JP2015047440A - Processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To address a decrease in a contrast of a specific bio-structure in a spectral image with a structure other than that.SOLUTION: A processor includes luminance value acquisition means that acquires a luminance value of a pixel of interest in a pixel group having a prescribed color array, calculates a signal of the pixel of interest using a signal of a pixel having a peak sensitivity at a specific wavelength region for highlighting a specific bio-structure in peripheral pixels located in the periphery of the pixel of interest so as to increase the sensitivity of the specific wavelength region at the pixel of interest, and acquires a luminance value of the pixel of interest using the signal, the sensitivity of the specific wavelength region of which is increased.

Description

  The present invention relates to a processor that allows an operator to observe a specific anatomy.

  Electronic endoscope systems for observing subjects such as lesions are used in medical settings. As an example of a medical electronic endoscope system, one capable of allowing a surgeon to observe a specific biological structure is known (for example, see Patent Document 1). This type of electronic endoscope system including the electronic endoscope system described in Patent Document 1 irradiates and irradiates a subject with light in a wavelength region having high absorption characteristics with respect to a specific biological structure. A return light from the subject is received, and a spectroscopic image that emphasizes a specific anatomy is generated using the received return light.

Japanese Patent No. 3607857

  The electronic endoscope system described in Patent Literature 1 generates a spectral image of a specific living body structure (for example, a blood vessel structure), so that white irradiation light emitted from a light source is narrow-banded through a predetermined narrow-band filter. The living body is irradiated with the irradiation light having a narrow band. Ideally, this type of narrow band filter has a characteristic of transmitting only light in a wavelength region suitable for blood vessel enhancement. However, an actual narrow band filter has a transmission peak in a wavelength range suitable for blood vessel enhancement and a certain half width, and transmits light in a wavelength region other than the wavelength region suitable for blood vessel enhancement. . Therefore, there is a problem that the entire image becomes bright and the contrast between the blood vessel structure and other structures (for example, mucous membrane structure) decreases.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a processor suitable for improving the contrast between a specific anatomy and other structures in a spectral image. It is.

  A processor according to an embodiment of the present invention includes a luminance value acquisition unit that acquires a luminance value of a pixel of interest in a pixel group having a predetermined color arrangement. The luminance value acquisition means calculates a signal of the pixel of interest using a signal of a pixel having a peak sensitivity in a specific wavelength region for emphasizing a specific anatomy among peripheral pixels located around the pixel of interest, The sensitivity of the specific pixel in the target wavelength region is increased, and the luminance value of the target pixel is acquired using the signal whose sensitivity in the specific wavelength region is increased.

  According to the present embodiment, for example, a pixel (dark portion) in which a specific biological structure is captured and a pixel (light portion) in which a specific biological structure is captured are increased by increasing the luminance of the pixels in which the specific biological structure is captured. Contrast is improved.

  The specific wavelength range is, for example, a wavelength range where hemoglobin absorption is large.

  The processor may be configured to include a light source that emits light including a visible light region, and an optical filter that filters irradiation light emitted from the light source into narrowband light corresponding to a specific wavelength region. In this configuration, the luminance value acquisition means receives a signal of each pixel constituting a pixel group having a predetermined color arrangement from a predetermined external device that images a subject irradiated with narrow band light.

  The processor may be configured to include an optical filter switching unit that inserts or retracts an optical filter with respect to an irradiation optical path of the light source, and an operation unit that receives an input operation by the user. In this configuration, the optical filter switching means inserts the optical filter into the irradiation optical path or retracts from the irradiation optical path in accordance with the input operation received by the operation means.

  The luminance value acquisition means acquires the luminance value of the pixel of interest in the pixel group without performing the above-described processing for increasing the sensitivity during the period when the optical filter is withdrawn from the irradiation optical path, and the optical filter is inserted into the irradiation optical path. During this period, the luminance value of the target pixel in the pixel group may be acquired after performing the above-described processing for increasing the sensitivity.

  The processor may be configured to include matrix calculation means for performing matrix calculation on the signal of each pixel. In this configuration, the matrix calculation means performs matrix calculation using the first matrix coefficient during the period in which the optical filter is withdrawn from the irradiation optical path, and during the period in which the optical filter is inserted into the irradiation optical path, The matrix operation is performed using a second matrix coefficient different from the matrix coefficient.

  According to the embodiment of the present invention, a processor suitable for improving the contrast between a specific anatomy and other structures in a spectroscopic image is provided.

1 is an external view of an electronic endoscope system according to an embodiment of the present invention. 1 is a block diagram of an electronic endoscope system according to an embodiment of the present invention. It is a figure which shows the example of the spectral characteristics of the optical filter with which the processor of embodiment of this invention was equipped. It is a figure which shows the absorption characteristic of hemoglobin. It is a figure which shows pixel arrangement | positioning of the solid-state image sensor with which the electronic scope of embodiment of this invention was equipped. It is a figure which shows the spectral characteristics of a mixed signal (Wr, Gb, Wb, Gr). It is a figure for demonstrating the brightness | luminance correction process by the 2nd front | former stage process circuit with which the processor of embodiment of this invention was equipped. It is the figure which shows typically the blood vessel structure of surface layer vicinity and a deep layer, and the figure which shows the example of a spectral image displayed on the display screen of a monitor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, an electronic endoscope system will be described as an example of an embodiment of the present invention.

[Overall configuration of electronic endoscope system 1]
FIG. 1 is an external view of an electronic endoscope system 1 according to the present embodiment. As shown in FIG. 1, the electronic endoscope system 1 of the present embodiment includes an electronic scope 100 and a processor 200. The processor 200 is an apparatus that integrally includes a signal processing device that processes a signal from the electronic scope 100 and a light source device that irradiates a body cavity that does not reach natural light through the electronic scope 100. In another embodiment, the signal processing device and the light source device may be configured separately.

  As shown in FIG. 1, the electronic scope 100 includes an insertion portion flexible tube 11 covered with a flexible sheath. The distal end portion (bent portion 14) of the insertion portion flexible tube 11 bends in response to a remote operation from the hand operation portion 13 connected to the proximal end of the insertion portion flexible tube 11. The bending mechanism is a well-known mechanism incorporated in a general endoscope, and the bending portion 14 is bent by pulling the operation wire in conjunction with the rotation operation of the bending operation knob of the hand operation portion 13. The proximal end of the distal end portion 12 covered with a hard resin housing is connected to the distal end of the bent portion 14. When the direction of the distal end portion 12 changes according to the bending operation by the rotation operation of the bending operation knob, the imaging region by the electronic scope 100 moves.

  The processor 200 is provided with a connector portion 20 having a connection structure corresponding to the connector portion 10 provided at the proximal end of the electronic scope 100. The connector unit 20 is mechanically connected to the connector unit 10 to electrically and optically connect the electronic scope 100 and the processor 200.

  FIG. 2 is a block diagram showing a configuration of the electronic endoscope system 1 of the present embodiment. As shown in FIG. 2, a monitor 300 is connected to a processor 200 in the electronic endoscope system 1.

  As illustrated in FIG. 2, the processor 200 includes a system controller 202 and a timing controller 204. The system controller 202 performs overall control of the entire electronic endoscope system 1 by executing various programs stored in the memory 222. Further, the system controller 202 changes various settings of the electronic endoscope system 1 in accordance with instructions from the user (surgeon or assistant) input to the operation panel 218. The timing controller 204 outputs a clock pulse for adjusting the operation timing of each unit to each circuit in the electronic endoscope system 1.

  After starting by the lamp power igniter 206, the lamp 208 emits light having a spectrum (or light including at least the visible light region) mainly extending from the visible light region to the invisible infrared light region. A high-intensity lamp such as a xenon lamp, a halogen lamp, or a metal halide lamp is suitable for the lamp 208. Irradiation light emitted from the lamp 208 is limited to an appropriate amount of light through the diaphragm 212 while being collected by the condenser lens 210.

  A motor 214 is mechanically connected to the diaphragm 212 via a transmission mechanism such as an arm or a gear (not shown). The motor 214 is a DC motor, for example, and is driven under the drive control of the driver 216. The aperture 212 is operated by the motor 214 to change the opening degree so that the image displayed on the display screen of the monitor 300 has an appropriate brightness. The amount of light emitted from the lamp 208 is limited according to the opening degree of the diaphragm 212. The appropriate reference for the brightness of the image is changed according to the brightness adjustment operation of the operation panel 218 by the operator. Note that the dimming circuit that controls the brightness by controlling the driver 216 is a well-known circuit and is omitted in this specification.

  There are various configurations for the operation panel 218. As a specific configuration of the operation panel 218, for example, a hardware key for each function mounted on the front surface of the processor 200, a touch panel GUI (Graphical User Interface), a combination of a hardware key and a GUI, or the like can be considered.

  The irradiation light that has passed through the diaphragm 212 is split by the optical filter 213. Irradiation light dispersed by the optical filter 213 is incident on an incident end of an LCB (Light Carrying Bundle) 102. 3A and 3B illustrate the spectral characteristics of the optical filter 213, respectively. In each of FIGS. 3A and 3B, the vertical axis indicates the transmittance, and the horizontal axis indicates the wavelength (unit: nm). FIG. 4 shows the absorption characteristics of hemoglobin. In FIG. 4, the vertical axis represents the absorptance, and the horizontal axis represents the wavelength (unit: nm). As can be seen from FIGS. 3 and 4, the optical filter 213 has a transmission peak in a wavelength region with high absorption characteristics for hemoglobin (a wavelength region near 420 nm or 550 nm). Light in the wavelength region near 420 nm is suitable for observing the blood vessel structure near the surface layer, and light in the wavelength region near 550 nm is suitable for observing the deep blood vessel structure.

  A motor 215 driven under the drive control of the driver 216 is mechanically coupled to the optical filter 213 via a transmission mechanism such as an arm or a gear (not shown). The motor 215 inserts the optical filter 213 into the optical path or retracts it from the optical path in response to a mode switching operation (described later) of the operation panel 218 by the operator. During the period in which the optical filter 213 is retracted from the optical path, the irradiation light that has passed through the diaphragm 212 is directly incident on the incident end of the LCB 102. The motor 215 is, for example, a galvano motor or a servo motor.

  Irradiation light incident on the LCB 102 from the incident end propagates by repeating total reflection in the LCB 102. Irradiation light propagating through the LCB 102 is emitted from the exit end of the LCB 102 disposed in the distal end portion 12 of the electronic scope 100, and irradiates the subject via the light distribution lens 104.

  Return light from the subject forms an optical image at each pixel on the light receiving surface of the solid-state image sensor 108 via the objective lens 106. FIG. 5 is a diagram illustrating a pixel arrangement of the solid-state image sensor 108. As shown in FIG. 5, the solid-state imaging device 108 is an interlaced single-plate color CCD (Charge Coupled Device) image sensor having a complementary color checkered pixel arrangement. The solid-state image sensor 108 accumulates an optical image formed by each pixel on the light receiving surface as a charge corresponding to the amount of light, and obtains complementary colors signals of yellow Ye, cyan Cy, green G, and magenta Mg.

The solid-state image sensor 108 adds, mixes and outputs complementary color signals of two pixels adjacent in the vertical direction in order to substantially improve sensitivity and frame rate. There are four types of mixed signals (Wr, Gb, Wb, Gr), which are defined as follows.
Wr = Mg + Ye
Gb = G + Cy
Wb = Mg + Cy
Gr = G + Ye

  The solid-state imaging device 108 outputs mixed signals Wr and Gb from the N1 line and outputs mixed signals Wb and Gr from the N2 line in the odd field. In the even field, the combination to be mixed is changed, and the mixed signals Wb and Gr are output from the N1 ′ line shifted by 1 line from the N1 line, and the mixed signals Wr and Gb are output from the N2 ′ line shifted by 1 line from the N2 line. Output. The mixed signals (Wr, Gb, Wb, Gr) are input to the signal processing circuit 220 via the driver signal processing circuit 112 after signal amplification by the preamplifier 110. Note that the color array of the solid-state image sensor 108 may be, for example, a Bayer type. Further, the solid-state image sensor 108 may be replaced with a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

  The electronic scope 100 includes a driver signal processing circuit 112 and a memory 14. The driver signal processing circuit 112 accesses the memory 114 and reads unique information of the electronic scope 100. The unique information of the electronic scope 100 recorded in the memory 114 includes, for example, the number and sensitivity of the solid-state image sensor 108, the operable frame rate, the model number, and the like. The driver signal processing circuit 112 outputs the unique information read from the memory 114 to the system controller 202.

  The system controller 202 performs various calculations based on the unique information of the electronic scope 100 and generates a control signal. The system controller 202 uses the generated control signal to control the operation and timing of various circuits in the processor 200 so that processing suitable for the electronic scope connected to the processor 200 is performed.

  The timing controller 204 supplies clock pulses to the driver signal processing circuit 112 and the signal processing circuit 220 according to the timing control by the system controller 202. The driver signal processing circuit 112 drives and controls the solid-state imaging device 108 at a timing synchronized with the frame rate of the video processed on the processor 200 side, according to the clock pulse supplied from the timing controller 204.

  As shown in FIG. 2, the signal processing circuit 220 includes a selector 220a, a first pre-processing circuit 220b1, a second signal processing circuit 220b2, a matrix circuit 220c, and an image signal processing circuit 220d.

  The operation mode of the electronic endoscope system 1 is switched to the normal observation mode or the special observation mode according to the mode switching operation of the operation panel 218 by the operator. Below, operation | movement of the electronic endoscope system 1 in each mode is demonstrated.

[Normal observation mode]
The normal observation mode is a mode for displaying a normal color image on the display screen of the monitor 300. When the operation mode of the electronic endoscope system 1 is set to the normal observation mode, the optical filter 213 is retracted from the optical path. For this reason, the subject is irradiated with white irradiation light. The solid-state imaging device 108 receives the return light from the subject irradiated with the white irradiation light, and generates and outputs a mixed signal (Wr, Gb, Wb, Gr) based on the received return light. The mixed signals (Wr, Gb, Wb, Gr) output from the solid-state image sensor 108 are input to the signal processing circuit 220 via the driver signal processing circuit 112 after signal amplification by the preamplifier 110.

  At the time of setting to the normal observation mode, not only the switching operation of the optical filter 213 but also the output of the selector 220a is switched to the first pre-processing circuit 220b1. Therefore, the mixed signal (Wr, Gb, Wb, Gr) input to the signal processing circuit 220 is input to the first pre-processing circuit 220b1 via the selector 220a. The first pre-processing circuit 220b1 performs signal processing on the input mixed signals (Wr, Gb, Wb, Gr). Specifically, the first pre-processing circuit 220b1 performs predetermined signal processing such as Y / C separation and color interpolation on the input mixed signal (Wr, Gb, Wb, Gr), and after color interpolation. Are output to the matrix circuit 220c, and a luminance signal (Y) is generated from the mixed signals (Wr, Gb, Wb, Gr) and output to the image signal processing circuit 220d. The matrix circuit 220c performs a predetermined color matrix operation on the input color-interpolated signal. In the color matrix calculation, the color-interpolated signal input from the first pre-processing circuit 220b1 is multiplied by a color matrix coefficient (first coefficient) suitable for a normal color image, whereby the primary color signal (R, G, B). The converted primary color signals (R, G, B) are input to the image signal processing circuit 220d. The image signal processing circuit 220d performs predetermined signal processing such as white balance adjustment and γ correction on the primary color signals (R, G, B) input from the matrix circuit 220c, and then performs color difference signals (RY, BY) is generated. The image signal processing circuit 220d complies with predetermined standards such as NTSC (National Television System Committee) and PAL (Phase Alternating Line) with respect to the generated color difference signals (RY, BY) and luminance signal (Y). The video signal is converted into a video signal, and the converted video signal is output to the monitor 300. By sequentially inputting video signals to the monitor 300, a normal color image of the subject is displayed on the display screen of the monitor 300.

[Special observation mode]
The special observation mode is a mode in which a spectral image that emphasizes a specific anatomy is displayed on the display screen of the monitor 300. When the operation mode of the electronic endoscope system 1 is set to the special observation mode, the optical filter 213 is inserted into the optical path. Therefore, the subject is irradiated with narrowband light (see FIG. 3) by the optical filter 213. The solid-state image sensor 108 receives the return light from the subject irradiated with the narrowband light, and generates and outputs a mixed signal (Wr, Gb, Wb, Gr) based on the received return light. The mixed signals (Wr, Gb, Wb, Gr) output from the solid-state image sensor 108 are input to the signal processing circuit 220 via the driver signal processing circuit 112 after signal amplification by the preamplifier 110.

  At the time of setting to the special observation mode, not only the switching operation of the optical filter 213 but also the output of the selector 220a is switched to the second pre-processing circuit 220b2. Therefore, the mixed signals (Wr, Gb, Wb, Gr) input to the signal processing circuit 220 are input to the second pre-processing circuit 220b2 via the selector 220a.

  The second pre-processing circuit 220b2 generates the luminance value of each pixel so that the contrast between the specific biological structure and the other structure in the spectral image is improved. In this embodiment, the characteristic anatomy is a blood vessel structure in the vicinity of the surface layer or in the deep layer. Hereinafter, the wavelength range for emphasizing the blood vessel structure in the vicinity of the surface layer or in the deep layer is referred to as a “specific wavelength range”. The specific wavelength range is a wavelength range near 420 nm or 550 nm. The second pre-processing circuit 220b2 calculates a specific biological structure in the spectroscopic image and others by calculating a mixed signal (Wr, Gb, Wb, Gr) and increasing the sensitivity in a specific wavelength region in each pixel. Brightness that improves the contrast with the structure is generated.

  FIG. 6 is a diagram showing the spectral characteristics of the mixed signals (Wr, Gb, Wb, Gr). In FIG. 6, the vertical axis represents sensitivity, and the horizontal axis represents wavelength (unit: nm). As shown in FIG. 6, the mixed signal Wb among the mixed signals (Wr, Gb, Wb, Gr) is a signal having the highest sensitivity in a specific wavelength region (a wavelength region near 420 nm), and the specific wavelength region (420 nm). It has peak sensitivity in the nearby wavelength range. Of the mixed signals (Wr, Gb, Wb, Gr), the mixed signal Gr has high peak sensitivity in two specific wavelength regions (wavelength regions near 420 nm and 550 nm).

FIGS. 7A and 7B are diagrams for explaining the luminance generation processing by the second pre-processing circuit 220b2. FIG. 7A shows a layout diagram in which mixed signals (Wr, Gb, Wb, Gr) output from the solid-state imaging device 108 to odd fields are arranged according to the pixel layout. In the layout diagram of FIG. 7 (a), ordinal numbers 1 to 4 are given to the columns of the column and the row for convenience of explanation. FIG. 7B illustrates formulas (1) to (4) used when calculating mixed signals (Wr, Gb, Wb, Gr) for luminance generation. Two subscripts are attached to each symbol in the expressions (1) to (4). The subscript on the left side of each symbol represents the ordinal number of the column in the layout diagram, and the subscript on the right side represents the ordinal number of the row in the layout diagram. Expression (1) shows an arithmetic expression of the mixed signal Wr ₂₂ , Expression (2) shows an arithmetic expression of the mixed signal Gb ₂₃ , Expression (3) shows an arithmetic expression of the mixed signal Gr ₃₂ , and Expression (4) is An arithmetic expression of the mixed signal Wb ₃₃ is shown.

  As illustrated in Expression (1), the second pre-processing circuit 220b2 calculates the target pixel (mixed signal Wr) using the adjacent left and right pixels (mixed signal Gb). Further, as illustrated in Expression (2), the second pre-processing circuit 220b2 calculates the target pixel (mixed signal Gb) using the adjacent upper and lower pixels (mixed signal Wb). Further, as illustrated in Equation (3), the second pre-processing circuit 220b2 calculates the target pixel (mixed signal Gr) using the adjacent left and right pixels (mixed signal Wb). Further, as illustrated in Equation (4), the second pre-stage processing circuit 220b2 calculates the target pixel (mixed signal Wb) using adjacent pixels in the four oblique directions (mixed signal Wr). As described above, the second pre-processing circuit 220b2 calculates the target pixel using a pixel having a peak sensitivity in a specific wavelength region among peripheral pixels located in the vicinity thereof. By calculating the mixed signal (Wr, Gb, Wb, Gr) using the equations (1) to (4), each pixel has a specific wavelength range (at least one wavelength range near 420 nm and 550 nm). Sensitivity increases.

  The second pre-processing circuit 220b2 performs the same signal processing as the first pre-processing circuit 220b1 on the mixed signal (Wr, Gb, Wb, Gr) after the sensitivity increase in the specific wavelength region, and after color interpolation. A signal is output to the matrix circuit 220c, and a luminance signal (Y) is generated from the mixed signals (Wr, Gb, Wb, Gr) and output to the image signal processing circuit 220d. The matrix circuit 220c performs a predetermined color matrix operation on the input color-interpolated signal. In the color matrix calculation, the signal after color interpolation input from the second pre-processing circuit 220b2 is multiplied by a color matrix coefficient (second coefficient different from the first coefficient) suitable for a spectroscopic image of a specific anatomy. Thus, the primary color signals (R, G, B) are converted. The converted primary color signals (R, G, B) are input to the image signal processing circuit 220d. The image signal processing circuit 220d converts the color difference signals (RY, BY) generated from the luminance signal Y and the primary color signals (R, G, B) into predetermined video signals. By sequentially inputting the converted video signals to the monitor 300, a spectral image that emphasizes a specific biological tissue of the subject is displayed on the display screen of the monitor 300.

  FIG. 8A schematically shows the blood vessel structure in the vicinity of the surface layer and in the deep layer. 8B and 8C illustrate spectral images displayed on the display screen of the monitor 300. FIG.

  Consider a case where the sensitivity in the wavelength region near 420 nm in each pixel is increased by the luminance generation processing by the second pre-stage processing circuit 220b2. In this case, the pixel in which the blood vessel structure in the vicinity of the surface layer is reflected remains dark because the information on absorption by hemoglobin is dominant. On the other hand, pixels in which other structures (for example, mucous membrane structures) are reflected become brighter because the luminance increases with an increase in sensitivity. As a result, the contrast between the pixel (dark part) in which the blood vessel structure in the vicinity of the surface layer is reflected and the pixel (bright part) in which the mucosal structure is reflected (see FIG. 8B) is improved.

  Consider a case where the sensitivity in the wavelength region near 550 nm in each pixel is increased by the luminance generation processing by the second pre-stage processing circuit 220b2. In this case, the pixels in which the deep blood vessel structure is shown remain dark because the information of absorption by hemoglobin is dominant. On the other hand, pixels in which other structures (for example, mucous membrane structures) are reflected become brighter because the luminance increases with an increase in sensitivity. As a result, the contrast between the pixel (dark part) in which the deep blood vessel structure appears and the pixel (bright part) in which the mucous membrane structure or the like appears is improved (see FIG. 8C). In the spectral image example of FIG. 8C, a certain degree of sensitivity is secured even in the wavelength region near 420 nm, so that the blood vessel structure near the surface layer is shown with low contrast.

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present application also includes an embodiment that is exemplarily specified in the specification or a combination of obvious embodiments and the like as appropriate.

  As a modification, consider a case where the color array of the solid-state image sensor 108 is a Bayer type (primary color system). In this case, the second pre-processing circuit 220b2 generates luminance that improves the contrast between the specific biological structure and the other structure in the spectroscopic image. For example, in each pixel, for example, B (Blue) light, Increase the sensitivity in the wavelength range close to the specific wavelength range. Thereby, the effect similar to this embodiment is acquired.

1 Electronic Endoscope System 100 Electronic Scope 200 Processor

Claims (6)

A luminance value acquisition means for acquiring a luminance value of a pixel of interest in a pixel group having a predetermined color arrangement;
The luminance value acquisition means includes
By calculating a signal of the pixel of interest using a signal of a pixel having a peak sensitivity in a specific wavelength region for emphasizing a specific biological structure among peripheral pixels located around the pixel of interest, the pixel of interest Increasing the sensitivity of the specific wavelength region, and obtaining the luminance value of the pixel of interest using a signal with increased sensitivity of the specific wavelength region,
Processor. The specific wavelength range is a wavelength range where the absorption of hemoglobin is large.
The processor of claim 1. A light source that emits light including a visible light region;
An optical filter that filters the irradiation light emitted from the light source into narrowband light corresponding to the specific wavelength range;
With
The luminance value acquisition means includes
A signal of each pixel constituting the pixel group having the predetermined color arrangement is input from a predetermined external device that images the subject irradiated with the narrowband light.
The processor according to claim 1 or 2. Optical filter switching means for inserting or retracting the optical filter with respect to the irradiation light path of the light source;
An operation means for accepting an input operation by a user;
With
The optical filter switching means is
The optical filter is inserted into the irradiation light path or retracted from the irradiation light path according to the input operation received by the operation means.
The processor according to claim 3. The luminance value acquisition means includes
During the period in which the optical filter is retracted from the irradiation optical path, the luminance value of the pixel of interest in the pixel group is acquired without performing the process of increasing the sensitivity,
During the period in which the optical filter is inserted in the irradiation optical path, the luminance value of the pixel of interest in the pixel group is acquired after performing the process of increasing the sensitivity.
The processor according to claim 4. Matrix calculation means for performing matrix calculation on the signal of each pixel,
The matrix calculation means includes
While the optical filter is retracted from the irradiation optical path, matrix calculation is performed using the first matrix coefficient, and during the period when the optical filter is inserted into the irradiation optical path, the first matrix coefficient is different. Perform matrix operations using the second matrix coefficients,
The processor according to claim 4 or 5.

Images