JP2016192986A - Endoscope system and operation method of endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope system capable of performing magnification observation of an observation object stably, and an operation method of the endoscope system.SOLUTION: An endoscope system 10 includes a light source 36 for emitting illumination light, an image capturing sensor 48 for capturing an image of an observation object to which the illumination light is irradiated, a freeze button 22b for inputting a still image acquisition instruction for giving an instruction to acquire a still image of the observation object, a control unit 71 for inserting a still image capturing frame for acquiring an image signal for a still image for creating a still image by magnifying the observation object by an electronic zoom between moving image capturing frames for acquiring an image signal for a moving image that forms a moving image of the observation object when the still image acquisition instruction is input, a moving image creation unit 63 for creating the moving image of the observation object using the image signal for a moving image, and a magnified still image creation unit 64 for creating a magnified still image which is a still image magnifying the observation object by the electronic zoom using the image signal for a still image.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an endoscope system for enlarging and observing an observation target in a subject, and a method for operating the endoscope system.

  In the medical field, diagnosis is generally performed using an endoscope system including an endoscope, a light source device, and a processor device. The endoscope has an insertion portion that is inserted into the subject, and images an observation target (such as a mucous membrane in the subject) irradiated with illumination light generated by the light source device. The processor device generates an image of the observation target using an image signal obtained by imaging the observation target, and displays the image on the monitor.

  In addition, it has a function of magnifying and observing an observation target by optical zoom or electronic zoom (also called digital zoom), and displays a moving image of the observation target and a still image obtained by magnifying the observation target simultaneously on the monitor. Endoscopic systems are known. For example, the endoscope system of Patent Document 1 displays a moving image of an observation target that is not enlarged (hereinafter referred to as a non-enlarged moving image) and a still image obtained by enlarging the observation target by optical zoom on a monitor. The endoscope system of Patent Literature 2 displays a non-enlarged moving image to be observed and a still image obtained by enlarging the observation object by electronic zoom on a monitor. And the endoscope system of patent document 3 is displaying the moving image which expanded the observation object by the optical zoom, and the still image of the observation object which is not expanded on the monitor.

JP2013-240522A JP 2008-229205 A JP 2010-124921 A

  Since the observation target of the endoscope system is the mucous membrane of the digestive tract and the like, it continuously moves by the peristaltic motion, and the relative positional relationship between the distal end of the insertion portion of the endoscope and the observation target continues to change. When the observation target is enlarged by optical zoom or electronic zoom, the apparent relative movement between the endoscope and the observation target becomes more intense. For this reason, the observation target may be lost during magnified observation. Even if the observing object is not lost, it is difficult to keep observing the observing object stably and stably because the movement of the observing object rotates in the screen.

  As mentioned above, it is difficult to keep observing an enlarged observation target with a movie, so it may be observed by taking a still image. Naturally, it is not easy to capture a lesion or the like in a still image when the object is moving around.

  An object of the present invention is to provide an endoscope system capable of stably magnifying and observing an observation target, and an operation method of the endoscope system.

  An endoscope system of the present invention includes a light source that emits illumination light, an imaging sensor that captures an observation target irradiated with the illumination light, and a still image that inputs a still image acquisition instruction that instructs acquisition of a still image of the observation target. When an acquisition instruction unit and a still image acquisition instruction are input, a still image in which the observation target is enlarged by electronic zoom is generated between the moving image capturing frames that acquire the moving image signal that forms the observation target moving image. A control unit for inserting a still image pickup frame for acquiring a still image signal to be generated, a moving image generation unit for generating a moving image to be observed using the moving image signal, and an observation target using the still image signal An enlarged still image generating unit that generates an enlarged still image that is a still image enlarged by electronic zoom.

  The control unit preferably makes the shutter speed of the still image capturing frame faster than the shutter speed of the moving image capturing frame.

  The control unit preferably makes the amount of illumination light of the enlarged still image capturing frame larger than the amount of illumination light of the moving image capturing frame.

  The control unit preferably inserts a plurality of still image pickup frames between the moving image pickup frames in response to one input of a still image acquisition instruction.

  The enlarged still image generating unit generates a plurality of enlarged still images using a plurality of still image signals acquired with a plurality of still image capturing frames, and expands the input for one still image acquisition instruction. It is preferable to update the display of the still image a plurality of times.

  The enlarged still image generation unit includes a noise reduction unit that performs noise reduction processing using a plurality of still image signals acquired by a plurality of still image pickup frames, and uses the still image signal that has been subjected to noise reduction processing. It is preferable to generate an enlarged still image.

  The enlarged still image generation unit is equipped with a super-resolution processing unit that performs super-resolution processing using a plurality of still image signals acquired with a plurality of still image capture frames. It is preferable to generate an enlarged still image using an image signal.

  The enlarged still image generation unit preferably includes an image signal selection unit that compares a plurality of still image signals and selects a plurality of still image signals with less blur among the plurality of still image signals. .

  The enlarged still image generating unit includes an enlarged region setting unit that sets an area to be enlarged by electronic zoom using a moving image signal or a still image signal, and an enlarged still image obtained by enlarging the region set by the enlarged region setting unit It is preferable to generate a stroke.

  The enlarged still image generating unit includes a feature point detecting unit that detects a feature point of an observation target using a moving image signal or a still image signal, and the enlarged region setting unit is a feature detected by the feature point detecting unit. It is preferable to set a region to be enlarged by electronic zoom using points.

  The feature point detection unit may detect a plurality of feature points, and the enlargement area setting unit may set an area where the feature point selected from the plurality of feature points is located in the center as an area to be enlarged by electronic zoom. preferable.

  The operation method of the endoscope system of the present invention inputs a light source that emits illumination light, an image sensor that images an observation target irradiated with the illumination light, and a still image acquisition instruction that instructs acquisition of a still image of the observation target In the operation method of the endoscope system having a still image acquisition instruction unit, the control unit acquires a moving image signal that forms a moving image to be observed when a still image acquisition instruction is input A step of inserting a still image pickup frame for acquiring a still image signal for generating a still image obtained by enlarging an observation target by electronic zoom between the image pickup frames, and a moving image generation unit using the moving image signal A step of generating a moving image to be observed, and a step of generating an enlarged still image that is a still image obtained by enlarging the observation target by electronic zoom using the still image signal. .

  According to the endoscope system and the operation method of the endoscope system of the present invention, when a still image acquisition instruction is input, a still image capturing frame is inserted between moving image capturing frames. Using an image signal, a still image (hereinafter referred to as an enlarged still image) is generated by enlarging the observation target with electronic zoom, so there is no need to take a still image after enlarging the observation target, allowing stable observation from a distant view By simply inputting a still image acquisition instruction in a state where the target is captured, it is possible to automatically generate an enlarged still image that accurately captures a lesion or the like.

It is an external view of an endoscope system. It is a block diagram of an endoscope system. It is explanatory drawing which shows the imaging frame for moving images which acquires the image signal for moving images. It is a display screen of the monitor which displays a moving image. It is explanatory drawing which shows the imaging frame at the time of inputting a still image acquisition instruction. It is a timing chart which shows shutter speed, exposure time, and the light quantity of illumination light. It is a display screen of a monitor that displays an enlarged still image to be observed. It is a flowchart which shows operation | movement of an endoscope system. It is explanatory drawing of the modification which inserts multiple imaging frames for still images. It is explanatory drawing in the case of updating an enlarged still image. It is a block diagram of the expansion still picture generation part which performs noise reduction processing. It is a block diagram of the expansion still picture generation part which performs super-resolution processing. It is a block diagram of the expansion still image generation part which selects the image signal for still images used for noise reduction processing. It is a block diagram of the expansion still image generation part which tracks the location to expand. It is explanatory drawing which shows a feature point and the area | region to expand. It is the schematic of a capsule endoscope.

  As shown in FIG. 1, the endoscope system 10 includes an endoscope 12, a light source device 14, a processor device 16, a monitor 18, and a console 20. The endoscope 12 is optically connected to the light source device 14 and electrically connected to the processor device 16 by the universal cord 17. The endoscope 12 includes an insertion portion 21 to be inserted into a subject, an operation portion 22 provided at a proximal end portion of the insertion portion 21, a bending portion 23 and a distal end portion provided at the distal end side of the insertion portion 21. 24. By operating the angle knob 22a of the operation unit 22, the bending unit 23 performs a bending operation. By this bending operation, the distal end portion 24 can be directed in a desired direction.

  The operation unit 22 is provided with a freeze button 22b and the like in addition to the angle knob 22a. The freeze button 22b functions as a still image acquisition instruction unit for inputting a still image acquisition instruction for instructing acquisition of a still image to be observed. The endoscope system 10 displays a non-enlarged moving image to be observed on the monitor 18 unless a still image acquisition instruction is input. When a still image acquisition instruction is input by the freeze button 22b, an enlarged still image that is a still image to be observed and a part of the observation target is enlarged and a non-magnified moving image to be observed are displayed on the monitor 18. indicate. The freeze button 22b also functions as a display switching unit that stops the display of the enlarged still image and returns the display of the monitor 18 to only the non-enlarged moving image to be observed, as before the input of the still image acquisition instruction. In this case, the freeze button 22b inputs a display switching instruction.

  The processor device 16 is electrically connected to the monitor 18 and the console 20. The monitor 18 displays non-magnified moving images to be observed and enlarged still images to be observed, as well as information on these moving images. The console 20 functions as a user interface that receives input operations such as function settings. The processor device 16 may be connected to a recording unit (not shown) or the like that records a non-enlarged moving image to be observed, an enlarged still image, information attached thereto, and the like.

  As shown in FIG. 2, the light source device 14 includes a light source 36 that generates illumination light to be irradiated on the observation target, and a light source control unit 37 that controls the light source 36. The light source 36 includes, for example, a plurality of color LEDs (Light Emitting Diodes) such as a purple LED, a blue LED, a green LED, and a red LED, and an optical filter that limits a wavelength band of light emitted from these LEDs. The light source control unit 37 controls the lighting timing and light emission amount of the LEDs constituting the light source 36, the insertion and removal of the optical filter, and the like. For example, the light source 36 generates white light as illumination light, and generates blue light (blue narrow band light) or green light (green narrow band light) having a narrower wavelength band than white light depending on the setting. In the present embodiment, the light source 36 generates white light as illumination light. In the present embodiment, the light source 36 is configured by a plurality of colors of LEDs, optical filters, and the like as described above. Instead, a broadband light source such as a xenon lamp or a white LED, and a wavelength band of light emitted from the broadband light source. The light source 36 can also be configured by an optical filter that limits the above. Further, instead of the LED, the light source 36 can be configured by combining an LD (Laser Diode), a phosphor that emits fluorescence by laser light emitted from the LD, and an optical filter that restricts the wavelength band of the laser light or fluorescence. .

  Illumination light emitted from the light source 36 enters the light guide 41 via an optical member (all not shown) such as a condenser lens, an optical fiber, or a multiplexer. The light guide 41 is built in the universal cord 17 and the endoscope 12. The light guide 41 propagates illumination light to the distal end portion 24 of the endoscope 12. A multimode fiber can be used as the light guide 41. As an example, a thin fiber cable having a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter of φ0.3 to 0.5 mm including a protective layer serving as an outer shell can be used.

  The distal end portion 24 of the endoscope 12 has an illumination unit 26 and an imaging unit 27. An illumination lens 45 is provided in the illumination unit 26, and illumination light emitted from the light guide 41 is irradiated to the observation target via the illumination lens 45.

  The imaging unit 27 includes an imaging lens 47 and an imaging sensor 48. The imaging lens 47 causes light from an observation target such as fluorescence emitted from the observation target to be incident on the imaging sensor 48 by reflected light of illumination light or irradiation of the illumination light, and the imaging sensor 48 images the observation target.

  The image sensor 48 is a color image sensor, images an observation target, and outputs an image signal. As the imaging sensor 48, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor can be used. The imaging sensor 48 has RGB pixels provided with RGB color filters on the imaging surface, and outputs image signals of RGB colors by performing photoelectric conversion on the RGB pixels. As the image sensor 48, a so-called complementary color image sensor having C (cyan), M (magenta), Y (yellow), and G (green) complementary color filters on the imaging surface may be used. When a complementary color imaging sensor is used as the imaging sensor 48, any of the endoscope 12, the light source device 14, and the processor device 16 is used as a color conversion unit that performs color conversion from four CMYG image signals to three RGB image signals. You should set it up. In this way, even when a complementary color image sensor is used, it is possible to obtain RGB three-color image signals by color conversion from the four-color CMYG image signals.

  The image sensor 48 can change the speed of the electronic shutter (hereinafter referred to as shutter speed) and the length of the exposure time, the gain applied when the image signal is output, and the like at least for each image frame. The imaging frame is a unit of time in which the imaging sensor 48 images the observation target and outputs one set of image signals necessary for generating one image. In the present embodiment, R image signals, G image signals, and B image signals corresponding to RGB color filters are used to generate one frame of non-enlarged moving image or one enlarged still image. This is a set of image signals. For this reason, the time for the imaging sensor 48 to image the observation target and acquire one set of image signals is one imaging frame.

  The imaging frame includes a moving image imaging frame and a still image imaging frame, and the difference between these is imaging conditions. The moving image imaging frame is an imaging frame in which the imaging sensor 48 captures an observation target under a moving image capturing condition and acquires a moving image signal suitable for generating a non-enlarged moving image to be observed. The still image capturing frame is an image capturing frame in which the imaging sensor 48 captures an observation target under the still image capturing condition and acquires a still image signal suitable for generating an enlarged still image of the observation target. The imaging conditions include, for example, the amount of illumination light applied to the observation target, the shutter speed and exposure time of the electronic shutter of the imaging sensor 48, the gain applied when the image signal is output, and the illumination light applied to the observation target. Includes light intensity. In this embodiment, when the imaging conditions of the moving image capturing frame and the still image capturing frame are compared, the still image capturing frame has a higher shutter speed, shorter exposure time, and illumination than the moving image capturing frame. Increase the amount of light.

  Each color image signal output from the image sensor 48 is transmitted to a CDS (correlated double sampling) / AGC (automatic gain control) circuit 50. The CDS / AGC circuit 50 performs correlated double sampling (CDS) and automatic gain control (AGC) on the analog image signal output from the image sensor 48. The image signal that has passed through the CDS / AGC circuit 50 is converted into a digital image signal by the A / D converter 52. The digitized image signal is input to the processor device 16.

  The processor device 16 includes an image signal acquisition unit 54, an image processing unit 62, a display image signal generation unit 68, and a control unit 71. The image signal acquisition unit 54 acquires an image signal from the endoscope 12. The image signal acquisition unit 54 includes a DSP (Digital Signal Processor) 56, a noise reduction unit 58, and a signal conversion unit 59.

  The DSP 56 performs various signal processing such as defect correction processing, offset processing, gain correction processing, linear matrix processing, gamma conversion processing, demosaic processing, and YC conversion processing on the acquired image signal. In the defect correction process, the signal of the defective pixel of the image sensor is corrected. In the offset process, the dark current component is removed from the image signal subjected to the defect correction process, and an accurate zero level is set. In the gain correction processing, the signal level of each image signal is adjusted by multiplying each RGB image signal subjected to the offset processing by a specific gain. The image signal of each color subjected to the gain correction process is subjected to linear matrix processing for improving color reproducibility. Thereafter, the brightness and saturation of each image signal are adjusted by gamma conversion processing. A demosaic process (also referred to as an isotropic process or a synchronization process) is performed on the image signal subjected to the linear matrix process, and a color signal with missing pixels is generated by interpolation. Through the demosaic processing, all pixels have signals of RGB colors. The DSP 59 performs YC conversion processing on each demodulated image signal, and outputs the luminance signal Y, the color difference signal Cb, and the color difference signal Cr to the noise reduction unit 58.

  The noise reduction unit 58 performs noise reduction processing by, for example, a moving average method or a median filter method on the image signal subjected to demosaic processing or the like by the DSP 56. The image signal with reduced noise is input to the signal conversion unit 59, reconverted into an RGB image signal, and input to the image processing unit 62.

  The image processing unit 62 includes a moving image generation unit 63 and an enlarged still image generation unit 64. The moving image generation unit 63 generates a non-enlarged moving image to be observed using the moving image signal acquired in the moving image capturing frame. Specifically, the moving image generation unit 63 generates a set of RGB image signals to be acquired in the moving image capturing frame in order to generate an image for one frame of the non-enlarged moving image, respectively, as an R pixel, a G pixel, and a B pixel. RGB image data assigned to is generated. The generated RGB image data is further subjected to color conversion processing such as 3 × 3 matrix processing, gradation conversion processing, and three-dimensional lookup table processing. Next, various color enhancement processing is performed on the color-converted RGB image data, and structure enhancement processing such as spatial frequency enhancement is performed on the color enhancement RGB image data. The RGB image data subjected to structure enhancement processing is an image for one frame of a non-enlarged moving image.

  The enlarged still image generation unit 64 generates an enlarged still image using the still image signal acquired in the still image pickup frame. Similarly to the case where the moving image generating unit 63 generates an image for one frame of a non-enlarged moving image using one set of image signals acquired in the moving image capturing frame, the enlarged still image generating unit 64 includes the still image capturing frame. RGB image data is generated using a set of image signals acquired in the process, and color conversion processing and structure enhancement processing such as matrix processing, gradation conversion processing, and three-dimensional lookup table processing are performed on the generated RGB image data. Thus, a still image to be observed is generated. Then, a part of the generated still image is trimmed, and an enlarged still image to be observed is generated by electronic zoom that expands to the same size as the original still image. In the present embodiment, the area that the enlarged still image generation unit 64 enlarges by electronic zoom is the front of the imaging unit 27 (the center part of the non-enlarged moving image), but the area that the enlarged still image generation unit 64 enlarges by electronic zoom. Can be changed by setting or the like.

  The display image signal generation unit 68 converts the non-enlarged moving image generated by the moving image generation unit 63 and the expanded still image generated by the enlarged still image generation unit 64 into a display format signal (display image signal) and monitors it. 18 Thereby, the non-enlarged moving image and the enlarged still image to be observed are displayed on the monitor 18.

The control unit 71 comprehensively controls each unit of the endoscope system 10. For example, the control unit 71
The imaging sensor 48 is controlled to adjust the shutter speed and the length of the exposure time and the gain applied when outputting the image signal. In addition, the control unit 71 controls the light source control unit 37 to adjust the spectral spectrum and the light amount of the illumination light irradiated on the observation target. Then, the control unit 71 controls the monitor 18 to switch between a first display pattern for displaying the non-enlarged moving image to be observed and a second display pattern for displaying the enlarged still image to be observed and the non-enlarged moving image. do.

  The control unit 71 performs composite control of the image sensor 48, the light source control unit 37, and the monitor 18. For example, the control unit 71 repeatedly drives the imaging sensor 48 and the light source control unit 37 under the imaging conditions for moving images, thereby repeatedly executing a plurality of moving image capturing frames as illustrated in FIG. The acquisition unit 54 sequentially acquires moving image signal signals. FIG. 3 shows a state where moving image signals are acquired by moving image capturing frames for five frames “M1” to “M5”. Further, as shown in FIG. 4, the control unit 71 causes the monitor 18 to display an observation target non-enlarged moving image 91 generated by the moving image generating unit 63.

  On the other hand, when a still image acquisition instruction is input by the freeze button 22b, the control unit 71 inserts the still image pickup frame between the moving image pickup frames that are repeatedly executed as described above. For example, as illustrated in FIG. 5, when a still image acquisition instruction is input by the freeze button 22b during the execution of the moving image pickup frame M2, the control unit 71 sets the moving image pickup frame M2 and the moving image pickup frame M2 to The still image pickup frame F1 is inserted between the moving image pickup frame M3 to be executed next, and the image signal acquisition unit 54 acquires the still image signal. As described above, when the still image pickup frame F1 is inserted between the moving image pickup frame M2 and the moving image pickup frame M3, as illustrated in FIG. Compared with the image pickup frame M2 and the like, the shutter speed of the still image pickup frame F1 is increased to shorten the exposure time. Further, the control unit 71 controls the light source control unit 37 so that the amount of illumination light of the still image pickup frame F1 is larger than the amount of illumination light of the moving image pickup frame M2 or the like.

  Even when the still image pickup frame F1 is inserted as described above, the moving image generation unit 63 includes the moving image pickup frames M1 before and after the still image pickup frame F1 (for example, the moving image pickup frames M1 to M4 in FIG. 5). The generation of the non-enlarged moving image to be observed is continued using the moving image signal acquired at the same time. The enlarged still image generation unit 64 generates an enlarged still image to be observed using the still image signal acquired in the inserted still image pickup frame F1. That is, when the control unit 71 inserts a still image pickup frame between the moving image pickup frames M2 and M3 in response to an input of a still image acquisition instruction, a non-enlarged moving image and an enlarged still image to be observed are generated. . Therefore, for example, as illustrated in FIG. 7, the control unit 71 displays an enlarged still image 92 and a non-enlarged moving image 91 on the monitor 18. In addition, the control unit 71 displays a region 91 a corresponding to the enlarged still image 92 in the non-enlarged moving image 91 with, for example, a broken line.

  In FIG. 7, the enlarged still image 92 to be observed is displayed larger than the non-enlarged moving image 91, but these display sizes can be arbitrarily changed by setting or the like. In addition, when the monitor 18 has a plurality of display screens, for example, when the monitor 18 includes two displays, the enlarged still image 92 and the non-enlarged moving image 91 may be displayed on each of them.

  Next, the flow of the operation of the endoscope system 10 of the present embodiment will be described along the flowchart of FIG. When the endoscope system 10 is activated, the control unit 71 drives the image sensor 48 and the light source control unit 37 under moving image capturing conditions, and repeatedly executes moving image capturing frames (S11). Since the moving image generating unit 63 generates the non-enlarged moving image 91 to be observed using the moving image signal acquired by the moving image capturing frame M1 or the like, the control unit 71 includes the moving image generating unit 63 on the monitor 18. The non-enlarged moving image 91 to be generated is displayed (S12), and a still image acquisition instruction is awaited (S13; NO).

  When a still image acquisition instruction is input via the freeze button 22b (S13; YES), the control unit 71 inserts one still image pickup frame F1 between the moving image pickup frames (S14). In the still image pickup frame F1, the shutter speed of the image sensor 48 is faster and the exposure time is shorter than at least the preceding and subsequent moving image pickup frames M1 to M5. Further, the amount of illumination light is larger than that of the moving image pickup frames M1 to M5.

  When the control unit 71 inserts the still image pickup frame F1 between the moving image pickup frames M1 to M5 and the like, the moving image generation unit 63 uses the moving image signal acquired by the moving image pickup frames M1 to M5 to select the observation target. Since the non-enlarged moving image 91 is generated and the enlarged still image generating unit 64 generates the enlarged still image 92 to be observed using the still image signal acquired in the still image pickup frame F1, the control unit 71 The magnified still image 92 and the non-magnified moving image 91 to be observed are displayed on the monitor 18 (S15). The display of the enlarged still image 92 and the non-enlarged video 91 is input by the freeze button 22b in order to stop the display of the enlarged still image 92 by the freeze button 22b and return to the display of only the non-enlarged video 91. Continue until

  As described above, the endoscope system 10 has a still image pickup frame between the moving image pickup frames M1 to M5 and the like that are continuously and repeatedly executed when a still image acquisition instruction is input by the freeze button 22b. Since F1 is inserted and the enlarged still image 92 of the observation object is automatically generated and displayed, the observation object can be obtained by bringing the distal end portion 24 of the endoscope 12 close to the observation object or performing a zoom operation. There is no need to acquire a still image after zooming in. For this reason, according to the endoscope system 10, the still image is observed by the freeze button 22b in a state where the observation target is always observed from a distant view, and the portion to be magnified is stably captured at substantially the center of the non-magnified moving image 91. By simply inputting an acquisition instruction, an enlarged still image 92 that accurately captures a lesion or the like can be easily generated and displayed. Note that the endoscope system 10 does not use an optical zoom, and therefore does not require a zoom lens or the like. For this reason, the endoscope system 10 can be configured at low cost, and the insertion portion 21 of the endoscope 12 can be formed in a small diameter.

  Further, as described above, in the endoscope system 10, when the control unit 71 inserts the still image pickup frame F1 between the moving image pickup frames M1 to M5, the shutter speed of the still image pickup frame F1 is set. Then, the shutter speed of the moving image pickup frames M1 to M5 is set to be faster, and the exposure time of the still image pickup frame F1 is made shorter than the exposure time of the moving image pickup frames M1 to M5. This is to capture a moving still image of the observation object clearly and without blur. In particular, in an enlarged still image, even if there is slight blurring, it tends to become unclear due to enlargement. Therefore, the shutter speed of the still image pickup frame F1 is made faster and the exposure time is made shorter than the moving image pickup frames M1 to M5. As a result, a still image signal that can withstand the generation of the enlarged still image is obtained.

  Note that the moving image is a collection of still images, but the still image signal obtained by the still image pickup frame F1 is not suitable for moving images. For example, when a moving image is generated using a plurality of still image signals obtained by repeatedly executing the still image pickup frame F1, there is no smoothness, and it is difficult to observe and frame the moving image. Become. For this reason, in the endoscope system 10, the moving image signal suitable for the non-enlarged moving image 91 is generated by the moving image pickup frames M1 to M5 having the shutter speed slower than the still image pickup frame F1 and the exposure time being extended. It has gained.

  Furthermore, when the still image pickup frame F1 is inserted between the moving image pickup frames M1 to M5 and the like, the endoscope system 10 picks up still image pickup light more than the amount of illumination light of the moving image pickup frames M1 to M5. The amount of illumination light of the frame F1 is increased. This is an enlarged still image generated using the still image signal and the still image signal when the shutter speed of the still image capturing frame F1 is made faster than the moving image capturing frames M1 to M5 and the exposure time is shortened. This is because 92 becomes dark. By making the amount of illumination light of the still image pickup frame F1 larger than that of the moving image pickup frames M1 to M5, the brightness of the still image signal and the enlarged still image 92 is compensated to the same extent as the non-enlarged movie 91. A bright enlarged still image 92 can be generated and displayed.

  In the above-described embodiment, when a still image acquisition instruction is input by the freeze button 22b, a still image is captured between the moving image capturing frame M2 being executed when the still image acquisition instruction is input and the moving image capturing frame M3 to be executed next. Although the image pickup frame F1 is inserted, the insertion timing of the still image pickup frame F1 is within a range in which the input timing of the still image acquisition instruction and the acquisition timing of the still image signal can be grasped almost simultaneously. Is optional. For example, when a still image acquisition instruction is input during execution of the moving image pickup frame M2, a still image pickup frame is inserted between the moving image pickup frame M2 and the next moving image pickup frame M3 as in the above-described embodiment. Instead of inserting F1, a still image pickup frame F1 may be inserted between the moving image pickup frame M3 and the moving image pickup frame M4 to be executed next.

  In the above embodiment, one still image pickup frame F1 is inserted between the moving image pickup frames M1 to M5 and the like for one input of a still image acquisition instruction. A plurality of still image pickup frames may be inserted between moving image pickup frames that are repeatedly executed in response to an acquisition instruction. For example, as shown in FIG. 9, when a still image acquisition instruction is input during the execution of the moving image pickup frame M2, first, similarly to the above embodiment, the moving image pickup frame M2 and the moving image to be executed next to the moving image pickup frame M2 are executed. The first still image pickup frame F1 is inserted between the image pickup frame M3. Thereafter, a second still image pickup frame F2 is placed between the moving image pickup frame M10 executed after the moving image pickup frame M3 and the moving image pickup frame M11 executed next to the moving image pickup frame M10. insert.

  In FIG. 9, two still image capturing frames, a first still image capturing frame F1 and a second still image capturing frame F2, are inserted in response to one still image acquisition instruction. Three or more still image capturing frames may be inserted in response to a still image acquisition instruction. Also, the insertion timing of the first still image pickup frame F1, the second still image pickup frame F2, and the still image pickup frames inserted thereafter is arbitrary. Since the acquisition timing of the moving image signal becomes discrete by inserting the still image pickup frame F1 or the like, two or more still image pickup frames are continuous within a range in which the non-enlarged moving image 91 can be generated smoothly. May be.

  As described above, when a plurality of still image pickup frames F1 and F2 are inserted between the moving image pickup frames M1 to M11 in response to one still image acquisition instruction, the enlarged still image generation unit 64 An enlarged still image can be generated using the still image signal acquired in each of the still image pickup frames F1 and F2. For this reason, as shown in FIG. 10, the control unit 71 displays on the monitor 18 an enlarged still image 92 generated using the first still image signal acquired in the first still image pickup frame F1. After that, the enlarged still image 92 displayed on the monitor 18 is updated to the enlarged still image 101 generated using the second still image signal acquired in the second still image pickup frame F2. it can. That is, in response to a single still image acquisition instruction, a plurality of still image capturing frames F1 and F2 are inserted between the moving image capturing frames M1 to M11 and the like, and each still image capturing frame is acquired. If a plurality of enlarged still images 92 and 101 are generated using the still image signal to be generated, the display of the enlarged still image can be updated a plurality of times in response to one still image acquisition instruction. In response to a single still image acquisition instruction, still image pickup frames F1 and F2 and the like are inserted at regular intervals between moving image pickup frames M1 to M11 that are repeatedly executed. If an enlarged still image is generated using each acquired still image signal and the display of the enlarged still image on the monitor 18 is updated, the enlarged still image can be displayed like a low frame rate moving image.

  Further, when a plurality of still image pickup frames F1 and F2 are inserted between the moving image pickup frames M1 to M11 in response to a single still image acquisition instruction, a plurality of still image pickup frames F1 and F1 are inserted. Noise reduction processing can be performed using a plurality of still image signals acquired by F2 or the like, and an enlarged still image 92 with less noise can be generated and displayed using the still image signals subjected to noise reduction processing. . In this case, as shown in FIG. 11, the enlarged still image generation unit 64 includes a still image signal storage unit 111 that stores a plurality of still image signals, and a so-called cyclic noise reduction process (three-dimensional noise). A noise reduction unit 112 that performs a reduction process is also provided. Cyclic noise reduction processing reduces noise with low randomness and low correlation between frames, for example, by averaging a plurality of image signals that are acquired in a short period of time and have a small observation target movement and high correlation. It is processing. The enlarged still image generation unit 64 generates an enlarged still image 92 using the still image signal for which noise reduction processing has been performed by the noise reduction unit 112.

  When a plurality of still image pickup frames F1 and F2 are inserted between the moving image pickup frames M1 to M11 in response to a single still image acquisition instruction, a plurality of still image pickup frames are acquired. A still image 92 with a high resolution that is clear even when enlarged by electronic zoom using a still image signal that has been subjected to super-resolution processing using the still image signal of It can also be generated and displayed. In this case, as shown in FIG. 12, the enlarged still image generation unit 64 stores a still image signal storage unit 111 for storing a plurality of still image signals and a still image signal storage unit 111. A super-resolution processing unit 113 is provided that generates a still image signal with a higher resolution by performing super-resolution processing using a plurality of still image signals. In the super-resolution processing, for example, an interpolation image signal is generated by performing an interpolation operation between a plurality of image signals, and the generated interpolation image signal is weighted based on the edge strength or the like to obtain the original image signal. This is a process for obtaining a high-resolution image signal by combining (see, for example, Japanese Patent Application Laid-Open No. 2004-88616). The enlarged still image generating unit 64 generates an enlarged still image 92 using the still image signal for which the super-resolution processing by the super-resolution processing unit 113 is performed.

  As described above, when the enlarged still image 92 is generated by performing noise reduction processing or super-resolution processing, noise reduction processing among a plurality of still image signals stored in the still image signal storage unit 111 is performed. Further, by selecting the still image signal used for super-resolution processing, the result of noise reduction processing or super-resolution processing is improved, and an enlarged still image 92 with particularly good image quality may be obtained.

  Therefore, when the noise reduction unit 112 is provided in the enlarged still image generation unit 64, as shown in FIG. 13, the enlarged still image generation unit 64 includes a plurality of still image signals stored in the still image signal storage unit 111. It is preferable to further provide an image signal selection unit 114 that selects a still image signal used by the noise reduction unit 112 from the image signal. The image signal selection unit 114 compares a plurality of still image signals stored in the still image signal storage unit 111, and selects a plurality of still image signals that have a combination with less blur. The noise reduction unit 112 can generate a still image signal with particularly good image quality by performing noise reduction processing using a plurality of still image signals selected by the image signal selection unit 114.

  In FIG. 13, when the noise reduction unit 112 is provided in the enlarged still image generation unit 64, the image signal selection unit 114 is further provided. However, when the super-resolution processing unit 113 is provided in the enlarged still image generation unit 64, An image signal selection unit 114 similar to that in FIG. In this case, it is possible to generate a still image signal with particularly good image quality by performing super-resolution processing using a plurality of still image signals selected by the image signal selection unit 114 with less blur.

  As in the above modification, a plurality of still image pickup frames F1 and F2 are inserted between the moving image pickup frames M1 to M11 in response to one still image acquisition instruction, and each When the enlarged still images are generated using the still image signals acquired in the still image pickup frames F1 and F2, and the enlarged still image 92 displayed on the monitor 18 is updated, the enlarged still image generating unit 64 It is preferable to automatically track a lesion or the like in a portion that is enlarged by electronic zoom. In this case, as illustrated in FIG. 14, the enlarged still image generation unit 64 includes, for example, a feature point detection unit 121 and an enlarged region setting unit 122. As illustrated in FIG. 15, the feature point detection unit 121 detects a plurality of feature points 124 to be observed using a still image signal 123. The feature point 124 is a point that represents a feature of an observation target, such as a point where a change in pixel value (including changes in brightness or color) is a maximum or minimum, a start point or end point of a curve, or a point where the curvature of a curve is a maximum or minimum ( Pixel). The enlargement area setting unit 122 specifies the lesion etc. 125 from the distribution of the feature points 124 detected by the feature point detection unit 121, and sets the area where the specified lesion etc. 125 is located at the center as the area 126 to be enlarged by electronic zoom. To do.

  As described above, when the feature point to be observed is detected by the feature point detection unit 121 and the region 126 to be enlarged by the electronic zoom is set by the feature point 124 detected by the feature point detection unit 121, the enlarged still image displayed on the monitor 18 is displayed. Even when the image 92 is updated, the lesion etc. 125 can be automatically tracked. For this reason, as long as the lesion etc. 125 is in the field of view (in the non-magnified video 91) while observing the observation target from a distant view, the enlarged still image 92 always appropriately enlarges and displays the periphery of the lesion etc. 125. can do.

  In the above modification, the lesion etc. 125 is specified by the feature point 124. However, when the lesion etc. 125 is designated using the console 20 etc. from the enlarged still image 92 displayed on the monitor 18, the designated lesion etc. 125 is displayed. May be tracked. In the modification, the feature point 124 is detected from the still image signal and the region 126 to be enlarged by electronic zoom is set. However, the feature point 124 is detected and the region 126 to be enlarged by electronic zoom is set. Alternatively, a moving image signal may be used.

  How many still image pickup frames are inserted between the moving image pickup frames M1 to M11 or the like when a plurality of still image pickup frames F1 and F2 are inserted in response to one still image acquisition instruction It is preferable that whether to update an enlarged still image, to perform noise reduction processing, to perform super-resolution processing, or the like can be changed by setting. It is preferable that the enlargement ratio of the enlarged still image 92 can be changed by setting.

  In the above-described embodiment and the modification, the present invention is implemented by the endoscope system that performs observation by inserting the endoscope 12 provided with the imaging sensor 48 into the subject. The present invention is preferred. For example, as shown in FIG. 16, the capsule endoscope system includes at least a capsule endoscope 400 and a processor device (not shown).

  The capsule endoscope 400 includes a light source 402, a control unit 403, an image sensor 404, an image processing unit 406, and a transmission / reception antenna 408. A light source 402 corresponds to the light source 36 of the above-described embodiment and modification.

  The control unit 403 functions in the same manner as the light source control unit 37 and the control unit 71 of the above-described embodiment and modification. Further, the control unit 403 can communicate wirelessly with the processor device of the capsule endoscope system by the transmission / reception antenna 408. The processor device of the capsule endoscope system is substantially the same as the processor device 16 of the above-described embodiment and the modified example, but the image processing unit 406 corresponding to the image processing unit 62 is provided in the capsule endoscope 400 and generated. The endoscopic image is transmitted to the processor device via the transmission / reception antenna 408. The image sensor 404 is configured in the same manner as the image sensor 48 of each of the above embodiments.

DESCRIPTION OF SYMBOLS 10 Endoscope system 22b Freeze button 36 Light source 63 Movie generation part 64 Enlarged still picture generation part 71 Control part 400 Capsule endoscope

Claims (12)

A light source that emits illumination light;
An imaging sensor for imaging an observation target irradiated with illumination light;
A still image acquisition instruction unit for inputting a still image acquisition instruction for instructing acquisition of the still image to be observed;
When the still image acquisition instruction is input, a still image that generates a still image obtained by enlarging the observation target by electronic zoom between the moving image pickup frames for acquiring the moving image signal that forms the observation target moving image. A control unit that inserts a still image capturing frame for acquiring an image signal;
A moving image generation unit that generates the observation target moving image using the moving image signal;
An enlarged still image generating unit that generates an enlarged still image that is a still image obtained by enlarging the observation target by electronic zoom using the image signal for still image;
An endoscope system comprising:   The endoscope system according to claim 1, wherein the control unit makes a shutter speed of the still image pickup frame faster than a shutter speed of the moving image pickup frame.   The endoscope system according to claim 2, wherein the control unit makes the light amount of the illumination light of the enlarged still image capturing frame larger than the light amount of the illumination light of the moving image capturing frame.   The said control part inserts the said some imaging frame for still images between the said imaging frames for moving images with respect to the input of the said one still image acquisition instruction | indication. The endoscope system described.   The enlarged still image generation unit generates a plurality of enlarged still images using a plurality of still image signals acquired by the plurality of still image capturing frames, and generates a single still image acquisition instruction. The endoscope system according to claim 4, wherein the display of the enlarged still image is updated a plurality of times in response to the input.   The enlarged still image generation unit includes a noise reduction unit that performs noise reduction processing using the plurality of still image signals acquired by the plurality of still image pickup frames, and the still image subjected to the noise reduction processing The endoscope system according to claim 4, wherein the enlarged still image is generated using an image signal for operation.   The enlarged still image generation unit includes a super-resolution processing unit that performs super-resolution processing using the plurality of still image signals acquired with the plurality of still image capturing frames, and performs the super-resolution processing. The endoscope system according to claim 4, wherein the enlarged still image is generated using the still image signal.   The enlarged still image generation unit includes an image signal selection unit that compares a plurality of still image signals and selects a plurality of still image signals with less blur from the plurality of still image signals. The endoscope system according to claim 6 or 7 provided.   The enlarged still image generating unit includes an enlarged region setting unit that sets a region to be enlarged by the electronic zoom using the moving image signal or the still image signal, and the region set by the enlarged region setting unit The endoscope system according to claim 4, wherein the magnified still image obtained by enlarging the image is generated.   The enlarged still image generation unit includes a feature point detection unit that detects a feature point of the observation target using the moving image image signal or the still image signal, and the enlarged region setting unit includes the feature inspection. The endoscope system according to claim 9, wherein an area to be enlarged by the electronic zoom is set using the feature points detected by a projecting portion.   The feature point detection unit detects a plurality of the feature points, and the enlargement region setting unit enlarges a region where the feature point selected from the plurality of feature points is located at the center by the electronic zoom. The endoscope system according to claim 10, wherein the endoscope system is set in a region. A light source that emits illumination light, an imaging sensor that images an observation target irradiated with the illumination light, and a still image acquisition instruction unit that inputs a still image acquisition instruction that instructs acquisition of a still image of the observation target. In the operation method of the endoscope system,
A still image obtained by enlarging the observation target by electronic zoom during a moving image capturing frame for acquiring a moving image signal forming the observation target moving image when the control unit receives the still image acquisition instruction. Inserting a still image pickup frame for acquiring a still image signal for generating
A moving image generating unit generating the moving image to be observed using the moving image signal;
An enlarged still image generating unit generating an enlarged still image that is a still image obtained by enlarging the observation target by electronic zoom using the still image signal;
A method of operating an endoscope system comprising:

Images