JP5985916B2 - Endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus that images a subject such as an inner wall of an organ, and more particularly to a white balance adjustment process performed using a white balance adjustment tool.

  In an electronic endoscope apparatus, a cylindrical white balance adjustment tool is used when performing white balance adjustment processing. The video scope tip is inserted into the adjustment tool, and color imaging is performed on the white cylinder bottom. The gain value is set so that the ratio of R, G, and B is 1: 1: 1.

  The light irradiation range inside the white balance adjustment tool varies depending on the distance between the scope tip and the bottom of the cylinder. When the bottom surface and the scope tip are too close, only a part of the bottom surface of the cylinder is irradiated, and when it is far apart, the irradiation range includes both the bottom surface and the side surface of the cylinder. The light intensity of the reflected light also changes according to the distance interval, which affects the white balance value.

  In order to maintain an appropriate distance between the scope tip and the bottom of the cylinder, a scope tip positioning mechanism is provided inside the white balance adjuster, for example (see Patent Document 1). In this case, an elastic holding cylinder is provided inside the cylinder, and the scope tip is positioned in contact with the holding cylinder.

JP 2006-334112 A

  The size of the scope tip varies depending on the type (observation target organ), and the appropriate distance interval varies depending on the scope. For this reason, it is difficult to position the scope tip at an appropriate position by using a positioning mechanism inside the adjuster for various size scopes.

  Further, the appropriate position of the scope tip also varies depending on the imaging characteristics such as the size (number of pixels) of the image sensor provided at the scope tip and the power of the objective lens.

  Therefore, regardless of the structure and size of the scope tip, it is necessary to position the scope tip at an appropriate distance from the bottom surface inside the adjustment tool.

  An endoscope apparatus according to the present invention includes an edge detection unit that detects an edge of an inner bottom surface of a white balance adjustment tool in a photographing state in which a scope tip is inserted into a bottomed cylindrical white balance adjustment tool, and a white balance adjustment tool Display means for displaying on the screen a guide frame that serves as an index when positioning the distal end of the scope inserted into the display, and the display means marks the detected inner bottom edge on the screen together with the guide frame.

  Since the edge of the inner bottom surface is identified and displayed so that it can be compared with the guide frame, that is, the feature is extracted and drawn, it can be determined from the screen display whether or not it matches the guide frame. When they match, it can be considered that the scope tip is held at an appropriate position, that is, the inner bottom surface and the scope tip are at an appropriate distance in the axial direction of the adjuster.

  The operator can determine from the screen display that the white balance can be adjusted, or the endoscope apparatus can automatically determine that the white balance can be adjusted. For example, it is possible to further include white balance adjustment permission means for determining whether or not to permit the white balance adjustment processing by comparing the guide frame with the marked inner bottom surface edge.

  The white balance adjustment permission means can permit the white balance adjustment process to be executed based on the degree of coincidence between the guide frame and the marked inner bottom surface edge. For example, a guide frame having a width in the radial direction is displayed, and the white balance adjustment permission unit permits execution of the white balance adjustment process when the inner bottom edge marked in the guide frame region fits.

  In order to make it easy to compare the extracted edge image and the guide frame on the screen, the display means can erase the marked inner bottom edge and the edge portion other than the guide frame from the screen. The white balance adjustment permission unit may delete the marked inner bottom edge and the guide frame from the screen when the white balance adjustment process is completed.

  Thus, according to the present invention, appropriate white balance adjustment can be performed for various types of scopes.

It is a block diagram of the electronic endoscope apparatus which is this embodiment. It is the side view which showed the white balance adjustment tool. It is the top view seen from the white balance adjustment tool. It is the figure which showed the image | video when the inside of a white balance adjustment tool was imaged. It is the figure which showed the screen display when a scope front-end | tip part exists in an appropriate position. It is the figure which showed the flowchart of the white balance adjustment process performed by a system control circuit. It is the figure which showed the subroutine of step S102 of FIG.

  Hereinafter, the electronic endoscope apparatus according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a block diagram of an electronic endoscope apparatus according to this embodiment.

  The electronic endoscope apparatus includes a video scope 10 whose insertion portion is inserted into the body, and a processor 30, and the video scope 10 is detachably connected to the processor 30. A monitor 60 is connected to the processor 30.

  The processor 30 includes a lamp 32 that emits white light, and the light emitted from the lamp 32 is incident on the light guide 12 provided in the video scope 10 via the condensing optical system 34. The light incident on the light guide 12 exits from the scope distal end 10T via a diaphragm (not shown) and the light distribution lens 14, and is irradiated onto the subject (observation site).

  The light reflected from the subject is imaged by the objective lens 16, and a subject image is formed on the light receiving surface of the CCD 18. On the light receiving surface of the CCD 18, a color filter (not shown) is arranged in which color filter elements made of Cy, Ye, G, Mg, or R, G, B are arranged in a mosaic pattern.

  During endoscopic observation, pixel signals for one field are sequentially read out from the CCD 18 at predetermined time intervals (1/60 seconds for the NTSC system and 1/50 seconds for the PAL system). The read pixel signals for one field are sequentially sent to the image signal processing circuit 36 of the processor 30.

  The image signal processing circuit 36 performs gamma processing, white balance processing, color conversion processing, noise reduction, and the like on the pixel signals for one field. Thereby, R, G, and B image signals are sequentially generated. The generated R, G, B image signals are temporarily stored in the memory 38 and then sent to the monitor 60 via the video signal processing circuit 42.

  The system control circuit 40 outputs control signals to the image signal processing circuit 36, a timing generator (not shown), etc., and controls the operation of the entire processor. When the white balance adjustment button 37 provided on the front panel of the processor 30 is operated, white balance adjustment processing using the white balance adjustment tool 50 can be executed.

  FIG. 2 is a side view showing the white balance adjusting tool 50. FIG. 3 is a plan view of the white balance adjusting tool 50 as viewed from above.

  The white balance adjusting tool 50 is a bottomed cylindrical body provided with a cylindrical recess 50O into which the scope distal end portion 10T can be inserted, and the inner bottom surface 50B and the inner side surface 50C are painted white. The operator holds the scope distal end portion 10T in the white balance adjustment tool 50 during the white balance adjustment process.

  In the white balance adjustment process, shooting is performed using the inner bottom surface 50B of the white balance adjustment tool 50 as a subject. The R, G, and B gain values are set so that the R, G, and B image signal components are 1: 1: 1 while the inner bottom surface 50B is projected.

  After setting the R, G, and B gain values (white balance adjustment processing), the operator starts endoscopic observation. During the endoscopic operation, the image signal processing circuit 36 executes white balance processing (gain processing) based on the set gain value.

  During the white balance adjustment process, the operator must hold the scope tip 10T in an appropriate position. The appropriate distance H between the scope tip 10T and the inner bottom surface 50B is maintained by the image displayed on the monitor 60. Below, the screen display which assists holding position adjustment of the scope front-end | tip part 10T is demonstrated.

  FIG. 4 is a view showing an image when the inside of the white balance adjustment tool is imaged. FIG. 5 is a diagram showing a screen display when the scope distal end portion 10T is at an appropriate position. The screen display contents during white balance adjustment will be described with reference to FIGS.

  FIG. 4A shows an image displayed on the screen 60 </ b> S of the monitor 60 when shooting without operating the white balance adjustment button 37. Since the inner bottom surface 50B and the inner side surface 50C of the white balance adjusting tool 50 are white, the entire screen 60S of the monitor 60 becomes a white image.

  On the other hand, since the edge 50D of the inner bottom surface 50B becomes a boundary line with the inner side surface 50C, the edge image 50E is displayed in a circle line shape. However, since the whole is a white image, visual recognition is difficult. The size of the mask M on the screen follows the mask size of the CCD 18. The area outside the mask M is a black image.

  The light emitted from the scope tip 10T is not completely parallel light but diffused light, and the intensity of the reflected light varies depending on the distance between the scope tip 10T and the inner bottom surface 50B. Accordingly, if the scope distal end portion 10T is held at an appropriate position along the axial direction of the white balance adjusting tool 50, and the R, G, and B gain values are not set there, an observation image in which inappropriate white balance adjustment is performed. Will be displayed.

  Therefore, it is necessary to determine the position of the scope tip portion 10T that can irradiate the inner side surface 50C of the white balance adjustment tool 50 as much as possible and irradiate the entire inner bottom surface 50B as an appropriate scope holding position.

  When reflected light from the entire inner bottom surface 50B is imaged by the CCD 18, the position where the edge 50D of the inner bottom surface 50B is projected on the screen so as to reach both ends of the mask M serving as an imaging region is an appropriate scope holding position. ing. Therefore, a frame (hereinafter referred to as a guide frame) GF serving as an index (guide) for the operator to adjust the position of the scope distal end portion 10T at this appropriate position is displayed on the screen.

  The guide frame GF is formed in a circular shape in accordance with the circle shape of the edge 50D of the inner bottom surface 50B. The guide frame GF has a radial width J. The radial width J can be custom adjusted as appropriate.

  On the other hand, since the edge image 50E of the inner bottom surface 50B is difficult to visually recognize as described above, the edge image itself extracted by edge detection is marked as a circle instead of displaying the edge image itself. That is, the marking display and the identification display are performed so as to be compared with the guide frame GF.

  FIG. 4C shows an edge image (hereinafter referred to as an extracted edge image) SC drawn based on edge detection. The extracted edge image SC is displayed as a circle line having substantially no radial width. As a method for detecting an edge from the edge image 50E, Hough transform is applied here.

  Furthermore, in order to make it easy to compare the guide frame GF and the extracted edge image SC on the screen, the boundary portion of the mask M is erased from the screen. Here, the mask M is removed by the chromatic color detection method. Specifically, the guide frame GF and the extracted edge image SC are drawn in specific colors, respectively, and portions other than the chromatic color edge portions are removed. Thereby, the mask boundary part and the outside of the mask area are erased from the screen.

  Therefore, when the white balance adjustment button 37 is pressed, only the extracted edge image SC and the guide frame GF are displayed on the screen as shown in FIG. When the position of the scope tip portion 10T moves along the axial direction of the white balance adjuster 50, the display position and size of the extraction edge image SC also change. The operator adjusts the position of the scope distal end portion 10T so that the extracted edge image SC and the guide frame GF coincide with each other.

  FIG. 5 shows a screen in which the extracted edge image SC is contained in the guide frame GF having the radial width J. When the extracted edge image SC fits in the guide frame GF, it can be considered that the scope distal end portion 10T is in an appropriate position.

  On the other hand, the extracted edge image SC drawn by edge detection is not necessarily a perfect circle due to the influence of noise or the like. Therefore, the degree of coincidence between the extracted edge image SC and the guide frame GF is measured, and when the display position of the extracted edge image SC can be regarded as corresponding to the display position of the guide frame GF, the scope tip 10T is held at the appropriate position. to decide.

  FIG. 6 is a flowchart of white balance adjustment processing executed by the system control circuit 40. FIG. 7 is a diagram showing a subroutine of step S102 of FIG. When the scope tip portion 10T is inserted into the white balance adjustment tool 50 and the white balance adjustment button 37 is operated, the processing is started.

  After the captured image stored in the memory 38 is acquired (S101), the white balance check process shown in FIG. 7 is performed. First, the guide frame GF is displayed, the edge 50D of the inner bottom surface 50B is detected by edge detection, and the extracted edge image SC is displayed (S201, S202). Then, other image portions are removed from the screen by chromatic color detection, and only the guide frame GF and the extracted edge image SC are displayed on the screen (S203).

  Then, in order to collate the guide frame GF with the extracted edge image SC, the matching rate X (%) representing the degree of matching is calculated (S204), and it is determined whether or not the matching rate exceeds the threshold value X0 (%). (S205). Here, the matching rate X is obtained by the ratio of the extracted edge image SC, which is a circle line, within the area of the guide frame GF in the entire circle.

  When the matching rate X exceeds the threshold value X0, it is determined that white balance adjustment is possible, and when the matching rate X is equal to or less than the threshold value X0, it is determined that white balance is prohibited (S206, S207).

  In step S103 of FIG. 6, it is determined whether or not the white balance permission is determined by the subroutine of FIG. When the white balance permission is determined, the extracted edge image SC and the guide frame GF are erased (S104), and white balance adjustment processing is executed (S105). Accordingly, the gain value is set so that R, G, and B are 1: 1: 1.

  On the other hand, when the white balance adjustment is not permitted, the process returns to step S101, and steps S101 to S103 are repeated. The operator adjusts the position of the scope distal end portion 10T so that the extracted edge image SC is within the guide frame GF region.

  As described above, according to the present embodiment, in the white balance adjustment process using the white balance adjuster 50, the guide frame GF is displayed and the edge 50D of the inner bottom surface 50B of the white balance adjuster 50 is extracted by edge detection. The extracted edge image SC of the circle line is displayed. Then, when the extracted extracted edge image SC fits in the guide frame GF, execution of white balance adjustment processing is permitted.

  Since the position of the scope tip is adjusted by the screen display, the scope tip can be positioned at an accurate position without using a special structure inside the white balance adjuster. In particular, since the guide frame is determined according to the mask (imaging area), it is possible to hold the scope tip at an appropriate position regardless of the size of the scope tip, imaging characteristics, and the like.

  The guide frame may not use the entire mask area. Further, the position of the guide frame may be stored in the memory in accordance with the type of scope. The degree of coincidence between the guide frame and the extracted edge image can also be determined based on other than the matching rate.

  Instead of automatically adjusting the white balance, the operator may allow the white balance adjustment by himself / herself from the screen display and input an operation button or the like to execute the white balance adjustment process.

  In addition, in order to detect the edge of an internal bottom face clearly, you may mark an edge with specific colors, such as red. Alternatively, a plurality of LEDs that emit light having a wavelength of a specific color along the edge may be arranged and lit while the scope tip is displayed.

10 Videoscope 18 CCD
30 processor 36 image signal processing circuit 40 system control circuit 50 white balance adjustment tool 50B inner bottom surface 50D edge SC extraction edge image GF guide frame

Claims (7)

Edge detection means for detecting an edge of the inner bottom surface of the white balance adjustment tool in a photographing state in which the scope tip is inserted into a bottomed cylindrical white balance adjustment tool;
Display means for displaying on the screen a guide frame serving as an index when positioning the distal end of the scope inserted into the white balance adjustment tool;
The endoscope apparatus, wherein the display means marks the detected inner bottom edge on a screen together with a guide frame.   The endoscope according to claim 1, further comprising a white balance adjustment permission unit that determines whether or not the white balance adjustment process is permitted by comparing the guide frame with the marked inner bottom surface edge. apparatus.   The endoscope apparatus according to claim 2, wherein the white balance adjustment permission unit permits execution of white balance adjustment processing based on a degree of coincidence between the guide frame and the marked inner bottom surface edge. The display means displays a guide frame having a radial width;
The endoscope according to any one of claims 2 to 3, wherein the white balance adjustment permission unit permits the white balance adjustment process to be executed when the inner bottom edge marked within the guide frame region is within the guide frame region. apparatus.   The endoscope apparatus according to any one of claims 1 to 4, wherein the display means erases the marked inner bottom edge and edge portions other than the guide frame from the screen. The white balance adjustment permitting section, the white balance adjustment process is completed, the endoscope apparatus according to any one of claims 2 to 4, characterized in that erasing the internal bottom edge and guide frame, labeled from the screen .   The endoscope apparatus according to claim 1, wherein the display unit displays a guide frame having a size corresponding to a mask size of an image sensor provided at a distal end portion of the scope.

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