JP2013013589A - Image signal processor, imaging system, and electronic endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image signal processor suitable to display narrowband light images having various kinds of specific structures included in an observation visual field on a display screen of a monitor without additionally providing a narrowband light filter.SOLUTION: This image signal processor includes: an image signal input means to which an image signal from an imaging device having photographed a photographic object irradiated with prescribed narrowband light is input; a display mode designation means designating a display mode of the photographed photographic object from a plurality of kinds of display modes; a color matrix coefficient storage means storing a plurality of kinds of color matrix coefficients corresponding to the respective display modes; and an image generation means acquiring the color matrix coefficient corresponding to the designated display mode from the color matrix coefficient storage means, performing color conversion processing to the image signal, and generating the image of the photographed photographic object.

Description

  The present invention relates to an image signal processing apparatus that processes an image signal so that it can be displayed on a monitor. Specifically, the present invention is suitable for displaying narrowband light images of various specific structures included in an observation visual field on a display screen of a monitor. The present invention relates to an image signal processing device, an imaging system, and an electronic endoscope system.

  In the medical device field, an electronic endoscope system is known that generates and displays an enhanced image (narrowband light image) of a specific part in a body cavity by irradiating the body cavity with narrowband light. A specific configuration example of this type of electronic endoscope system is described in Patent Document 1.

  The electronic endoscope system described in Patent Document 1 has a rotary filter in which two types of filter sets corresponding to the frame sequential method are arranged. In the circumferential direction (outer peripheral side) of the rotary filter, the first filter filters the white light emitted from the light source into a surface-sequential light having spectral characteristics in which the respective filter lights overlap so as to be suitable for natural color reproduction. A filter set is arranged. In the circumferential direction (inner circumferential side) of the rotary filter, a second filter that filters white light emitted from the light source into surface-sequential light having discrete and narrow-band spectral characteristics from which deep tissue information can be extracted. A set is arranged.

  The first and second filter sets are alternatively arranged in the illumination optical path according to a predetermined mode switching operation. When the filter group arranged in the illumination optical path is switched, the color reproducibility changes with the change in the spectral characteristics of the illumination light. In the electronic endoscope system described in Patent Document 1, color conversion processing is performed using a dedicated color matrix coefficient corresponding to each filter set in order to suppress a change in color reproducibility when the filter set is switched. It is configured.

JP 2002-34908 A

  However, in the electronic endoscope system described in Patent Document 1, color conversion processing is performed using a fixed value (color matrix coefficient) for each filter set, so that a predetermined living body is displayed on the display screen of the monitor. Only narrowband light images specific to the structure are displayed. Therefore, the surgeon may overlook other important biological information.

  An image signal processing apparatus according to an aspect of the present invention that solves the above-described problem is captured by an image signal input unit that inputs an image signal from an imaging apparatus that captures a subject irradiated with a predetermined narrowband light. Display mode specification means for specifying the display mode of the subject from a plurality of display modes, color matrix coefficient storage means for storing a plurality of types of color matrix coefficients corresponding to each display mode, and correspondence to the specified display mode An image generation unit that obtains a color matrix coefficient to be obtained from a color matrix coefficient storage unit, performs a color conversion process on the image signal, and generates an image of a photographed subject.

  According to the image signal processing device of the present invention, even when one type of specific narrow-band light is irradiated on the subject, various types of identification included in the observation field of view can be performed by appropriately switching a plurality of types of display modes. A narrow-band optical image having a structure can be displayed on the display screen of the monitor. Therefore, oversight of important biological information by the surgeon can be suitably prevented.

  The image signal processing apparatus according to the present invention may include a narrowband light irradiating unit that irradiates a subject with predetermined narrowband light through a light guide included in the imaging apparatus. That is, the image signal processing device may be configured such that the two devices of the light source device and the image signal processing device are integrated.

  The narrow-band light irradiating means may be configured to selectively irradiate a subject with a plurality of types of narrow-band light having different spectral characteristics through a light guide. The color matrix coefficient storage means may store color matrix coefficients corresponding to each of a plurality of types of display modes separately associated with each narrowband light. In this case, the image generation means acquires from the color matrix coefficient storage means a color matrix coefficient corresponding to the designated display mode among a plurality of types of display modes associated with the narrowband light currently irradiated on the subject. Alternatively, the image signal may be subjected to color conversion processing to generate a photographed subject image.

  The narrow-band light irradiating means includes any one of a light source that emits predetermined broadband light, a plurality of types of narrow-band optical filters that split the broadband light into narrow-band light having different spectral characteristics, and a plurality of types of narrow-band optical filters. It is also possible to have a configuration having filter designating means for designating one of them and filter placement means for placing the designated narrowband optical filter in the optical path of the broadband light.

  An imaging system according to an aspect of the present invention that solves the above problems includes a narrowband light irradiating unit that irradiates a subject with predetermined narrowband light, a photographing unit that photographs a subject irradiated with the narrowband light, and photographing. Display mode designating means for designating the display mode of the subject selected from a plurality of types of display modes, a color matrix coefficient storage means for storing a plurality of types of color matrix coefficients corresponding to each display mode, and the designated display mode A color matrix coefficient corresponding to the image signal is obtained from the color matrix coefficient storage means, color conversion processing is performed on the image signal, and an image generation means for generating a photographed subject image is provided. is there.

  In addition, an electronic endoscope system according to an embodiment of the present invention that solves the above-described problems is a system including the image signal processing device and an electronic endoscope that is a predetermined imaging device.

  An electronic endoscope system according to another aspect of the present invention that solves the above problems is an embodiment of the imaging system, and includes narrowband light irradiation means, display mode designation means, color matrix coefficient storage means, And a processor having an image generating means and an electronic endoscope having a photographing means.

  According to the present invention, even when one type of specific narrow-band light is irradiated on the subject, various types of narrow-band optical images included in the observation field of view can be selected by appropriately switching a plurality of types of display modes. Are provided on a display screen of a monitor. An image signal processing apparatus, an imaging system, and an electronic endoscope system are provided.

It is a block diagram which shows the structure of the electronic endoscope system which concerns on embodiment of this invention. It is a figure which shows the structure of the rotary filter turret mounted in the processor which the electronic endoscope system which concerns on embodiment of this invention has. It is a figure which shows the spectral characteristic of each optical filter of the rotary filter turret which concerns on embodiment of this invention. It is a figure which shows the flowchart of the endoscopic image observation process which concerns on embodiment of this invention. It is a figure which illustrates notionally the color conversion process by the color conversion circuit mounted in the processor which concerns on embodiment of this invention. It is a figure for demonstrating that the specific structure of the biological body highlighted on the display screen of a monitor changes with switching of a display mode in embodiment of this invention.

  Hereinafter, an electronic endoscope system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration of an electronic endoscope system 1 according to the present embodiment. As shown in FIG. 1, the electronic endoscope system 1 is a medical imaging system, and includes an electronic scope 100, a processor 200, and a monitor 300. The proximal end of the electronic scope 100 is connected to the processor 200. The processor 200 integrally includes an image signal processing device that processes an image signal output from the electronic scope 100 to generate an image, and a light source device that illuminates a body cavity that does not reach natural light via the electronic scope 100. It is. In another embodiment, the image signal processing device and the light source device may be configured separately.

  As illustrated in FIG. 1, the processor 200 includes a system controller 202 and a timing controller 204. The system controller 202 controls each element constituting the electronic endoscope system 1. The timing controller 204 outputs a clock pulse for adjusting the signal processing timing to each circuit in the electronic endoscope system 1.

  The lamp 208 radiates light in a wavelength range mainly extending from the visible light region to the invisible infrared region after being started by the lamp power igniter 206. As the lamp 208, a high-intensity lamp such as a xenon lamp, a halogen lamp, a mercury lamp, or a metal halide lamp is suitable. The illumination light emitted from the lamp 208 is condensed by the condenser lens 210 and is limited to an appropriate amount of light through the diaphragm 212.

  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 diaphragm 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, and the amount of illumination light emitted from the lamp 208 is changed to the opening degree. Limit accordingly. The appropriate reference for the brightness of the image is changed according to the brightness adjustment operation performed by the operator on the front panel 218 or the hand operation unit (not shown) of the electronic scope 100.

  Various forms of the configuration of the front panel 218 are assumed. As a specific configuration example of the front panel 218, 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, and the like are assumed. .

  Irradiation light that has passed through the aperture 212 enters the rotary filter turret 213. FIG. 2 is a diagram showing a configuration of the rotary filter turret 213. As shown in FIG. 2, the rotary filter turret 213 has a plurality of optical filters F1 to F3 and an aperture AP arranged in the circumferential direction. The aperture AP is an aperture to which no optical filter is attached. The aperture AP may be replaced with a filter that transmits light in the entire visible light region.

  FIG. 3 shows an example of the spectral characteristics of the optical filters F1 to F3. In FIG. 3, the vertical axis represents spectral transmittance (no unit because it is normalized), and the horizontal axis represents wavelength (unit: nm). As shown in FIG. 3, the optical filter F1 is a narrow-band optical filter having a transmission peak with a narrow half-value width in three wavelength regions. The optical filter F2 is, for example, a narrow band optical filter having a transmission peak with a narrow half-value width in a wavelength range suitable for absorption of hemoglobin. The optical filter F3 is a narrow-band optical filter having a transmission peak with a narrow half-value width in a wavelength range corresponding to a specific structure (for example, a gastric duct structure or the like) different from the optical filter F2. Each narrow-band optical filter has, for example, detection (a filter with spectral characteristics suitable for finding a lesion from a wide range in a body cavity) and a probe (spectrum characteristics suitable for examining a found lesion). Etc.) may be provided for each application.

  The motor 215 is a step motor that is driven, for example, under the drive control of the driver 216, and is mechanically coupled to the rotary filter turret 213 via a transmission mechanism such as an arm or a gear (not shown). The motor 215 rotates the rotary filter turret 213 by an angle corresponding to the applied voltage (pulse).

  The surgeon can rotate the rotary filter turret 213 through the filter switching operation on the front panel 218 or the operation of the filter switching button 114 installed in the hand operation unit of the electronic scope 100. In FIG. 1, the connection between the filter switching button 114 (and the display mode switching button 116 described later) and other blocks is omitted to simplify the drawing.

  The rotary filter turret 213 rotates 90 ° each time a filter switching operation is performed, and is arranged by selectively inserting the optical filters F1, F2, F3, and the aperture AP into the illumination optical path. In the vicinity of the outer peripheral edge of the rotary filter turret 213, a position detection hole H for detecting the home position is formed.

  Based on the detection of the position detection hole H through the photo interrupter FI and the number of pulses applied to the motor 215, the system controller 202 recognizes which optical filter or aperture AP is inserted and arranged in the illumination optical path.

  The irradiation light is split into specific narrowband light by an optical filter (any one of F1 to F3) arranged in the illumination optical path, and enters an incident end of an LCB (Light Carrying Bundle) 102. When the aperture AP is disposed in the illumination optical path, the irradiation light that has passed through the stop 212 (that is, broadband light including the visible light region) is directly incident on the incident end of the LCB 102.

  Irradiation light incident on the incident end of the LCB 102 propagates by repeating total reflection in the LCB 102. Irradiation light propagating through the LCB 102 is emitted from the emission end of the LCB 102 disposed at the tip of the electronic scope 100. Irradiation light emitted from the exit end of the LCB 102 irradiates the subject via the light distribution lens 104. The reflected 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.

  The solid-state image sensor 108 is, for example, 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 an image signal corresponding to each complementary color of yellow Ye, cyan Cy, green G, and magenta Mg. .

  The solid-state imaging device 108 generates and outputs mixed signals Wr, Gb, Wb, and Gr by adding image signals of two pixels adjacent in the vertical direction in order to substantially improve sensitivity and frame rate. The mixed signals Wr, Gb, Wb, and Gr are input to the endoscope side signal processing circuit 112 after being amplified 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 timing controller 204 supplies clock pulses to the endoscope side signal processing circuit 112 according to the timing control by the system controller 202. The endoscope side signal processing circuit 112 controls driving of the solid-state imaging device 108 at a timing synchronized with a frame rate of a video processed on the processor 200 side, according to a clock pulse supplied from the timing controller 204.

  The image signal input to the endoscope side signal processing circuit 112 is subjected to AD conversion after predetermined analog signal processing and input to the processor side signal processing circuit 220.

  The processor-side signal processing circuit 220 includes a color conversion circuit 222, a memory 224, and an image processing circuit 226. The color conversion circuit 222 converts an image signal (complementary color signal (MGYC)) input to the processor side signal processing circuit 220 into a primary color signal (RGB) using a predetermined color matrix coefficient stored in the memory 224, and performs image processing. Output to the circuit 226. The image processing circuit 226 performs predetermined image processing such as γ correction and edge enhancement on the input primary color signal, and buffers each color signal in a frame memory (not shown) corresponding to each color of R, G, and B for each frame. Ring. The image processing circuit 226 sweeps out each buffered color signal from the frame memory at a timing controlled by the timing controller 204 and conforms to a predetermined standard such as NTSC (National Television System Committee) or PAL (Phase Alternating Line). Convert to video signal. By sequentially inputting the converted video signals to the monitor 300, the image of the subject is displayed on the display screen of the monitor 300.

  An image of the subject is displayed on the display screen of the monitor 300 in a form corresponding to the display mode, for example. The display mode is changed according to the display mode setting operation performed on the front panel 218 by the surgeon or the operation of the display mode switching button 116 installed on the hand operation unit of the electronic scope 100.

  The surgeon can set various different display modes for each optical filter inserted and arranged in the illumination optical path. Specifically, the surgeon selects n (two or more) types of display modes for highlighting different specific structures corresponding to the spectral characteristics of the optical filter F1 during the period in which the optical filter F1 is arranged in the illumination optical path. Can be set. During the period in which the optical filter F2 is arranged in the illumination optical path, m (two or more) types of display modes for highlighting different specific structures corresponding to the spectral characteristics of the optical filter F2 can be selected and set. During the period when the optical filter F3 is arranged in the illumination optical path, l (two or more) types of display modes for highlighting different specific structures corresponding to the spectral characteristics of the optical filter F3 can be selected and set.

  The memory 224 stores color matrix coefficients corresponding to each of a plurality of types of display modes associated with the optical filters F1 to F3. For convenience of explanation, symbols M11 to M1n are attached to n kinds of color matrix coefficients associated with each display mode related to the optical filter F1, and m kinds of color matrices associated with each display mode related to the optical filter F2. The coefficients M21 to M2m are attached to the coefficients, and the codes M31 to M31 are attached to l kinds of color matrix coefficients associated with the respective display modes related to the optical filter F3.

(Endoscopic image observation processing)
FIG. 4 shows a flowchart of endoscopic image observation processing according to the embodiment of the present invention. In the endoscopic image observation process of the present embodiment, the subject is displayed as a normal color image or in a form corresponding to the display mode. Execution of the endoscope image observation process is started when the electronic endoscope system 1 is activated or when a filter switching operation is performed on the front panel 218 or the filter switching button 114. If a filter switching operation is performed during the execution of the endoscopic image observation process, the endoscopic image observation process is forcibly returned to the process of S1. For convenience of explanation, the processing step is abbreviated as “S” in the explanation and drawings in this specification.

<S1 in FIG. 4 (Filter Determination Processing)>
The system controller 202 recognizes which optical filter or aperture AP is inserted and arranged in the illumination optical path based on the detection of the position detection hole H through the photo interrupter FI and the number of pulses applied to the motor 215. Note that when the electronic endoscope system 1 is activated, the aperture AP is inserted into the illumination optical path. Specifically, the system controller 202 detects the position detection hole H by rotating the rotary filter turret 213 through drive control with respect to the motor 215 when the system is started, and the opening AP is inserted into the illumination optical path. Thus, the rotary filter turret 213 is rotated by a predetermined angle from the detection position of the hole H.

  When the aperture AP is disposed in the illumination optical path (S1: aperture AP), the system controller 202 advances the process to S2. If any of the optical filters F1 to F3 is disposed in the illumination optical path (S1: optical filter), the process proceeds to S3.

<S2 in FIG. 4 (Normal Color Image Generation Processing)>
Since the aperture AP is disposed in the illumination optical path, the subject is irradiated with broadband light including a visible light region. The solid-state image sensor 108 receives reflected light from the subject irradiated with broadband light and converts it into an image signal. The image signal is output to the monitor 300 through signal processing in each of the preamplifier 110, the endoscope side signal processing circuit 112, and the processor side signal processing circuit 220. As a result, a normal color image of the subject is displayed on the display screen of the monitor 300, and the processing of this flowchart ends. The display of a normal color image on the display screen continues until, for example, the system of the electronic endoscope system 1 is stopped or a filter switching operation is performed.

<S3 in FIG. 4 (Narrowband Optical Image Generation Processing)>
Since any one of the optical filters F1 to F3 is arranged in the illumination optical path (hereinafter, for convenience of explanation, the optical filter currently arranged in the illumination optical path is referred to as “optical path arrangement filter”), the optical path arrangement is applied to the subject. Narrow band light corresponding to the spectral characteristics of the filter is irradiated. The solid-state image sensor 108 receives the reflected light from the subject irradiated with the narrow-band light and converts it into an image signal. The image signal is output to the monitor 300 through signal processing in each circuit of the preamplifier 110, the endoscope side signal processing circuit 112, and the processor side signal processing circuit 220.

  Here, the color conversion circuit 222 is a color matrix coefficient specified by an optical path arrangement filter and a currently set display mode (referred to as “set display mode” for convenience) in accordance with a predetermined control signal from the system controller 202. Are selected from the group of color matrix coefficients in the memory 224, and color conversion processing is performed using the selected color matrix coefficients. Therefore, a narrowband light image of the subject corresponding to the setting display mode is displayed on the display screen of the monitor 300. Note that immediately after the system activation of the electronic endoscope system 1 or immediately after the filter switching operation, the default display mode corresponding to the initial or switched optical path arrangement filter becomes the setting display mode.

  For example, consider a case where the optical path arrangement filter is the optical filter F1. In this case, the color conversion circuit 222 stores the color matrix coefficient corresponding to the setting display mode in the memory 224 from among the color matrix coefficients M11 to M1n associated with the optical filter F1 in accordance with a predetermined control signal from the system controller 202. Are selected from the group of color matrix coefficients, and color conversion processing is performed using them.

  Here, FIGS. 5A and 5B are conceptual diagrams of color conversion processing by the color conversion circuit 222. FIG. The left diagram in FIG. 5A shows the intensity distribution P of the mixed signals Wr, Gb, Wb, Gr, and the central diagram in FIG. 5A shows the optical filter of the rotary filter turret 213 arranged in the illumination optical path. The spectral characteristic F of the optical filter F1 (here, the optical filter F1) is shown, and the right figure of FIG. 8A shows the color matrix coefficient M (4 × 3) used in the color conversion processing by the color conversion circuit 222. In the left figure of Fig.5 (a), a vertical axis | shaft shows intensity | strength (because it is normalized and there is no unit), and a horizontal axis | shaft shows a wavelength (unit: nm). In the central diagram of FIG. 5A, the vertical axis indicates the spectral transmittance (no unit because it is normalized), and the horizontal axis indicates the wavelength (unit: nm). The intensity distribution P is a wavelength and intensity calculated when spectral characteristics corresponding to two pixels adjacent to each other in the vertical direction of the on-chip color filter of the solid-state image sensor 108 are applied to a two-pixel addition processing formula. It is a distribution showing the relationship.

  FIG. 5B shows an intensity distribution P ′ indicating the relationship between the wavelength and the intensity obtained as a result of multiplying the intensity distribution P, the spectral characteristic F, and the color matrix coefficient M of FIG. In FIG. 5B, the vertical axis represents intensity (no unit because it is normalized), and the horizontal axis represents wavelength (unit: nm).

  In the present embodiment, the intensity distribution P ′ is changed by changing at least one of the spectral characteristic F and the color matrix coefficient M shown in FIG. 5A, and the living body highlighted on the display screen of the monitor 300 is displayed. Change the specific structure. The color matrix coefficient M shown in FIG. 5A is changed by switching the color matrix coefficient (in other words, the display mode) applied in the color conversion processing by the color conversion circuit 222.

<S4 in FIG. 4 (Display Mode Switching Standby Process)>
The system controller 202 waits for execution of a display mode switching operation on the front panel 218 or the display mode switching button 116. During standby, for example, the display of the narrow-band light image corresponding to the setting display mode (S3 in FIG. 4) is continued. When the display mode switching operation is performed (S4: YES), the system controller 202 advances the process to S5.

<S5 in FIG. 4 (Narrowband Optical Image Generation Processing After Switching Display Mode)>
The color conversion circuit 222 newly selects a color matrix coefficient specified by the optical path arrangement filter and the switched setting display mode from the color matrix coefficient group in the memory 224 in accordance with a predetermined control signal from the system controller 202. Then, color conversion processing is performed using the selected color matrix coefficient. Therefore, a narrowband light image of the subject corresponding to the setting display mode after switching is displayed on the display screen of the monitor 300. After the process of S5, the process of this flowchart returns to S4.

  The display of the narrow-band light image after the display mode switching on the display screen is continued until, for example, the system of the electronic endoscope system 1 is stopped or a filter switching operation or a display mode switching operation is performed.

  FIGS. 6A and 6B are diagrams for explaining that the specific structure of the living body highlighted on the display screen of the monitor 300 changes as the display mode is switched. As shown in FIG. 6A, the depth of irradiation light and the wavelength are in a proportional relationship. Since the depth of penetration becomes deeper as the wavelength of the irradiation light becomes longer, observation of the deep biological structure becomes possible.

  For example, consider a case where the optical path arrangement filter is the optical filter F1 and the setting display mode is switched. The color matrix coefficient M corresponding to the display mode before switching emphasizes the short wavelength component in the intensity distribution of the subject image obtained by multiplying the intensity distribution P and the spectral characteristic F (the spectral characteristic of the optical filter F1). Designed to. Therefore, an image (shallow layer A in FIG. 6B) that emphasizes a shallow subject image (here, a shallow blood vessel) is displayed on the display screen of the monitor 300. On the other hand, the color matrix coefficient M corresponding to the display mode after switching emphasizes the long wavelength component in the intensity distribution of the subject image obtained by multiplying the intensity distribution P and the spectral characteristic F (the spectral characteristic of the optical filter F1). Designed to be. Therefore, an image (deep layer B in FIG. 6B) in which a deep subject image (here, a deep blood vessel) is emphasized is displayed on the display screen of the monitor 300.

  That is, in the present embodiment, a plurality of types of display modes for highlighting different specific structures are associated with one type of optical filter that splits illumination light. The operator can observe various specific structures included in the observation visual field by switching the display mode. Therefore, oversight of important biological information can be suitably prevented.

  Further, the spectral characteristic F shown in FIG. 5A is changed by operating the front panel 218 or the filter switching button 114 to switch the optical path arrangement filter. That is, changing the specific structure of the living body highlighted on the display screen of the monitor 300 (changing the intensity distribution P ′) is also achieved by switching the optical path arrangement filter. For example, when observing a specific structure that is difficult to be highlighted with the spectral characteristics of the optical filter F1, the surgeon switches the optical path arrangement filter to the optical filter F2 or F3, and displays suitable for highlighting the specific structure. Set the mode. As a result, it is possible to display a narrowband light image having a specific structure that is difficult to highlight with the spectral characteristics of the optical filter F1 on the display screen of the monitor 300.

  The above is the description of the embodiment of the present invention. The present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. For example, the number of optical filters arranged in the illumination optical path, spectral characteristics, and the like are not limited to those of the present embodiment.

DESCRIPTION OF SYMBOLS 1 Electronic endoscope system 100 Electronic scope 200 Processor 220 Processor side signal processing circuit 222 Color conversion circuit 224 Memory 226 Image processing circuit 300 Monitor

Claims (9)

An image signal input means for inputting an image signal from an imaging device that images a subject irradiated with a predetermined narrowband light;
Display mode designating means for designating a display mode of the photographed subject from a plurality of display modes;
Color matrix coefficient storage means for storing a plurality of types of color matrix coefficients corresponding to each of the display modes;
Image generation means for obtaining a color matrix coefficient corresponding to the designated display mode from the color matrix coefficient storage means, performing color conversion processing on the image signal, and generating an image of the photographed subject; ,
An image signal processing apparatus comprising: The image signal processing apparatus according to claim 1, further comprising a narrowband light irradiating unit configured to irradiate the subject with the predetermined narrowband light through a light guide included in the imaging apparatus. The narrowband light irradiation means selectively irradiates the subject with a plurality of types of narrowband light having different spectral characteristics through the light guide,
The color matrix coefficient storage means stores color matrix coefficients corresponding to each of a plurality of types of display modes separately associated with each narrowband light,
The image generation unit acquires, from the color matrix coefficient storage unit, a color matrix coefficient corresponding to the designated display mode among a plurality of types of display modes associated with the narrowband light currently irradiated on the subject. The image signal processing apparatus according to claim 2, wherein color conversion processing is performed on the image signal to generate an image of the photographed subject. The narrow-band light irradiation means includes
A light source that emits predetermined broadband light;
A plurality of types of narrowband optical filters that split the broadband light into narrowband light having different spectral characteristics, and
Filter designating means for designating any one of the plurality of types of narrowband optical filters;
Filter placement means for placing the designated narrowband optical filter in the optical path of the broadband light;
The image signal processing apparatus according to claim 3, further comprising: Narrow-band light irradiation means for irradiating a subject with predetermined narrow-band light;
Photographing means for photographing the subject irradiated with the narrow-band light and generating an image signal;
Display mode designating means for designating a display mode of the photographed subject from a plurality of display modes;
Color matrix coefficient storage means for storing a plurality of types of color matrix coefficients corresponding to each of the display modes;
Image generation means for obtaining a color matrix coefficient corresponding to the designated display mode from the color matrix coefficient storage means, performing color conversion processing on the image signal, and generating an image of the photographed subject; ,
An imaging system comprising: The narrowband light irradiation means selectively irradiates the subject with a plurality of types of narrowband light each having different spectral characteristics,
The color matrix coefficient storage means stores color matrix coefficients corresponding to each of a plurality of types of display modes separately associated with each narrowband light,
The image generation unit acquires, from the color matrix coefficient storage unit, a color matrix coefficient corresponding to the designated display mode among a plurality of types of display modes associated with the narrowband light currently irradiated on the subject. 6. The imaging system according to claim 5, wherein color conversion processing is performed on the image signal to generate an image of the photographed subject. The narrow-band light irradiation means includes
A light source that emits predetermined broadband light;
A plurality of types of narrowband optical filters that split the broadband light into narrowband light having different spectral characteristics, and
Filter designating means for designating any one of the plurality of types of narrowband optical filters;
Filter placement means for placing the designated narrowband optical filter in the optical path of the broadband light;
The imaging system according to claim 6, further comprising: The image signal processing device according to any one of claims 1 to 4,
An electronic endoscope as the imaging device;
An electronic endoscope system comprising: The imaging system according to any one of claims 5 to 7,
A processor having the narrowband light irradiation means, the display mode designation means, the color matrix coefficient storage means, and the image generation means;
An electronic endoscope having the imaging means;
An electronic endoscope system comprising:

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