is an image selection method executed by a medical system, the medical system comprising a first image processing device that performs first image processing on captured images captured by an imaging device, and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, and in the image selection method, the first image processing device calculates a first evaluation value for each of the captured images that are chronologically consecutive, in order to select a freeze image to be displayed on a display device from the captured images, and the second image processing device calculates a second evaluation value for each of the captured images in order to select the freeze image from the captured images, and selects the freeze image from the captured images based on the first evaluation value and the second evaluation value for each of the captured images.

[0014] Furthermore, the image selection method of the present invention is an image selection method executed by a medical system, the medical system including a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, and in the image selection method, the second image processing device calculates an evaluation value for each of the plurality of captured images that are chronologically consecutive, in order to select a freeze image to be displayed on a display device from the plurality of captured images, and selects the freeze image from the plurality of captured images based on the evaluation value for each of the plurality of captured images.

[0015] Furthermore, the image selection program of the present invention is an image selection program executed by a medical system, the medical system comprising a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, and the image selection program causes the medical system to execute a step in which the first image processing device calculates an evaluation value for each of the plurality of captured images to select a freeze image to be displayed on a display device from among the plurality of chronologically consecutive captured images, and selects the freeze image from among the plurality of captured images based on the evaluation value for each of the plurality of captured images.

[0016] Moreover, the image selection program of the present invention is an image selection program executed by a medical system, the medical system including a first image processing device that performs first image processing on captured images captured by an imaging device, and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, and the image selection program causes the medical system to execute the following steps: a step in which the first image processing device calculates a first evaluation value for each of the captured images in chronological order to select a freeze image to be displayed on a display device from the captured images; and a step in which the second image processing device calculates a second evaluation value for each of the captured images in order to select the freeze image from the captured images, and selects the freeze image from the captured images based on the first evaluation value and the second evaluation value for each of the captured images.

[0017] Furthermore, the image selection program of the present invention is an image selection program executed by a medical system, the medical system comprising a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, and the image selection program causes the medical system to execute a step in which the second image processing device calculates an evaluation value for each of the plurality of captured images in chronological order to select a freeze image to be displayed on a display device from among the plurality of captured images, and selects the freeze image from among the plurality of captured images based on the evaluation value for each of the plurality of captured images.

[0018] The medical system, image selection method, and image selection program according to the present invention can improve convenience.

[0019] Fig. 1 is a diagram showing the configuration of an endoscope system according to an embodiment. Fig. 2 is a diagram showing the configuration of an endoscope system according to an embodiment. Fig. 3 is a block diagram showing the configuration of an imaging control subsystem and a video equipment control subsystem. Fig. 4 is a diagram explaining pre-freezing. Fig. 5 is a diagram explaining a first modification of the embodiment. Fig. 6 is a diagram explaining a second modification of the embodiment.

[0020] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below. Furthermore, in the description of the drawings, the same parts are given the same reference numerals.

[0021] 1 and 2 are diagrams showing the configuration of an endoscope system 1 according to an embodiment. The endoscope system 1 corresponds to a medical system according to the present invention. This endoscope system 1 is used in the medical field and is a system for observing the inside of a subject (inside a living organism) using an endoscope 2. As shown in FIGS. 1 and 2 , this endoscope system 1 includes an endoscope 2, a light source device 3, a processing device 4, and a display device 5.

[0022] The endoscope 2 corresponds to an imaging device according to the present invention. In this embodiment, the endoscope 2 is a so-called flexible endoscope. A portion of the endoscope 2 is inserted into a living body, images the inside of the living body, and outputs image signals generated by the image capture. As shown in FIG. 1 , the endoscope 2 includes an insertion section 21, an operation section 22, and a universal cord 23.

[0023] The insertion section 21 is a section that is at least partially flexible and is inserted into a living body. As shown in Figures 1 and 2, the insertion section 21 includes a distal end section 24, a freely bendable bending section 25 (Figure 1) composed of a plurality of bending pieces, and a long, flexible flexible tube section 26 (Figure 1) that is connected to the proximal end side of the bending section 25. An imaging section 244 (Figure 2) is built into the distal end section 24. The insertion section 21 is inserted into a living body, and captures an image of a subject (object of observation) such as biological tissue that is located in a position where external light does not reach, using the imaging section 244.

[0024] The operation unit 22 is connected to the base end portion of the insertion section 21. The operation unit 22 receives various operations for the endoscope 2. As shown in Fig. 1 , the operation unit 22 includes a bending knob 221 for bending the bending section 25 in the up-down and left-right directions, a treatment tool insertion section 222 that extends from the operation unit 22 to the tip of the insertion section 21 and inserts treatment tools such as biopsy forceps, an electric scalpel, and an examination probe into the body cavity of the subject, an air supply conduit 223 that extends from the operation unit 22 to the tip of the insertion section 21 and supplies air into the body cavity of the subject, and a plurality of switches 224 for operating peripheral devices such as an air supply device (not shown) and a water supply device (not shown) and for selecting a frozen image.

[0025] The universal cord 23 incorporates at least a light guide 241 ( FIG. 2 ) and a cable assembly 245 ( FIG. 2 ) that bundles one or more signal lines. The light guide 241 is made of glass fiber or the like and forms a light guide path for light emitted by the light source device 3. As shown in FIG. 1 , the universal cord 23 branches at the end opposite to the end connected to the operation unit 22. A connector 231 that can be detachably attached to the light source device 3 is provided at the branched end of the universal cord 23. A portion of the light guide 241 extends from the end of the connector 231. The universal cord 23 transmits illumination light emitted from the light source device 3 to the distal end 24 via the connector 231 (light guide 241), the operation unit 22, and the flexible tube portion 26. The universal cord 23 also transmits image signals captured by an imaging unit 244 provided at the distal end 24 to the light source device 3. The cable assembly 245 includes a signal line for transmitting an image signal, a signal line for transmitting a drive signal for driving the imaging unit 244, and a signal line for transmitting and receiving information including unique information related to the endoscope 2 (imaging unit 244). Note that, in the present embodiment, the signal lines are described as transmitting electrical signals, but they may also be used to transmit optical signals, or may be used to transmit signals between the endoscope 2 and the light source device 3 by wireless communication.

[0026] The output end side of the light guide 241 is inserted into the tip portion 24. As shown in Fig. 2, the tip portion 24 includes an illumination lens 242, an optical system 243 for collecting light, and an imaging unit 244 that is provided at the imaging position of the optical system 243 and receives the light collected by the optical system 243, photoelectrically converts the light into an electrical signal, and performs predetermined signal processing.

[0027] The optical system 243 is configured using one or more lenses, and forms a subject image on the light receiving surface of an image sensor 244a that configures the imaging unit 244. The optical system 243 may have an optical zoom function that changes the angle of view and a focus function that changes the focus.

[0028] The imaging unit 244 captures an image of the observation target under the control of the light source device 3. As shown in Fig. 2, the imaging unit 244 includes an imaging element 244a and a signal processing unit 244b.

[0029] The image sensor 244a receives the subject image transmitted through the optical system 243 and converts it into an electrical signal (analog signal). Examples of the image sensor 244a include a CMOS (Complementary Metal Oxide Semiconductor), which is a rolling shutter type image sensor in which multiple pixels are arranged two-dimensionally in horizontal line units, and a CCD (Charge Coupled Device), which is a global shutter type image sensor. Examples of the image sensor 244a include a monochrome image sensor without a color filter on its light-receiving surface, and a color image sensor with a color filter on its light-receiving surface. Examples of the color filter include an RGB primary color filter consisting of three colors: red, green, and blue, and a CMYG complementary color filter consisting of four colors: cyan, magenta, yellow, and green. Hereinafter, when the image sensor 244a is a monochrome image sensor (an image sensor that sequentially captures subject images corresponding to red, green, and blue illumination light using a frame sequential method), the image sensor 244a will be referred to as a frame sequential sensor. Furthermore, among color image sensors, an image sensor 244a having an RGB primary color filter on its light receiving surface is referred to as a Bayer sensor, and further, among color image sensors, an image sensor 244a having a CMYG complementary color filter on its light receiving surface is referred to as a complementary color sensor.

[0030] For ease of explanation, the image signal generated by the image sensor 244a capturing an image will be referred to as a captured image below.

[0031] The signal processing unit 244b outputs a captured image (digital signal) by performing signal processing on the captured image (analog signal) generated by the imaging element 244a under the control of the light source device 3. For example, the signal processing unit 244b performs signal processing on the captured image (analog signal) generated by the imaging element 244a, such as processing to remove reset noise, processing to multiply the analog signal by an analog gain that amplifies the analog signal (hereinafter referred to as analog gain adjustment processing), and A / D conversion.

[0032] Here, the endoscope 2 has a storage unit that stores data including identification information of the endoscope 2. The identification information includes the endoscope 2's unique information (ID), model year, specification information, transmission method, information about the imaging unit 244 (imaging element 244a) used in the endoscope 2 (such as the type of the imaging element 244a (e.g., whether the imaging element 244a is a Bayer sensor, a complementary color sensor, or a frame sequential sensor) and characteristics of the imaging element 244a (defective pixels, sensitivity characteristics, etc.)). The storage unit may also temporarily store captured images generated by the imaging unit 244.

[0033] The light source device 3 corresponds to a first image processing device according to the present invention. As shown in FIG. 2, the light source device 3 includes a scope interface subsystem 31, an imaging control subsystem 32, and a light source unit 33.

[0034] The scope interface subsystem 31 is a part that connects the endoscope 2 (imaging unit 244) so ​​that captured images and the like can be communicated. The scope interface subsystem 31 is configured using an interface circuit and the like including a connector to which a cable capable of image transmission and communication is connected. The scope interface subsystem 31 receives captured images and transmits control signals and the like to the endoscope 2.

[0035] The imaging control subsystem 32 performs first image processing on the captured image received through the scope interface subsystem 31. This imaging control subsystem 32 is configured using a general-purpose processor such as a CPU (Central Processing Unit) that executes processing according to a specific program (including the image selection program according to the present invention), or a dedicated processor such as an ASIC (Application Specific Integrated Circuit) or various arithmetic circuits that execute specific functions. The imaging control subsystem 32 may also be configured using an FPGA (Field-Programmable Gate Array). The detailed configuration of the imaging control subsystem 32 will be described later in "Configuration of the Imaging Control Subsystem and the Video Equipment Control Subsystem."

[0036] The light source unit 33 emits light under the control of the scope interface subsystem 31. The light source unit 33 is realized using any light source such as an LED (Light Emitting Diode) light source, a laser light source, a xenon lamp, or a halogen lamp. The light source unit 33 may also have one or more lenses. The light generated by the light source unit 33 passes through the light guide 241 and the illumination lens 242 and is emitted from the tip of the tip unit 24 toward the object of observation.

[0037] Examples of light emitted from the light source unit 33 include light having a wavelength band of visible light (white light), narrowband light having light in a specific wavelength band, or excitation light that excites substances contained in the object of observation.

[0038] The processing device 4 corresponds to a second image processing device according to the present invention. As shown in FIG.

[0039] The video equipment control subsystem 41 is communicatively connected to the display device 5, and performs second image processing on the captured image that has undergone first image processing and that has been received from the imaging control subsystem 32 via the transmission cable 28, to generate a display image. The video equipment control subsystem 41 then outputs the display image to the display device 5. As a result, the display image is displayed on the display device 5. The video equipment control subsystem 41 is configured using a general-purpose processor such as a CPU that executes processing according to a specific program (including the image selection program of the present invention), or a dedicated processor such as an ASIC or various arithmetic circuits that execute specific functions. The video equipment control subsystem 41 may also be configured using an FPGA. The detailed configuration of the video equipment control subsystem 41 will be described later in "Configuration of the Imaging Control Subsystem and the Video Equipment Control Subsystem."

[0040] The display device 5 displays the display image received from the processing device 4 (video device control subsystem 41) via the video cable. The display device 5 is configured using a monitor such as a liquid crystal or organic EL (Electro Luminescence) monitor.

[0041] [Configuration of the Imaging Control Subsystem and the Video Equipment Control Subsystem] Fig. 3 is a block diagram showing the configuration of the imaging control subsystem 32 and the video equipment control subsystem 41. Fig. 4 is a diagram explaining pre-freeze. Specifically, the horizontally extending arrows in Fig. 4 indicate the passage of time. The endoscope system 1 according to this embodiment is configured to be able to execute a pre-freeze function. Specifically, as shown in Fig. 4, pre-freeze is a function that selects a frozen image F1, which is the image with the best image quality, from a plurality of chronologically consecutive captured images F0 captured during a certain period preceding the moment when the user operated the switch 224 (a freeze instruction).

[0042] As shown in FIG. 3, the imaging control subsystem 32 includes an imaging correction processing unit 321, an NR processing unit 322, a synchronization processing unit 323, an image memory 324, a color adjustment processing unit 325, a blur / color shift evaluation unit 326, a gamma processing unit 327, a halation / blur evaluation unit 328, a system control unit 329, and an image selection unit 320.

[0043] When the endoscope 2 is connected to the light source device 3, the image correction processing unit 321 corrects defective pixels and variations in sensitivity characteristics of the image sensor 244a by performing first image processing on the captured image received through the scope interface subsystem 31 based on information obtained from the endoscope 2 (identification of the image sensor 244a).

[0044] When the endoscope 2 is connected to the light source device 3, the NR processing unit 322 performs noise reduction processing (first image processing) to remove random noise and fixed pattern noise in the captured image corrected by the image correction processing unit 321 based on information acquired from the endoscope 2 (information regarding the image sensor 244a).

[0045] The synchronization processing unit 323 performs first image processing (synchronization processing) on ​​the captured image on which the noise reduction processing has been performed by the NR processing unit 322 .

[0046] The image memory 324 is capable of temporarily storing multiple frames of captured images sequentially output from the synchronization processing unit 323. The multiple frames of captured images stored in the image memory 324 are then output to the color adjustment processing unit 325 in order from the oldest captured image frame.

[0047] When the endoscope 2 is connected to the light source device 3, the color adjustment processing unit 325 performs color adjustment processing (first image processing) to correct color variations in the captured image output from the image memory 324 based on information acquired from the endoscope 2 (information regarding the image sensor 244a).

[0048] The blur / color shift evaluation unit 326 corresponds to the evaluation unit according to the present invention. The blur / color shift evaluation unit 326 calculates a blur evaluation value that evaluates the degree of blur in the captured image corrected by the image correction processing unit 312a and a color shift evaluation value that evaluates the degree of color shift in the captured image. Here, the blur / color shift evaluation unit 326 may calculate the blur (blur evaluation value) directly from the captured image, or may calculate it based on a change in the subject position between chronologically consecutive captured images, i.e., a so-called motion vector. In this embodiment, in order to avoid being affected by the noise reduction process, the blur / color shift evaluation unit 326 calculates the blur evaluation value and color shift evaluation value from the captured image before the noise reduction process is performed.

[0049] The gamma processing unit 327 performs gamma processing to adjust the overall contrast of the captured image that has undergone color adjustment processing by the color adjustment processing unit 325 .

[0050] 3, the video device control subsystem 41 includes a gamma processing unit 411. Similar to the gamma processing unit 327, this gamma processing unit 411 acquires a captured image that has undergone color adjustment processing by the color adjustment processing unit 325, and performs gamma processing (second image processing) on ​​the captured image. The captured image (display image) that has undergone gamma processing by the gamma processing unit 411 is then displayed on the display device 5.

[0051] The halation / blur evaluation unit 328 corresponds to an evaluation unit according to the present invention. The halation / blur evaluation unit 328 calculates a halation evaluation value for evaluating the degree of halation in a captured image on which the gamma processing unit 327 has performed gamma processing, and a blur evaluation value for evaluating the degree of blur in the captured image. Here, the halation / blur evaluation unit 328 calculates the halation evaluation value based on, for example, the number of pixels whose luminance value is greater than a predetermined value. The halation / blur evaluation unit 328 also calculates the blur evaluation value based on a luminance edge amount calculated after reducing the captured image by half to mitigate the influence of noise. In addition, in a captured image with color shift, there is a possibility that the edge amount will be overestimated due to a shift between the edges of the RGB components. Therefore, the halation / blur evaluation unit 328 may correct the blur evaluation value based on the shift between the edges of the RGB components, thereby reducing the blur evaluation value in a captured image with color shift. Furthermore, an area corresponding to a bright spot (a highlight occurring in an image due to light reflected from a subject) in the captured image may be detected from the luminance value, and the edge amount in the detected area may be corrected to mitigate the influence of the edge component resulting from the bright spot, thereby calculating the blur evaluation value. Note that in this embodiment, since it is necessary to calculate the halation evaluation value and the blur evaluation value with the brightness of the final image, the halation / blur evaluation unit 328 calculates the halation evaluation value and the blur evaluation value from the captured image on which gamma processing has been performed.

[0052] The system control unit 329 detects a user operation (freeze instruction) on the switch 224. Then, the system control unit 329 outputs a signal corresponding to the freeze instruction to the image selection unit 320.

[0053] The image selection unit 320 executes the following image selection process based on a signal (freeze instruction) output from the system control unit 329. Here, the image selection unit 320 includes an evaluation value memory 3201, as shown in FIG. 3 . This evaluation value memory 3201 stores the blur evaluation value and color shift evaluation value calculated by the blur / color shift evaluation unit 326 in association with identification information (e.g., a timestamp attached to the captured image) that identifies the captured image used to calculate the blur evaluation value and color shift evaluation value. The evaluation value memory 3201 also stores the halation evaluation value and blur evaluation value calculated by the halation / blur evaluation unit 328 in association with identification information (e.g., a timestamp attached to the captured image) that identifies the captured image used to calculate the halation evaluation value and blur evaluation value.

[0054] When a freeze instruction is received, the image selection unit 320 extracts from the evaluation value memory 3201 blur evaluation values, color shift evaluation values, halation evaluation values, and blur evaluation values ​​associated with the identification information of multiple chronologically consecutive captured images F0 captured within a certain period preceding the moment the freeze instruction was received. The image selection unit 320 then compares the extracted blur evaluation values, color shift evaluation values, halation evaluation values, and blur evaluation values ​​with their corresponding thresholds to search for identification information (e.g., timestamps attached to the captured images) identifying the captured image with the best overall image quality. The image selection unit 320 then outputs a control signal and identification information (e.g., timestamps attached to the captured images) identifying the selected captured images to the image memory 324. The image memory 324 then outputs the captured image corresponding to the identification information (e.g., timestamps attached to the captured images) identifying the selected captured images as the frozen image F1 to the color adjustment processing unit 325.

[0055] The freeze image F1 is then subjected to color adjustment processing by the color adjustment processing unit 325 and gamma processing by the gamma processing unit 411, and then displayed on the display device 5.

[0056] The present embodiment described above provides the following advantages: The endoscope system 1 according to the present embodiment includes the light source device 3 that performs first image processing on an image captured by the endoscope 2, and the processing device 4 that performs second image processing on the image after the first image processing has been performed. Therefore, for example, when updating only the configuration that performs either the first or second image processing, it is not necessary to update both the light source device 3 and the processing device 4.

[0057] The light source device 3 also includes a blur / color shift evaluation unit 326 and a halation / blur evaluation unit 328 that calculate evaluation values ​​for each of a plurality of chronologically consecutive captured images F0 to select a freeze image F1 to be displayed on the display device 5 from the plurality of captured images F0, and an image selection unit 320 that selects a freeze image F1 from the plurality of captured images F0 based on the evaluation values. Therefore, it is not necessary to transmit the evaluation values ​​calculated by the blur / color shift evaluation unit 326 and the halation / blur evaluation unit 328 from the processing device 4 to the light source device 3 in a direction opposite to the flow of captured images (the flow from the light source device 3 to the processing device 4). Therefore, with the endoscope system 1 according to this embodiment, there is no time lag between the issuance of a freeze instruction and the display of the freeze image F1, thereby improving convenience.

[0058] Other Embodiments Although the embodiments for carrying out the present invention have been described above, the present invention should not be limited to the above-described embodiments. In the above-described embodiments, the configurations of the following modified examples 1 and 2 may be adopted.

[0059] (Variation 1) Fig. 5 is a diagram illustrating Variation 1 of the embodiment. Specifically, Fig. 5 is a diagram corresponding to Fig. 3. In the above-described embodiment, the imaging control subsystem 32 and the video equipment control subsystem 41 may have the configuration of Variation 1 shown in Fig. 5.

[0060] 5, in this modified example 1, the image memory 324, color adjustment processing section 325, halation / blur evaluation section 328, system control section 329, and image selection section 320 (including evaluation value memory 3201), which are described in the above-described embodiment, are moved from the imaging control subsystem 32 to the video equipment control subsystem 41. Furthermore, the flow of captured images (solid arrows), which are image signals, the flow of freeze instructions from the endoscope 2 (dashed arrows), the flow of evaluation values ​​from the shake / color shift evaluation section 326 and the halation / blur evaluation section 328 (dashed arrows), and the flow of control signals from the image selection section 320 (dashed arrows) are the same as in the above-described embodiment.

[0061] In this first modification, the blur / color shift evaluation unit 326 corresponds to the first evaluation unit according to the present invention. The blur evaluation value and the color shift evaluation value correspond to the first evaluation value according to the present invention. The halation / blur evaluation unit 328 corresponds to the second evaluation unit according to the present invention. The halation evaluation value and the blur evaluation value correspond to the second evaluation value according to the present invention.

[0062] Even when configured as in the above-described first modification, the same effects as those of the above-described embodiment are achieved.

[0063] (Modification 2) Fig. 6 is a diagram illustrating Modification 2 of the embodiment. Specifically, Fig. 6 corresponds to Fig. 3. In the above-described embodiment, the imaging control subsystem 32 and the video equipment control subsystem 41 may be configured as in Modification 2 shown in Fig. 6.

[0064] 6, in this second modification, the noise reduction processing unit 322, synchronization processing unit 323, image memory 324, color adjustment processing unit 325, blur / color shift evaluation unit 326, halation / blur evaluation unit 328, system control unit 329, and image selection unit 320 (including evaluation value memory 3201), which are described in the above-described embodiment, are moved from the imaging control subsystem 32 to the video equipment control subsystem 41. Furthermore, the flow of captured images (solid arrows), which are image signals, the flow of freeze instructions from the endoscope 2 (dashed arrows), the flow of evaluation values ​​from the blur / color shift evaluation unit 326 and the halation / blur evaluation unit 328 (dashed arrows), and the flow of control signals from the image selection unit 320 (dashed arrows) are the same as in the above-described embodiment.

[0065] Even when configured as in the second modified example described above, the same effects as those of the above-described embodiment are achieved.

[0066] In the above-described embodiment and modifications 1 and 2, the processing device 4 may be configured by a server device such as a cloud server.

[0067] In the above-described embodiment and modifications 1 and 2, the evaluation value for the captured image F0 may be at least one of a blur evaluation value, a color shift evaluation value, a halation evaluation value, and a blur evaluation value.

[0068] REFERENCE SIGNS LIST 1 Endoscope system 2 Endoscope 3 Light source device 4 Processing device 5 Display device 21 Insertion section 22 Operation section 23 Universal cord 24 Tip section 25 Bending section 26 Flexible tube section 28 Transmission cable 31 Scope interface subsystem 32 Imaging control subsystem 33 Light source section 41 Video equipment control subsystem 221 Bending knob 222 Treatment tool insertion section 223 Air supply conduit 224 Switch 231 Connector 241 Light guide 242 Illumination lens 243 Optical system 244 Imaging section 244a Imaging element 244b Signal processing section 245 Collector cable 321 Imaging correction processing section 322 NR processing section 323 Synchronization processing section 324 Image memory 325 Color adjustment processing section 326 Blur / color shift evaluation section 327 Gamma processing section 328 Halation / blur evaluation unit 329 System control unit 320 Image selection unit 411 Gamma processing unit 3201 Evaluation value memory F0 Captured image F1 Freeze image

Claims

1. A medical system comprising: a first image processing device that performs first image processing on captured images captured by an imaging device; and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, wherein the first image processing device comprises: an evaluation unit that calculates an evaluation value for each of the captured images in time series to select a freeze image to be displayed on a display device from the captured images; and an image selection unit that obtains the evaluation value for each of the captured images and selects the freeze image from the captured images based on the evaluation value.

2. A medical system according to claim 1, wherein the first image processing device is provided with a light source unit that supplies the imaging device with specific light for irradiating the subject being imaged by the imaging device.

3. The medical system of claim 1, wherein the evaluation value is at least one of a blur evaluation value that evaluates the degree of blur in the captured image, a color shift evaluation value that evaluates the degree of color shift in the captured image, a halation evaluation value that evaluates the degree of halation in the captured image, and a blur evaluation value that evaluates the degree of blur in the captured image.

4. A medical system comprising: a first image processing device that performs first image processing on captured images captured by an imaging device; and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, wherein the first image processing device comprises: a first evaluation unit that calculates a first evaluation value for each of the captured images in order to select a freeze image to be displayed on a display device from among the captured images that are consecutive in time series; and the second image processing device comprises: a second evaluation unit that calculates a second evaluation value for each of the captured images in order to select the freeze image from among the captured images; and an image selection unit that acquires the first evaluation value and the second evaluation value for each of the captured images and selects the freeze image from among the captured images based on the first evaluation value and the second evaluation value.

5. A medical system according to claim 4, wherein the first image processing device is provided with a light source unit that supplies the imaging device with specific light for irradiating a subject to be imaged by the imaging device.

6. The medical system described in claim 5, wherein the first evaluation value is at least one of a blur evaluation value that evaluates the degree of blur in the captured image and a color shift evaluation value that evaluates the degree of color shift in the captured image, and the second evaluation value is at least one of a halation evaluation value that evaluates the degree of halation in the captured image and a blur evaluation value that evaluates the degree of blur in the captured image.

7. A medical system comprising: a first image processing device that performs first image processing on captured images captured by an imaging device; and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, wherein the second image processing device comprises: an evaluation unit that calculates an evaluation value for each of the captured images in chronological order to select a freeze image to be displayed on a display device from among the captured images; and an image selection unit that obtains the evaluation value for each of the captured images and selects the freeze image from among the captured images based on the evaluation value.

8. A medical system according to claim 7, wherein the first image processing device comprises a light source unit that supplies the imaging device with specific light for irradiating a subject to be imaged by the imaging device.

9. The medical system of claim 7, wherein the evaluation value is at least one of a blur evaluation value that evaluates the degree of blur in the captured image, a color shift evaluation value that evaluates the degree of color shift in the captured image, a halation evaluation value that evaluates the degree of halation in the captured image, and a blur evaluation value that evaluates the degree of blur in the captured image.

10. An image selection method executed by a medical system, the medical system comprising a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, wherein the first image processing device calculates an evaluation value for each of a plurality of chronologically consecutive captured images to select a freeze image to be displayed on a display device from the plurality of captured images, and selects the freeze image from the plurality of captured images based on the evaluation value for each of the plurality of captured images.

11. An image selection method executed by a medical system, the medical system comprising a first image processing device that performs first image processing on captured images captured by an imaging device, and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, wherein the first image processing device calculates a first evaluation value for each of the captured images that are chronologically consecutive, to select a freeze image to be displayed on a display device from the captured images, and the second image processing device calculates a second evaluation value for each of the captured images to select the freeze image from the captured images, and the image selection method selects the freeze image from the captured images based on the first evaluation value and the second evaluation value for each of the captured images.

12. An image selection method executed by a medical system, the medical system comprising a first image processing device that performs first image processing on an image captured by an imaging device, and a second image processing device that performs second image processing on the image after the first image processing has been performed, wherein the second image processing device calculates an evaluation value for each of a plurality of chronologically consecutive captured images to select a freeze image to be displayed on a display device from the plurality of captured images, and selects the freeze image from the plurality of captured images based on the evaluation value for each of the plurality of captured images.

13. An image selection program executed by a medical system, the medical system comprising: a first image processing device that performs first image processing on an image captured by an imaging device; and a second image processing device that performs second image processing on the image after the first image processing has been performed, the image selection program causing the medical system to execute the steps of: the first image processing device calculating an evaluation value for each of a plurality of captured images that are chronologically consecutive, in order to select a freeze image to be displayed on a display device from the plurality of captured images; and selecting the freeze image from the plurality of captured images based on the evaluation value for each of the plurality of captured images.

14. An image selection program executed by a medical system, the medical system comprising: a first image processing device that performs first image processing on captured images captured by an imaging device; and a second image processing device that performs second image processing on the captured images after the first image processing has been performed, the image selection program causing the medical system to execute the following steps: a step in which the first image processing device calculates a first evaluation value for each of the captured images in chronological order to select a freeze image to be displayed on a display device from the captured images; and a step in which the second image processing device calculates a second evaluation value for each of the captured images in order to select the freeze image from the captured images, and selects the freeze image from the captured images based on the first evaluation value and the second evaluation value for each of the captured images.

15. An image selection program executed by a medical system, the medical system comprising: a first image processing device that performs first image processing on an image captured by an imaging device; and a second image processing device that performs second image processing on the image after the first image processing has been performed, the image selection program causing the medical system to execute the steps of: the second image processing device calculating an evaluation value for each of a plurality of captured images that are chronologically consecutive, in order to select a freeze image to be displayed on a display device from the plurality of captured images; and selecting the freeze image from the plurality of captured images based on the evaluation value for each of the plurality of captured images.

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