JP2013081709A - Endoscope system, processor device of endoscope system and image generating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance only the concavity and the convexity on living tissues such as surface microstructures, thickening or the like.SOLUTION: By irradiating a fluorescent material with excitation light EL from an excitation light source, the fluorescent material is excited and emits white light. A subject is irradiated with the white light W and blue narrow band light BN simultaneously. In the light intensity ratio between the blue narrow band light BN and the excitation light EL, the ratio of the blue narrow band light BN is made larger than that of the excitation light EL. Image light of reflected light from the subject is imaged using a color CCD and a surface enhanced image 68 is acquired. The surface enhanced image 58 is subjected to contrast adjustment to increase the brightness of the microstructures 70 and to decrease the brightness of the microscopic vessels 71 and the mucosal membrane 72 other than the microstructures 70. By doing so, a microstructure enhanced image 74 in which only the microstructures 70 are enhanced is acquired.

Description

  The present invention relates to an endoscope system capable of clearly observing a fine structure such as a pit pattern formed on a biological tissue and a concavo-convex pattern such as a thickening, a processor device of the endoscope system, and an image generation method.

  In recent medical treatments, diagnosis using an endoscope apparatus is widely performed. In this endoscopic diagnosis, in addition to normal light observation using broadband white light as illumination light in the subject, special light of a specific wavelength is used as illumination light, so that lesions such as cancer can be seen from other parts. In addition, special light observation that makes it easier to intuitively grasp the position and size of a lesion is also being performed.

  For example, in Patent Document 1, the depth of the living tissue in the depth direction and the light absorption characteristics of blood hemoglobin have wavelength dependency, and are formed on the surface of the living tissue with a short wavelength blue narrow band light. In addition to clarifying fine structures such as fine blood vessels and pit patterns, thick blood vessels located in the middle and deep layers of biological tissues are clarified with green narrow-band light having a longer wavelength than blue narrow-band light. These superficial-medium-deep blood vessels and superficial microstructures are important clues for cancer differentiation and depth diagnosis. Etc. can be improved dramatically.

  Further, in Patent Document 2, when the living tissue is irradiated with excitation light for exciting autofluorescence, autofluorescence from a lesion site thickened by a lesion such as a cancer is caused by autofluorescence from a normal site that is not thickened. By utilizing the characteristic that the amount of light is reduced compared to fluorescence, the boundary between the lesioned part and the normal part is clarified. By clarifying the boundary with the lesion site in this way, the position and size of the lesion site can be easily grasped when observing from a distant view as in screening.

Japanese Patent Laid-Open No. 2001-170009 JP-A-8-252218

  In recent years, there are a wide variety of methods for cancer discrimination and depth diagnosis. Therefore, in addition to performing cancer diagnosis from both blood vessel patterns such as superficial fine blood vessels and middle-deep blood vessels and concave / convex patterns such as superficial fine structures and thickening, there are also cases in which diagnosis is performed by paying attention only to the concave / convex patterns. In this way, when making a diagnosis by paying attention only to the concavo-convex pattern, it is necessary to improve the visibility of the concavo-convex pattern while reducing the visibility of the blood vessel pattern.

  Patent Document 1 does not describe or suggest the clarification of only the uneven pattern. Moreover, according to patent document 2, thickening can be clarified among uneven | corrugated patterns. However, since the autofluorescence used for the detection of thickening is weak, in order to capture this with high sensitivity, a high-sensitivity image sensor such as EMCCD is required separately.

  An object of the present invention is to provide an endoscope system, a processor device of the endoscope system, and an image generation method capable of clarifying only irregularities on a living tissue such as a surface fine structure and thickening.

  An endoscope system of the present invention emits a first semiconductor light source that emits first illumination light that is narrowed in a blue band, and second illumination light that has a wavelength range different from that of the first illumination light. Imaging a subject image by imaging a second semiconductor light source, a wavelength conversion member that excites and emits white light with the second illumination light, and a subject illuminated with the first illumination light and the white light. By adjusting the color characteristic value of the subject image in accordance with the light amount ratio between the first illumination light and the second illumination light, the object image generation means to be generated, and only the unevenness on the living tissue And a concavo-convex emphasis image generating means for generating an embossed concavo-convex emphasized image.

  When the ratio of the first illumination light is larger than the ratio of the second illumination light in the light amount ratio, the unevenness-enhanced image generation unit increases the contrast of the fine structure in the living tissue of the surface layer, while fine It is preferable to have a microstructure-enhanced image generation unit that generates a microstructure-enhanced image in which only the microstructure is enhanced by reducing contrast other than the structure. It is preferable that the fine structure-enhanced image generation unit specifies the fine structure and other positions based on the hue of the subject image.

  When the ratio of the first illumination light is smaller than the ratio of the second illumination light in the light amount ratio, the unevenness-enhanced image generation unit increases the contrast of the thickening of the living tissue in the middle depth, while thickening It is preferable to have a thickening enhanced image generation unit that generates a thickening enhanced image in which only the thickening is enhanced by lowering the contrast other than the above. It is preferable that the thickening emphasized image generation unit specifies thickening and other positions based on the hue of the subject image.

  Preferably, the first illumination light has a center wavelength of 405 nm, the second illumination light has a center wavelength of 445 nm, and the white light has a wavelength range of 460 to 700 nm. The wavelength conversion member is preferably a phosphor. It is preferable to include a display unit that displays the unevenness-enhanced image.

  In the present invention, the first illumination light narrowed in the blue band and the second illumination light having a wavelength range different from that of the first illumination light are applied to the wavelength conversion member to receive white light that is excited and emitted. In a processor device of an endoscope system connected to an electronic endoscope that illuminates a specimen and images the subject illuminated with the first illumination light and white light to obtain a subject image, the light amount It is characterized by comprising an unevenness-enhanced image generating means for generating an unevenness-enhanced image in which only the unevenness on the living tissue is enhanced by adjusting the color characteristic value of the subject image according to the ratio.

  In the image generation method of the present invention, excitation light is emitted by applying the first illumination light narrowed in the blue band and the second illumination light having a wavelength range different from that of the first illumination light to the wavelength conversion member. A subject image is illuminated by illuminating the subject with white light, and the subject illuminated with the first illumination light and the white light is imaged with an electronic endoscope, and the first illumination light and the first illumination light are obtained. By adjusting the color characteristic value of the subject image according to the light quantity ratio with respect to the illumination light of 2, the unevenness-enhanced image generating means that generates the unevenness-enhanced image in which only the unevenness on the living tissue is enhanced is generated. And

  According to the present invention, the unevenness-enhanced image obtained by the unevenness-enhanced image generating unit includes the first illumination light narrowed in the blue band and the second illumination light for exciting white light with the wavelength conversion member. Since this image is obtained by adjusting the color characteristic value of the subject image according to the light quantity ratio, only the unevenness on the living tissue such as the surface fine structure and thickening is clarified in this unevenness enhanced image. Yes.

It is a figure which shows an endoscope system. It is a figure which shows the internal structure of an endoscope system. It is a graph which shows the emission spectrum of the white light W at the time of normal observation mode. It is a graph which shows the emission spectrum of the white light W at the time of fine structure observation mode. It is a graph which shows the emission spectrum of the white light W at the time of thickening observation mode. It is a graph which shows the emission spectrum of the white light W at the time of fine structure and thickening observation mode. It is a figure which shows the image in a subject when a zoom lens exists in a wide position. It is a figure which shows the image in a subject when a zoom lens exists in a tele position. It is a graph which shows the spectral transmittance of the color filter of R color, G color, and B color. It is a figure for demonstrating the imaging control of CCD in the normal observation mode. It is a figure for demonstrating the imaging control of CCD in the fine structure observation mode, the thickening observation mode, and the fine structure / thickness observation mode. It is a figure which shows the internal structure of a special light image generation part. It is a figure for demonstrating the production | generation method of a fine structure emphasis image. It is a figure for demonstrating the production | generation method of a thickening emphasis image. It is a flowchart showing a series of flows in the fine structure observation mode.

  As shown in FIGS. 1 and 2, an endoscope system 10 includes an electronic endoscope 11 that captures an image of a subject, a processor device 12 that performs various image processing on an image captured by the electronic endoscope 11, and A light source device 13 that supplies light to illuminate the subject to the electronic endoscope 11 and a monitor 14 that displays an image subjected to various image processing by the processor device 12 are provided.

  The electronic endoscope 11 includes a flexible insertion portion 16 to be inserted into a subject, an operation portion 17 provided at a proximal end portion of the insertion portion 16, an operation portion 17, a processor device 12, and a light source device 13. And a universal cord 18 for connecting the two. A bending portion 19 in which a plurality of bending pieces are connected is formed at the distal end of the insertion portion 16. The bending portion 19 is bent in the vertical and horizontal directions by operating the angle knob 21 of the operation portion 17. At the distal end of the bending portion 19, a distal end portion 16a incorporating an optical system for in-vivo imaging is provided. The distal end portion 16 a is directed in a desired direction within the subject by the bending operation of the bending portion 19.

  Further, the operation unit 17 is provided with a mode switching SW 15 for switching to various modes. The mode includes a normal observation mode in which a normal light image obtained by imaging a subject illuminated with white light is displayed on the monitor 14 and a fine structure enhanced image in which the fine structure formed on the surface layer of the biological tissue is emphasized. Is displayed on the monitor 14, the thickening observation mode is displayed on the monitor 14, and the thickening observation mode is displayed with a thickening emphasis image that emphasizes the thickening from the surface layer to the middle depth layer in the living tissue. The structure / thickness weighted image is displayed on the monitor 14 and is composed of a total of three modes including a fine structure / thickness observation mode.

  A connector 24 is attached to the universal cord 18 on the processor device 12 and the light source device 13 side. The connector 24 is a composite type connector including a communication connector and a light source connector, and the electronic endoscope 11 is detachably connected to the processor device 12 and the light source device 13 via the connector 24.

  The light source device 13 includes a pumping light source 30 that emits pumping light EL having a specific wavelength, a blue narrowband light source 31 that emits blue narrowband light BN narrowed to a specific wavelength in the blue band, and a pumping light source 30. An optical fiber 32 for excitation light to which the excitation light EL is incident, an optical fiber 33 for blue narrow band light to which the blue narrow band light BN from the blue narrow band light source 31 is incident, these optical fibers 32 and 33, and an electronic endoscope. A coupler 35 for optically connecting the light guide 43, a light source switching unit 36 for switching the excitation light source 30 and the blue narrow band light source 31 on and off, and the excitation light source 30 and the blue narrow band light source 31. The light quantity control part 37 which adjusts the light quantity is provided.

The excitation light source 30 is composed of a semiconductor light source such as a laser diode, and emits excitation light EL having a central wavelength of 445 nm (see FIGS. 3A to 3D). The excitation light EL is applied to the phosphor 40 provided at the distal end portion 16 a of the electronic endoscope 11 through the excitation light optical fiber 32, the coupler 35, and the light guide 43. In the phosphor 40, a plurality of types of fluorescent materials (for example, YAG-based fluorescent materials or BAM (BaMgAl ₁₀ O ₁₇ )) that absorb a part of the excitation light EL and excite and emit green to red (460 to 700 nm) fluorescence FL. Etc.). The fluorescence FL excited and emitted by the phosphor 40 is combined with the excitation light EL that is transmitted without being absorbed by the phosphor 40, thereby generating white light W (see FIGS. 3A to 3D). Since the white light W has a large depth from the surface layer to the mid-deep layer, it is used for detecting thickening and the like.

  The blue narrow band light source 31 is composed of a semiconductor light source such as a laser diode, and emits blue narrow band light BN having a center wavelength of 405 nm (see FIGS. 3A to 3D). Since this blue narrow-band light BN has a depth of penetration to the surface layer of the living tissue, it is used to brighten the surface microvessels and microstructures in the surface layer of the living tissue.

  The light source switching unit 36 is connected to a controller 59 in the processor device, and switches the excitation light source 30 and the blue narrow band light source 31 ON (lit) and OFF (dark) according to the set mode. When the normal observation mode is set, the excitation light source 30 is always turned on, while the blue narrow band light source 31 is always turned off. Therefore, only the white light W is always irradiated to the subject. On the other hand, when the fine structure observation mode, the thickening observation mode, or the fine structure / thickness observation mode is set, both the excitation light source 30 and the blue narrow band light source 31 are always turned on. Thereby, both the white light W and the blue narrow-band light BN are irradiated to the subject.

  The light quantity control unit 37 is connected to a controller 59 in the processor device, and adjusts the light quantities of the excitation light source 30 and the blue narrow band light source 31 according to the set mode. When the normal observation mode is set, the excitation light EL is adjusted to the light amount ELc as shown in FIG. 3A. In modes other than the normal observation mode, the light amounts of the excitation light EL and the blue narrow band light BN are adjusted based on the light amount ELc. When the fine structure observation mode is set, as shown in FIG. 3B, the light amount of the entire white light W is reduced by adjusting the excitation light EL to a light amount ELs smaller than the light amount ELc. On the other hand, the blue narrow band light BN is adjusted to a light quantity BNs that is larger than the light quantity ELc. That is, the ratio of the blue narrow band light BN is adjusted to be higher in the light quantity ratio between the excitation light EL and the blue narrow band light BN.

  When the thickening observation mode is set, as shown in FIG. 3C, the light amount of the entire white light W is increased by adjusting the excitation light EL to a light amount ELd larger than the light amount ELc. On the other hand, the blue narrow band light BN is adjusted to a light amount BNd smaller than the light amount ELc. That is, the ratio of the excitation light EL is adjusted to be higher in the light amount ratio between the excitation light EL and the blue narrow band light BN. When the fine structure / thickness observation mode is set, as shown in FIG. 3D, the excitation light EL is adjusted to a light amount ELb larger than the light amount ELc to increase the light amount of the entire white light W and The narrow band light BN is also adjusted to a light quantity BNb larger than the light quantity ELc. Further, when adjusting the light amount, the respective light amounts are adjusted so that the light amount ratio between the excitation light EL and the blue narrow-band light BN is 1: 1.

  As shown in FIG. 2, the electronic endoscope 11 includes a light guide 43, a CCD 44, an analog processing circuit 45 (AFE: Analog Front End), an imaging control unit 46, and a magnification control unit 47. The light guide 43 is a large-diameter optical fiber, a bundle fiber, or the like. The incident end is inserted into the coupler 35 in the light source device, and the emission end is directed to the phosphor 40. The light guided in the light guide 43 is irradiated into the subject through the phosphor 40, the zoom lens 48a, the irradiation lens 48b, and the illumination window 49.

  An actuator 48c for moving the zoom lens 48a in the optical axis direction is attached to the zoom lens 48a. The actuator 48 c is driven and controlled by a magnification control unit 47 connected to the controller 59. The magnification control unit 47 controls the actuator 48c so that the zoom lens 48a moves to a position corresponding to the magnification set by the zoom operation unit 20. When it is necessary to observe the entire state in the subject as in screening, the zoom lens 48a is set to the wide position, and a non-enlarged image as shown in FIG. On the other hand, when it is necessary to observe the detailed structure of the observation site as in the differential diagnosis of cancer, the zoom lens 48a is set at the tele position, and an enlarged image as shown in FIG. .

  In the normal observation mode and the thickening observation mode, the entire state in the subject is often observed, so the zoom lens 48a is often set at a wide position. On the other hand, in the fine structure observation mode, since the observation target is often enlarged and observed, the zoom lens 48a is often set at the tele position.

  As shown in FIG. 2, the observation window 50 receives the return light from the subject. The received light is incident on the CCD 44 through the condenser lens 51. The CCD 44 has an imaging surface 44a on which the light from the condenser lens 51 is incident. The CCD 44 photoelectrically converts the light received by the imaging surface 44a and accumulates signal charges. The accumulated signal charge is read as an imaging signal and sent to the AFE 45. The CCD 44 is a color CCD, and on the imaging surface 44a, there are 3 pixels: a B pixel provided with a B color filter, a G pixel provided with a G color filter, and an R pixel provided with an R color filter. Color pixels are arranged. These color filters of B color, G color, and R color have spectral transmittances indicated by curves 52, 53, and 54 shown in FIG.

  The AFE 45 includes a correlated double sampling circuit (CDS), an automatic gain control circuit (AGC), and an analog / digital converter (A / D) (all not shown). The CDS performs correlated double sampling processing on the image pickup signal from the CCD 44 to remove noise generated by driving the CCD 44. The AGC amplifies the imaging signal from which noise has been removed by CDS. The A / D converts the imaging signal amplified by the AGC into a digital imaging signal having a predetermined number of bits and inputs the digital imaging signal to the processor device 12.

  The imaging control unit 46 is connected to a controller 59 in the processor device 12, and sends a drive signal to the CCD 44 when an instruction is given from the controller 59. The CCD 44 outputs an imaging signal to the AFE 45 at a predetermined frame rate based on the drive signal from the imaging control unit 46.

  When the normal observation mode is set, as shown in FIG. 6A, a step of photoelectrically converting the image light of the white light W and accumulating signal charges within one frame period, and reading out the accumulated signal charges Steps are performed. This imaging control is repeatedly performed while the normal observation mode is set. In this mode, a blue signal Bc, a green signal Gc, and a red signal Rc are output from the B pixel, G pixel, and R pixel of the CCD 44, respectively.

  On the other hand, when the fine structure observation mode, the thickening observation mode, and the fine structure / thickness mode are set, as shown in FIG. 6B, the image light of the white light W and the blue narrow band light BN within one frame period. Are photoelectrically converted to accumulate signal charges and read as accumulated signal charges. This imaging control is repeatedly performed while the fine structure observation mode, the thickening observation mode, and the fine structure / thickening mode are set.

  In the fine structure observation mode, a blue signal Bs, a green signal Gs, and a red signal Rs are output from the B pixel, the G pixel, and the R pixel of the CCD 44, respectively. In the thickening observation mode, a blue signal Bd, a green signal Gd, and a red signal Rd are output from the B pixel, G pixel, and R pixel of the CCD 44, respectively. In the fine structure / thickness observation mode, a blue signal Bb, a green signal Gb, and a red signal Rb are output from the B pixel, G pixel, and R pixel of the CCD 44, respectively.

  As shown in FIG. 2, the processor device 12 includes a normal light image generation unit 55, a frame memory 56, a special light image generation unit 57, and a display control circuit 58. The controller 59 controls each unit. Yes. The normal light image generation unit 55 generates a normal light image from the signals Bc, Gc, and Rc obtained by capturing the image light of the white light W with the electronic endoscope 11. The generated normal light image is temporarily stored in the frame memory 56.

  As shown in FIG. 7, the special light image generation unit 57 includes a fine structure emphasized image generation unit 61, a thickening emphasized image generation unit 62, and a fine structure / enhanced image generation unit 63. The microstructure-enhanced image generation unit 61 includes an image generation unit 61a that generates a surface-layer-enhanced image that emphasizes a surface-layer microstructure that includes a pit pattern or the like in which a large number of micropores formed on the surface of a biological tissue are collected, A contrast adjustment unit 61b that adjusts the contrast of the image to generate a microstructure-enhanced image in which only the surface layer microstructure is enhanced.

  The image generation unit 61a generates a surface layer emphasized image based on the signals Bs, Gs, and Rs acquired in the fine structure observation mode. The signal Bs contains more blue narrowband light BN components than white light W components. The blue narrow-band light BN brightens the pit pattern by causing white light or blue narrow-band light BN to enter the micro holes of the pit pattern and causing a multiple scattering phenomenon. Therefore, the pixel value of the fine structure region having the pit pattern is extremely high. Further, the blue narrow band light BN has a depth of penetration to the surface of the living tissue, and is included in a wavelength region where the absorption coefficient of hemoglobin is high. For this reason, in the surface-enhanced image, the pixel value of the region where the surface layer microvessel is present is smaller than the other regions.

  The contrast adjusting unit 61b adjusts the contrast of the surface enhanced image in order to highlight the fine structure in the surface enhanced image. In contrast adjustment, first, the surface-enhanced image is converted into a color space of hue, saturation, and brightness. In the surface layer enhanced image 68 after color space conversion, as shown in FIG. 8A, the hue of the fine structure 70 is a value corresponding to white, and the hue of the fine blood vessel 71 is a value corresponding to a blackish color. Thus, the hue of the mucous membrane 72 other than the fine structure 70 and the fine blood vessel 71 has a value corresponding to a bluish color.

  From these hues, the positions of the fine structure 70, the fine blood vessel 71, and the mucous membrane 72 in the surface enhanced image 68 are specified. When those positions are specified, the brightness of the fine structure 70 is increased, while the brightness of the microvessel 71 and the mucous membrane 72 is decreased. As a result, as shown in FIG. 8B, a fine structure-enhanced image 74 in which the fine structure 70 is highlighted and the display of the fine blood vessels 71 and the mucous membrane 72 is suppressed is obtained. The fine structure emphasized image 74 is displayed on the monitor 14 by the display control circuit 58 after being converted from a color space to an RGB image. Although the contrast adjustment unit 61b improves the contrast of the fine structure by increasing or decreasing the lightness, the fine structure and other contrast may be adjusted according to various color characteristic values other than the lightness.

  As described above, in the fine structure observation mode, the fine structure 70 is displayed in white, the fine blood vessel 71 is displayed in a blackish color, and the mucous membrane 72 is displayed in a blueish color. This is because of the following reasons. The light irradiated to the subject in the fine structure observation mode contains a large amount of blue narrow band light BN, and thus is bluish white light. When this bluish white light is illuminated, in a fine structure such as a pit pattern, the light that has entered the fine hole causes a multiple scattering phenomenon to shine white. Therefore, the fine structure is displayed in white. In addition, since the fine blood vessel exhibits high light absorption characteristics with respect to light in the blue band, the amount of light reflected by the fine blood vessel is reduced. Therefore, the fine blood vessels are displayed in a blackish color. On the other hand, since the mucous membrane is simply reflected, it is displayed with a bluish tint.

  The thickening emphasized image generation unit 62 generates an intermediate deep layer emphasized image in which a thickened portion from the surface layer to the intermediate deep layer is emphasized by a portion raised from the biological tissue surface layer, and an intermediate deep layer emphasized image contrast. And a contrast adjustment unit 62b for adjustment.

  The image generation unit 62a generates an intermediate deep layer emphasized image based on the signals Bd, Gd, Rd acquired in the thickening observation mode. The signals Gd and Rd contain more white light components than the blue narrow band light BN. When the thickened portion is irradiated with the white light W, the amount of light reflected from the thickened portion is lower than that of the non-thickened portion. Therefore, the pixel value of the region with thickening is low. Further, since the white light W has a depth of penetration to the middle and deep layers of the living tissue, when there are blood vessels in the middle and deep layers, the pixel value of the blood vessels is even lower than the thickened region. It has become. From the above, in the mid-depth image, the pixel values are lower in the order of the non-thickened region, the thickened region, and the blood vessel region.

  The contrast adjustment unit 62b adjusts the contrast of the intermediate deep layer emphasized image in order to highlight the thickening in the intermediate deep layer emphasized image. When adjusting the contrast, first, similarly to the contrast adjusting unit 61b, the mid-depth image is converted into a color space of hue, saturation, and brightness. In the intermediate deep layer emphasized image 78 after the color space conversion, as shown in FIG. 9A, the hue of the thickening 80 becomes a value corresponding to the grayish color, and the hue of the intermediate deep blood vessel 81 is blackish. It becomes a value corresponding to the color, and the hue of the mucous membrane 82 other than the thickening 80 and the intermediate deep blood vessel 81 becomes a value corresponding to a yellowish color.

  From these hues, the positions of the thickening 80, the intermediate deep blood vessel 81, and the mucous membrane 82 in the intermediate deep layer emphasized image 78 are specified. Once these positions are identified, the brightness of the thickening 80 is increased while the brightness of the mid-deep blood vessel 81 and the mucous membrane 82 is decreased. As a result, as shown in FIG. 9B, a thickening enhanced image 84 in which the thickening 80 is highlighted and the display of the middle-deep blood vessels 81 and the mucous membrane 82 is suppressed is obtained. The thickening emphasized image 84 is converted from a color space to an RGB image and then displayed on the monitor 14 by the display control circuit 58. In the contrast adjustment unit 62b, the contrast of the thickening is improved by increasing or decreasing the brightness. However, the fine structure and other contrast may be adjusted according to various color characteristic values other than the brightness.

  As described above, in the thickening observation mode, the thickening 80 is displayed in gray, the mid-deep blood vessel 81 is displayed in blackish color, and the mucous membrane 82 is displayed in yellowish color. Because of the reason. The light irradiated to the subject in the thickening observation mode contains a lot of fluorescent FL components among the components of white light W, and thus becomes yellowish white light. When this yellowish white light is illuminated, the thickening 80 is displayed in gray because the amount of reflected light is reduced. Similarly, the mid-deep blood vessel 81 has a characteristic that the amount of reflected light is further reduced than that of the thickening, and is therefore displayed in a blackish color. In contrast, the mucous membrane 82 is displayed in a yellowish color because the amount of reflected light does not fall.

  Based on the signals Bb, Gb, and Rb acquired in the fine structure / thickness observation mode, the fine structure / thickness emphasized image generation unit 63 generates a fine structure / thickness emphasized image in which the thickening is emphasized together with the fine structure. The generated fine structure / thickening weighted image is displayed on the monitor 14 by the display control circuit 58. The signal Bb includes a component of the blue narrow band light BN having a light amount ELb larger than the light amount ELc in the normal observation mode, and the signals Gb and Rb include white light having a light amount larger than that in the normal observation mode. W component is included. Therefore, in the fine structure / thickening weighted image, the pixel value of the fine structure area with the pit pattern is extremely high, while the thickened area is low, so the fine structure and thickened part are emphasized respectively. It is displayed.

  Next, a series of flows in the fine structure observation mode will be described using the flowchart shown in FIG. Note that a series of flows in the thickening observation mode and the fine structure / thickness observation mode are substantially the same, and thus the description thereof is omitted.

  When switched to the fine structure observation mode by the mode switching SW 15, the blue narrow-band light source 31 is turned on in addition to the excitation light source 30 that is already turned on. The excitation light EL is set to a light amount ELs smaller than the light amount ELc in the normal observation mode, and the light amount of the blue narrow band light BN is set to ELs larger than the light amount ELc. The excitation light EL and the blue narrow-band light BN with the light amount set are irradiated onto the phosphor 40 via the light guide 43 and the like. In the phosphor 40, the white light W is emitted by the excitation light EL, while the blue narrow band light BN is transmitted as it is. The white light W and the blue narrow band light BN that have passed through the phosphor 40 are simultaneously irradiated toward the subject. The subject illuminated by the white light and the blue narrow-band light BN is imaged by the color CCD 44, whereby the blue signal Bs, the green signal Gs, and the red signal Rs are output from the CCD 44.

  Next, a surface-emphasized image is generated based on the blue signal Bs, the green signal Gs, and the red signal Rs. In the surface enhanced image, the blue narrow band light BN enters the fine holes of the pit pattern and the multiple scattering phenomenon occurs, so that the pit pattern is displayed brightly. On the other hand, in the blue narrow band light BN, the fine blood vessels on the surface layer are highlighted. Therefore, in the surface-enhanced image, not only the fine structure such as the pit pattern but also the fine blood vessels in the surface layer are clarified.

  Next, contrast adjustment is performed to highlight only the fine structure in the surface layer emphasized image. First, the surface-enhanced image is converted into a color space of hue, saturation, and brightness, and the positions of the fine structure, fine blood vessel, and mucous membrane are specified from the hue value. Once their location is specified, the brightness of the microstructure is increased while the brightness of the microvessels and mucous membranes is decreased. As a result, a fine structure emphasized image in which only the fine structure 70 is highlighted is obtained. The fine structure emphasized image is converted from a color space to an RGB image and then displayed on the monitor 14 by the display control circuit 58.

DESCRIPTION OF SYMBOLS 10 Endoscope system 32 Excitation light source 33 Blue narrow-band light source 40 Phosphor 61 Fine structure emphasis image generation part 61a, 62a Image generation part 62 Thickening emphasis image generation part 61b, 62b Contrast adjustment part 74 Fine structure emphasis image 84 Thickness emphasis image

Claims (10)

A first semiconductor light source that emits first illumination light narrowed in the blue band;
A second semiconductor light source that emits second illumination light having a wavelength range different from that of the first illumination light;
A wavelength conversion member that excites white light by the second illumination light; and
Subject image generation means for generating a subject image by imaging the subject illuminated with the first illumination light and the white light;
Concavities and convexities that generate a concavity and convexity-enhanced image that emphasizes only the concavities and convexities on the living tissue by adjusting the color characteristic value of the subject image according to the light quantity ratio between the first illumination light and the second illumination light. An endoscopic system comprising: an enhanced image generation unit. The unevenness-enhanced image generating unit
In the light amount ratio, when the ratio of the first illumination light is larger than the ratio of the second illumination light, by increasing the contrast of the fine structure in the living tissue of the surface layer, by reducing the contrast other than the fine structure The endoscope system according to claim 1, further comprising a fine structure emphasized image generation unit that generates a fine structure emphasized image in which only the fine structure is emphasized.   The endoscope system according to claim 2, wherein the microstructure-enhanced image generation unit identifies the microstructure and other positions based on the hue of the subject image. The unevenness-enhanced image generating unit
In the light amount ratio, when the ratio of the first illumination light is smaller than the ratio of the second illumination light, by increasing the contrast of the thickening of the living tissue in the middle depth layer, by reducing the contrast other than the thickening, The endoscope system according to claim 1, further comprising a thickening emphasized image generation unit that generates a thickening emphasized image in which only the thickening is emphasized.   The endoscope system according to claim 4, wherein the thickening weighted image generation unit identifies thickening and other positions based on a hue of the subject image.   The center wavelength of the first illumination light is 405 nm, the center wavelength of the second illumination light is 445 nm, and the white light has a wavelength range of 460 to 700 nm. The endoscope system according to any one of 1 to 5.   The endoscope system according to claim 1, wherein the wavelength conversion member is a phosphor.   The endoscope system according to claim 1, further comprising display means for displaying the unevenness-enhanced image. The subject is illuminated with white light that is excited and emitted by applying the first illumination light narrowed in the blue band and the second illumination light having a wavelength range different from that of the first illumination light to the wavelength conversion member. In addition, in the processor device of the endoscope system connected to the electronic endoscope that images the subject illuminated with the first illumination light and the white light and obtains the subject image,
Intraocular enhancement image generating means for generating an unevenness-enhanced image generating means for generating an unevenness-enhanced image in which only unevenness on a biological tissue is enhanced by adjusting a color characteristic value of the subject image according to the light amount ratio Mirror system processor unit. The subject is illuminated with white light that is excited and emitted by applying the first illumination light narrowed in the blue band and the second illumination light having a wavelength range different from that of the first illumination light to the wavelength conversion member. ,
Acquiring a subject image by imaging the subject illuminated with the first illumination light and the white light with an electronic endoscope;
By adjusting the color characteristic value of the subject image in accordance with the light quantity ratio between the first illumination light and the second illumination light, the unevenness-enhanced image obtained by enhancing only the unevenness on the living tissue An image generation method, characterized by being generated by a generation means.

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