JP2006020276A - Endoscope for measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope for measurement which images a measuring object, reads the image as an original image and performs measurement on the basis of the position of a measuring point on the read original image, and, specially performs high-accuracy measurement by easily designating the measuring point. <P>SOLUTION: In an endoscope apparatus for measurement, for example, magnified image generation processing is performed on an original image resulting from imaging the measuring object. When designating a measuring point, the pixel interval of the original image is designated for large movement, the pixel interval of the original image is designated in more details for detailed movement, and the measuring point is efficiently designated. Furthermore, above setting is switched to more easily designate the measuring point. When the measuring point is separated, for example, a designated point is made closer to the measuring point with a moving amount as a pixel interval, the unit of the moving amount is then switched to detailed setting more than the pixel interval, and the designated point is accurately made close to the measuring point, so that a user easily designates the measuring point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a measurement endoscope apparatus that captures an image of a measurement object, reads it as an original image, and performs measurement based on the position of a measurement point on the read original image.

  Today, a measuring endoscope apparatus is used for measuring scratches and chips on various machine parts. Such a measuring endoscope apparatus captures a measurement object, reads an original image, and performs measurement based on the position of the measurement point on the read original image.

  Patent Document 1 proposes a method for enlarging an original image and designating measurement points on the enlarged image as a technique for designating measurement points on the original image. This method is a configuration in which a pixel corresponding to a measurement point is selected and designated from pixels on the enlarged image, and measurement is performed based on the position of the pixel on the original image corresponding to the designated pixel. Furthermore, the position of the designated measurement point on the original image can be calculated in units of reciprocal magnification. Therefore, based on the position calculated in this way, it is possible to measure in units smaller than the pixel interval of the original image.

  Here, an example of specifying measurement points by a conventional method is shown. For example, FIG. 12 shows an original image to be measured. As shown in the figure, the original image has a white background and two black lines having a thickness of 2 pixels intersect at right angles. The measurement point is the center of the intersection of two lines, and an area including this point is an enlarged area.

FIG. 13 is an enlarged view of this enlarged region. A + mark indicating a designated point is displayed on the enlarged image shown in FIG. In the above technique, measurement points are designated on the enlarged image shown in the figure, and measurement is performed based on the positions of the pixels on the original image corresponding to the pixels on the designated enlarged image. Further, as described above, the position on the original image corresponding to the pixel on the designated enlarged image can be calculated in units of the reciprocal of the enlargement magnification, and measurement can be performed based on this position.
JP-A-4-332523

  However, in the conventional method, when the measurement points are specified in units smaller than the pixel interval of the original image, the point having the most characteristic as the measurement points is determined and specified between the pixels of the original image. However, it is difficult to determine the points with the most characteristics. In other words, the simple enlargement simply enlarges the pixels of the original image, and the feature is difficult to appear. Therefore, the user predicts and designates the position having the feature, and it is difficult to designate it accurately. On the other hand, in the enlargement by the first-order or higher-order interpolation such as linear interpolation, it is difficult to determine the position designation because the image is easily blurred.

  Further, in the conventional method, the unit for specifying the position of the measurement point is limited to the pixel interval of the original image or the inverse of the enlargement magnification, and thus the specified position of the measurement point is limited. That is, in order to make the unit for specifying the position of the measurement point finer than the pixel interval of the original image, it is necessary to enlarge the original image. As a result, in order to specify the position of the measurement point in fine units, the enlargement magnification must be increased. However, if the enlargement magnification is increased, the enlargement range becomes narrow and the enlarged image becomes difficult to understand, making it difficult to specify the measurement point. It becomes.

  An object of the present invention is to provide a measurement endoscope apparatus that can easily specify the position of a measurement point, for example, can arbitrarily specify the position regardless of the magnification, and can perform high-precision measurement.

  According to the present invention, there is provided an original image acquisition means for acquiring an image sampled and read in pixel units as an original image, and re-sampling at a predetermined position with respect to a part or all of the original image. And a re-sampling image generating means for generating an image, wherein a sampling point corresponding to each pixel in a part or all of a region of the original image is smaller than a pixel interval of the original image A sampling point moving means that moves in units, and a measurement point that specifies the position of the measurement point on the original image in units smaller than the pixel interval of the original image by moving the sampling point to a desired point by the sampling point moving means Provided is a measuring endoscope apparatus including a position specifying unit and a measuring unit that performs measurement in units smaller than the pixel interval of an original image based on the position of a specified measurement point. It can be achieved by the.

  In addition to the above configuration, a sampling point moving image generating unit that generates an image in which the sampling point is moved by the sampling point moving unit, an enlarged image generating unit that generates an enlarged image by enlarging the sampling point moving image, This can be achieved by providing an endoscope apparatus for measurement having enlarged image display means for displaying an enlarged image and measurement point position designation means for designating the position of the measurement point on the enlarged image.

  Furthermore, this can be achieved by providing a measuring endoscope apparatus provided with sampling point movement amount unit designation means for designating a unit of movement amount of the moved sampling point by the sampling point movement means.

Further, filter means is provided for performing a filtering process so as to reduce the rate of change of the enlarged image signal with respect to the enlarged image displayed on the enlarged image display means.
With the above configuration, it is easy to determine a position having a characteristic point necessary for specifying a measurement point in units smaller than the pixel interval of the original image. In addition, since the unit for specifying the position of the measurement point can be set arbitrarily, measurement with higher accuracy than before can be performed, and the ease of specifying the measurement point is improved by enlargement with an arbitrary magnification. When the measurement point is designated using the enlarged image, the noise of the enlarged image displayed on the enlarged image display means can be reduced, and the measurement point can be easily specified.

According to the present invention, when the position of a measurement point is specified in a unit smaller than the pixel interval of the original image, it becomes easy to determine a point having a necessary characteristic.
In addition, since the unit for specifying the position of the measurement point can be set arbitrarily, measurement with higher accuracy than before can be performed.

  Furthermore, the measurement point can be specified more easily by enlargement at an arbitrary magnification.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 11 relate to the present embodiment, FIG. 1 is a diagram illustrating a measurement endoscope apparatus, FIG. 2 is a block diagram illustrating a configuration of the measurement endoscope apparatus, and FIG. FIG. 4 is a perspective view showing a configuration in which a direct-viewing stereo optical adapter is attached to the distal end portion of a measurement endoscope, and FIG. 5 is a cross-sectional view taken along line AA in FIG. 6 is a diagram for explaining a method for obtaining the three-dimensional coordinates of the measurement point by stereo measurement, FIG. 7 is a flowchart for explaining the flow of measurement by the endoscope apparatus for measurement, and FIG. 8 is the measurement of FIG. FIG. 9 is a diagram showing an enlarged image of a sampling point moving image, and FIG. 10 is a diagram showing the principle of generating the sampling point moving image and its enlarged image. FIG. 11 shows the original image. That illustrates a mobile sampling points and the sampling points.

  First, as shown in FIG. 1, the measurement endoscope apparatus 10 houses an endoscope insertion portion 11 in which an optical adapter including a stereo measureable member is detachable, and the endoscope insertion portion 11. A control unit 12, a remote controller 13 that performs operations necessary to execute various operation controls for the entire system of the measuring endoscope apparatus 10, and display of endoscopic images and operation control contents (for example, processing menus). A liquid crystal monitor (hereinafter referred to as “LCD”) 14, a normal endoscopic image, or a face-mount display (hereinafter referred to as “FMD”) 17 capable of stereoscopically viewing the endoscopic image as a pseudo stereo image; And an FMD adapter 18 for supplying image data to the FMD 17.

  Next, the system configuration of the measurement endoscope apparatus 10 will be described in detail with reference to FIG. As shown in FIG. 2, the endoscope insertion portion 11 is connected to an endoscope unit 24. The endoscope unit 24 is mounted, for example, in the control unit 12 shown in FIG. The endoscope unit 24 includes a light source device for obtaining illumination light necessary for photographing and an electric bending device for electrically bending the endoscope insertion portion 11. ing. An imaging signal from the individual imaging element 43 (see FIG. 5) at the distal end of the endoscope insertion portion 11 is input to a camera control unit (hereinafter referred to as CCU) 25. The CCU 25 converts the supplied imaging signal into a video signal such as an NTSC signal and supplies it to a main processing circuit group in the control unit 12.

  As shown in FIG. 2, the main circuit group mounted in the control unit 12 includes a CPU 26, a ROM 27, a RAM 28, a PC card interface (hereinafter referred to as a PC card) that controls various functions based on the main program. Card I / F) 30, USB interface (hereinafter referred to as USB I / F) 31, RS-232C interface (hereinafter referred to as RS-232C I / F) 29, audio signal processing circuit 32, and video signal And a processing circuit 33. The CPU 26 executes a program stored in the ROM 27 and controls various circuit units so as to perform processing according to the purpose, thereby controlling the operation of the entire system.

  The RS-232c I / F 29 is connected to the CCU 25, the endoscope unit 24, and the remote controller 13, respectively. The remote controller 13 is for performing control and operation instructions of the CCU 25 and the endoscope unit 24. The RS-232C I / F 29 is for performing communication necessary for controlling the operation of the CCU 25 and the endoscope unit 24 based on an operation by the remote controller 13.

  The USB I / F 31 is an interface for electrically connecting the control unit 12 and the personal computer 21. When the control unit 12 and the personal computer 21 are connected via the USB I / F 31, various kinds of instructions such as an endoscopic image display instruction in the control unit 12 and image processing during measurement are performed on the personal computer 21 side. Support control can be performed, and control information and data necessary for various processes can be input and output between the control unit 12 and the personal computer 21.

  The PC card I / F 30 has a configuration in which a PCMCIA memory card 23 and a compact flash (registered trademark) memory card 22 are detachably connected. That is, when any one of the memory cards is inserted, the control unit 12 reproduces data such as control processing information and image information stored in the memory card as a recording medium under the control of the CPU 26, and Data such as control processing information and image information can be supplied to the memory card via the PC card I / F 30 and recorded in the control unit 12 via the PC card I / F 30.

  The video signal processing circuit 33 displays the video signal from the CCU 25 and the operation menu generated by the control of the CPU 26 so as to display a composite image obtained by combining the endoscopic image supplied from the CCU 25 and the graphic operation menu. The display signal based on the image is synthesized, and further, necessary processing for displaying on the screen of the LCD 14 is performed and supplied to the LCD 14. As a result, a composite image of the endoscope image and the operation menu is displayed on the LCD 14. In the video signal processing circuit 33, it is also possible to simply perform processing for displaying an endoscopic image or an image such as an operation menu alone.

  Further, the control unit 12 shown in FIG. 1 is provided with an external video input terminal 70 for inputting video to the video signal processing circuit 33 without going through the CCU 25. When a video signal is input to the external video input terminal 70, the video signal processing circuit 33 outputs the composite image in preference to the endoscopic image from the CCU 25.

  The audio signal processing circuit 32 is generated by being collected by the microphone 20 and recorded on a recording medium such as a memory card, or an audio signal obtained by reproducing a recording medium such as a memory card, or generated by the CPU 26. The audio signal is supplied. The audio signal processing circuit 32 performs processing (amplification processing or the like) necessary for reproducing the supplied audio signal and outputs the processed signal to the speaker 19. Thereby, an audio signal is reproduced by the speaker 19.

  As shown in FIG. 3, the remote controller 13 includes a joystick 61, a lever switch 62, a freeze switch 63, a store switch 64, a measurement execution switch 65, an enlarged display switching WIDE switch 66, and a TELE switch 67. ing.

  In the remote controller 13, the joystick 61 is a switch for performing a bending operation of the distal end portion of the endoscope. The bending operation can be finely adjusted by giving an operation instruction freely in any direction of 360 degrees or by pressing down directly below. It is possible to give instructions. The lever switch 62 is a switch for performing selection operation of a selection item by moving a pointer and pressing down directly when performing various menu operations displayed in graphics and measurement, and has substantially the same shape as the joystick switch 61. It is composed of. The freeze switch 63 is a switch related to the LCD 14 display. The store switch 64 is a switch used when recording a still image on the PCMCIA memory card 23 (see FIG. 2) when a still image is displayed by pressing the freeze switch 63. The measurement execution switch 65 is a switch used when executing measurement software. The enlarged display switching WIDE switch 66 and the TELE switch 67 are used for enlarging and reducing the endoscopic image. The freeze switch 63, the store switch 64, and the measurement execution switch 65 are configured to employ, for example, an on / off pressing type.

  The endoscope image captured by the endoscope insertion unit 11 is enlarged or reduced by the video signal processing circuit 33 as necessary, and is output to the LCD 14. In this case, the magnification or reduction magnification is controlled by the WIDE switch 66 and the TELE switch 67. Further, the WIDE switch 66 and the TELE switch 67 also control the magnification when displaying an enlarged image during measurement execution.

  The WIDE switch 66 and the TELE switch 67 are used to control the enlargement and reduction of the endoscope image captured by the endoscope insertion unit 11 and the magnification when displaying the enlarged image at the time of measurement execution. This is done with a configuration consisting of switches. However, there are cases where it is difficult or impossible to provide such two switches in the operation instruction means such as a remote controller. In such a case, the enlargement / reduction control can be performed by one switch. That is, each time this switch is pressed, the magnification is increased or decreased to a predetermined magnification A. After the predetermined magnification A is set, the magnification is decreased or increased to a predetermined magnification B every time the switch is pressed. By repeating this control, enlargement / reduction control can be performed by one switch.

Next, the configuration of a stereo optical adapter which is a kind of optical adapter used in the measurement endoscope apparatus 10 of the present embodiment will be described with reference to FIGS.
4 and 5 show a state in which the stereo optical adapter 37 is attached to the endoscope distal end portion 39. The stereo optical adapter 37 is connected to the male screw 54 of the endoscope distal end portion 39 by the female screw 53 of the fixing ring 38. It is fixed by screwing.

  In addition, a pair of illumination lenses 36 and two objective lens systems 34 and 35 are provided at the tip of the stereo optical adapter 37. The two objective lens systems 34 and 35 form two images on the image sensor 43 provided in the endoscope distal end 39. The image pickup signal obtained by the image pickup device 43 is supplied to the CCU 25 via the electrically connected signal line 43a and the endoscope unit 24 shown in FIG. 2, and converted into a video signal by the CCU 25. It is supplied to the video signal processing circuit 33 later. The video signal includes a luminance value or a luminance value and a color difference value. An image generated by the imaging signal supplied to the CCU 25 is called an original image.

Next, how to obtain the three-dimensional coordinates of the measurement point by stereo measurement will be described with reference to FIG. The coordinates of the measurement points on the original image captured by the left and right optical systems are (XL, YL) and (XR, YR), respectively, and the three-dimensional coordinates of the measurement points are (X, Y, Z). . However, the origins of (XL, YL) and (XR, YR) are the intersections of the optical axis in the left and right optical systems and the image sensor 43, respectively, and the origins of (X, Y, Z) are the left and right sides. Is the midpoint of the optical center. If the distance between the left and right optical centers is D and the focal length is F, the triangulation method
X = t × XR + D / 2
Y = t × YR
Z = t × F
However, t = D / (XL-XR).

  In this way, when the coordinates of the measurement point on the original image are determined, the three-dimensional coordinates of the measurement point are obtained using the known parameters D and F. By obtaining three-dimensional coordinates of several points, various measurements such as the distance between two points, the distance between two points and the distance between one point, area, depth, and surface shape are possible.

  In the measuring endoscope apparatus having the above configuration, the processing operation of this example will be described below with reference to FIGS. Here, FIG. 7 shows a flowchart of stereo measurement, and FIG. 8 shows a screen of stereo measurement. Further, the image of FIG. 8 shows an example in which a chip is generated in a turbine blade, which is an engine part of an aircraft, for example, and shows a measurement screen when measuring the outermost width of the chip.

  First, when the measurement execution switch 65 provided on the joystick 61 described above is pressed, an image sampled and read in units of pixels is acquired as an original image in step S001 of the measurement flow shown in FIG. Is displayed on the display device. FIG. 8A shows a measurement screen including two read left and right original images, an icon for instructing a measurement operation, and a pointer whose position is specified by the lever switch 62.

  Next, a measurement point is designated on the left image in step S003. This measurement point designation is executed according to the measurement point designation flow shown in FIG. First, in step S101, an enlargement area to be enlarged is set on the original image. This enlargement area setting is executed according to the enlargement area setting flow shown in FIG. That is, when the lever switch 62 is operated in step S501, the position near the measurement point on the original image is designated, and when an enlarged image display instruction is given in step S502, the enlarged region is determined in step S503. In this example, the enlarged area is an area in a predetermined range centered on the position designated by the lever switch 62.

  Next, in step S102, an enlarged image is generated. The generation of the enlarged image is executed according to the flow shown in FIG. First, in step S601, an image is generated based on the position of the sampling point in the enlarged region. The position of the sampling point in the enlarged area is the sampling position at the time of original image acquisition, and is moved in step S107 described later.

  Here, when moved, the position of the sampling point in the enlarged region deviates from the position of sampling at the time of acquisition of the original image, so an image is generated by interpolation from the pixels on the original image. As the interpolation method, nearest neighbor interpolation, linear interpolation, bicubic interpolation, or the like is used. The image generated in step S601 is set as a sampling point moving image.

  Next, in step S602, an enlargement magnification is set from the number of times the WIDE switch 66 or TELE switch 67 is pressed, and in step S603, the number of pixels of the sampling point moving image is increased by interpolation by the enlargement magnification to generate an enlarged image. To do. As the interpolation method, nearest neighbor interpolation, linear interpolation, bicubic interpolation, or the like is used. In step S604, filter processing described later is performed on the enlarged image.

  Next, in step S103, the size and position of the enlarged image are determined and displayed. Note that the display position can be superimposed on the original image. In this case, the display position of the enlarged image is always at a predetermined distance or more away from the enlarged area of the original image, so that the enlarged area and its vicinity are Prevent it from disappearing.

  Next, in step S104, a pixel to be a designated point on the enlarged image is selected. Then, a cursor indicating the designated point is displayed on the selected pixel. Note that the pixel serving as the designated point may be a predetermined fixed position on the enlarged image.

  FIG. 8B shows a measurement screen when an enlarged image is displayed by pointing near the measurement point. On the measurement screen, an enlarged image and a cursor indicating the designated point are displayed at the center of the screen. Graphs indicating the luminance of the pixels in the vertical direction and the horizontal direction from the designated point are displayed on the right and bottom of the enlarged image, respectively, and the designated point and the surrounding luminance can be confirmed. In addition, “3x” indicating that the enlargement magnification is 3 times is displayed.

  Next, in step S105, it is determined whether a measurement point is designated by the designated point. If the measurement point is not specified, the process proceeds to step S106. If the measurement point is specified, the lever switch 62 is pressed and the process proceeds to step S108.

  In step S106, it is determined whether to move the sampling point. If there is a measurement point on the enlarged image and it is not necessary to move the sampling point because the sampling point coincides with the measurement point, the process moves to step S104, and the displayed measurement point is selected as the designated point. If there is a measurement point on the enlarged image but the sampling point does not match the measurement point and the sampling point needs to be moved, or if no measurement point exists on the enlarged image, the process proceeds to step S107. In step S107, the sampling point is moved so that the measurement point is designated by the designated point on the enlarged image. The sampling point is moved according to the flow shown in FIG. First, in step S801, in order to quickly move the designated point to the vicinity of the measurement point, the unit of the movement amount of the sampling point is set to the unit of the pixel interval of the original image.

  Next, in step S802, the specified point is brought close to the measurement point by the lever switch 62. For this reason, in order to specify the measurement point with high accuracy by depressing the joystick 61, the unit of the moving amount of the sampling point is switched to a unit finer than the pixel interval. Then, the position of the sampling point is moved by the lever switch 62, and the designated point is moved to the measurement point. When the unit of the moving amount of the sampling point is set more finely than the pixel interval, an “F” icon is displayed (see FIG. 8C described later).

  By processing in this way, if the specified point is far from the measurement point, the specified point is quickly brought closer to the measurement point with the movement amount as the pixel interval, and then the unit of the movement amount is set more finely than the pixel interval, and the specified point is Close to the measurement point accurately. Therefore, the user can easily set measurement points by this processing of this example.

  The sampling point may be moved according to the following procedure. First, in step S801, the setting of the unit of movement of the sampling point is determined by the pressed state of the joystick 61 or the freeze stick 63. Next, according to the setting in step S801, the designated point is moved closer to the measurement point by the lever switch 62 in step S802.

  Next, when the position of the sampling point is moved by the process of step S107, the enlarged region is moved accordingly. After moving the sampling point, the process returns to step S102, and an enlarged image is generated and displayed again. FIG. 8C shows a measurement screen including an enlarged image when the sampling point is moved. FIG. 4D shows a measurement screen when the enlargement magnification is changed to 6 times. Further, FIG. 9E shows a measurement screen when the unit of the moving amount of the sampling point is set to the pixel interval of the original image and the sampling point is moved from the state of FIG.

In this way, by switching the unit of the movement amount of the sampling point, rough movement and fine movement can be performed, and the measurement point can be easily specified.
Next, after the designated point has moved to the measurement point by the above processing, the designated point is determined by pressing the lever switch 62 in step S105, and the position of the measurement point on the original image is determined from the position of the designated point in step S108. calculate.

  Next, in step S004, the enlarged image at the time point designated in step S003 is displayed superimposed on the left image. In step S005, a corresponding point on the right image corresponding to the measurement point designated in step S003 is searched. This search is performed in a unit smaller than the pixel interval of the original image by the template matching method of the existing image.

  Next, in step S006, the vicinity of the corresponding point on the searched right image is enlarged in the same manner as the enlargement of the left image, and is superimposed and displayed on the right image. FIG. 8F shows the measurement screen at this time. By displaying the enlarged image on the original image, it is possible to check the previous measurement point correctly and to check the matching result of the corresponding point in the right image while specifying the next measurement point. It becomes possible to prevent.

  Next, in step S007, it is determined whether to correct the position of the measurement point on the left screen. Here, when correcting the position of the measurement point on the left screen, the lever switch 62 is operated to select the icon “←” on the measurement screen, the process returns to step S003, and the measurement point is designated again. On the other hand, when not correcting, it progresses to step S008.

  In step S008, it is determined whether to correct the position of the corresponding point on the right screen. In the case of correction, the lever switch 62 is operated to select the icon [→] on the measurement screen, the process proceeds to step S010, and the measurement point on the left image is designated on the right image in the same manner as described above. Specify the corresponding points. In step S011, the periphery of the corresponding point on the right image is displayed in the same manner as the processing in step S006 described above.

  In the determination at step S007 and step S008, enlarged images around the measurement point of the left image and the corresponding point of the right image are displayed large on the left screen and the right screen, respectively, and the measurement point and the corresponding point are correctly specified. You may make it confirm whether it is.

  If the position is not corrected in step S008, the process proceeds to step S012, and it is determined whether to specify another measurement point. If it is designated, the process returns to step S003, and if not designated, the process proceeds to S013. In this process, measurement is performed based on the position of the measurement point specified above. FIG. 8G shows a measurement screen including a measurement result when a distance between two points is measured.

  In the example of the measurement result shown in FIG. 8G, the measurement unit is mm, but the measurement unit can be switched by switching the selection of “mm” and “inch” in the screen. When the measurement unit is switched, the display of the measurement result is also changed to the set unit. As a result, the measurement unit can be switched at an arbitrary timing while continuing the measurement work. This is useful when the unit you normally use differs from the unit written in the inspection manual, or when the settings are incorrect. It is also possible to change the measurement unit by setting with the menu.

  Next, details of the measurement point designation will be described using the original image shown in FIG. 12 as an example. The enlarged area shown in FIG. 12 is first enlarged as shown in FIG. However, nearest neighbor interpolation is used to increase the number of pixels for enlargement. The unit of the moving amount of the sampling point is set to 0.1 pixel so that the designated point moves to the center of the intersection of the two lines, and the sampling point is moved 0.5 pixel to the left and 0.5 pixel downward. By this processing, a sampling point moving image is generated by linear interpolation, and an enlarged image of this image is generated. FIG. 9 is an enlarged image at this time.

  Next, the principle of generating a sampling point moving image and an enlarged image thereof will be described with reference to FIG. As shown in FIG. 10A, the original image is an original image of 6 horizontal pixels × 1 vertical pixel, with the central two pixels being white and the other surrounding pixels being black. FIG. 4B shows the luminance at the sampling point of the original image.

  When this sampling point is moved to the right by 1/3 pixel of the original image, the luminance of the moved sampling point is calculated by interpolation from the pixel of the original image, and the luminance of the sampling point moving image is as shown in FIG. . If the number of pixels is increased for enlargement of the moving image of the sampling point, the luminance is as shown in FIG. From this luminance, an enlarged image shown in FIG.

  Next, the principle of generating the enlarged image shown in FIG. 9 will be described. FIG. 11 is a diagram showing sampling points and moved sampling points in the original image. In the original image shown in FIG. 13 described above, the black line extends over two sampling points. For example, on the enlarged image, a line having a thickness of 2 on the original image is simply enlarged. On the other hand, when the sampling position is moved, black is obtained when sampling is performed across two pixels in the black line, and gray is obtained by interpolation at the boundary position between white and black. Therefore, in this enlarged image, the position of the designated point is black, but the surrounding area is gray.

  As described above, in the enlarged image of the sampling point moving image, the color of the position of the designated point is clear, but a color separated from the designated point by one pixel in the original image is displayed around it. Therefore, it is possible to distinguish the color of the designated point and the other points, and it is easy to determine the position of the characteristic point. Therefore, it is easy to specify a desired point in a unit smaller than the pixel interval of the original image.

In the enlarged image output to the LCD 14, vertical stripe noise as shown in FIG. FIG. 14B shows an example (solid line) of the luminance signal output to the display means when the original image has the luminance indicated by the dotted line. Conventionally, the entire video output to the LCD 14 is filtered to reduce or eliminate noise on the enlarged image. However, since the filter is applied to video other than the enlarged image, there is a problem that the video is blurred. In the endoscope apparatus according to the present embodiment, only the enlarged image generated as described above is filtered to reduce or eliminate noise that appears in the enlarged image. As the filter, for example, an operation for reducing the rate of change in the signal of the enlarged image, and the following can be applied.
(A) A filter that sets the luminance of each pixel to a weighted average with the pixel on the right of the pixel, that is, L _A (x, y) = p × L _B (x, y) + q × L _B (x + 1) , Y)
However, p + q = 1
As an example, p = q = 1/2 (arithmetic mean)
(B) _A filter that sets the luminance of each pixel as a weighted average of the right adjacent pixel and the left adjacent pixel, that is, L _A (x, y) = p × L _B (x−l, y ) + Q × L _B (x, y) + r × L _B (x + 1, y)
However, p + q + r = 1
As an example, p = r = 1/4, q = 1/2 (weighted average)
Or p = r = 0.274, q = 0.552 (Gaussian function f (x) = exp (−x ^ 2 / 2σ), σ = 1, normalized Gaussian filter)
However, L _B (x, y) represents the luminance value of the image before the filtering process, L _A (x, y) represents the luminance value of the image after the filtering process, and (x, y) represents the position of the pixel in the image. .

  FIG. 14C is an enlarged image when the filter (B) (p = r = 1/4, r = 1/2) is applied, and vertical stripe noise is reduced. FIG. 14D shows an example in which the filter (B) is applied to the original image in FIG. The dotted line and the solid line in the figure respectively indicate the brightness of the enlarged image to which the filter is applied and the brightness signal output to the display means.

  Therefore, according to this example, the unit of movement amount of the sampling point can be arbitrarily set more finely than the original image, and the measurement point can be designated with high accuracy not depending on the enlargement magnification as in the prior art. Further, in the process of moving the sampling points, it is easy to understand the change in the enlarged image, and it is easy to move to a desired measurement point.

  Further, by selecting an appropriate interpolation algorithm, it is possible to improve the visibility of the enlarged image and to easily specify the measurement point. Further, the magnification can be displayed at a desired magnification that is easy to see by not only an integral multiple but also a real number.

  In the above description of the embodiment, the turbine blade chip that is an engine part of the aircraft has been described. However, the measurement endoscope apparatus of the present invention is used for measuring scratches and chips of other various device parts. Can do.

It is a figure explaining the endoscope apparatus for measurement of this embodiment. It is a block diagram explaining the structure of the endoscope apparatus for measurement. It is a figure explaining a remote controller. It is a perspective view which shows the structure which attached the direct-viewing type stereo optical adapter to the endoscope end part for measurement. It is AA sectional drawing of FIG. It is a figure which shows the method of calculating | requiring the three-dimensional coordinate of a measurement point by stereo measurement. (A) is a flowchart for explaining the flow of measurement by the measuring endoscope apparatus, (b) is a flowchart for explaining measurement point designation, and (c) is a flowchart for explaining setting of an enlarged region. (D) is a flowchart for explaining enlarged image generation processing, and (e) is a flowchart for explaining the movement of sampling points. (A) is a figure which shows two right-and-left original images read, (b) is a figure which shows the measurement screen at the time of pointing near a measurement point and displaying an enlarged image, (c) These are figures which show the measurement screen containing the enlarged image at the time of moving a sampling point, (d) is a figure which shows the measurement screen when changing magnification to 6 times, (e) FIG. 5 is a diagram showing a measurement screen when the unit of the moving amount of the sampling point is set to the pixel interval of the original image and the enlargement magnification is changed to 6.times., (F) is a diagram showing the measurement screen; g) is a diagram showing a measurement screen including a measurement result when a distance between two points is measured. It is a figure which shows the enlarged image of the sampling point movement image produced | generated by linear interpolation. (A) is a figure which shows the original image of 6 horizontal pixels x 1 vertical pixel, (b) is a figure which shows the brightness | luminance in the sampling point of an original image, (c) is the brightness | luminance of a sampling point moving image. (D) is a figure which shows the brightness | luminance in the sampling point of the original image at the time of increasing the number of pixels for expansion, (e) is an enlarged image from the brightness | luminance information of (d). FIG. It is a figure which shows the sampling point in the original image, and the moved sampling point. It is a figure which shows an example of the original image of a measuring object. It is a figure which shows the simple expansion image of the expansion area | region of FIG. (A) is a figure which shows the case where the noise of a vertical stripe appears in an enlarged image, (b) is a figure which shows the example of the luminance signal in this case. Moreover, (c) is a figure which shows the example in which the noise at the time of applying a filter is reduced, (d) is a figure which shows the example of the luminance signal in this case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Endoscope for measurement 11 ... Endoscope insertion part 12 ... Control unit 13 ... Remote controller 14 ... Liquid crystal monitor (LCD)
17 ... Face Mount Display (FMD)
18 ... FMD adapter 19 ... speaker 20 ... microphone 21 ... personal computer 22 ... compact flash (registered trademark) memory card 23 ... PCMCIA memory card (PMCIA memory card)
24 ... Endoscope unit 25 ... Camera control unit (CCU)
26 ... CPU
27 ... ROM
28 ... RAM
29 ... RS-232C interface (RS-232C I / F)
30 ・ ・ ・ PC card interface (PC card I / F)
31 ... USB interface (USB I / F)
32 ... Audio signal processing circuit 33 ... Video signal processing circuit 34, 35 ... Objective lens system 36 ... Illumination lens 37 ... Stereo optical adapter 38 ... Fixing ring 39 ... Internal view Mirror tip 43 ... Individual imaging device 43a ... Signal line 53 ... Female screw 54 ... Male screw 61 ... Joystick 62 ... Lever switch 63 ... Freeze switch 64 ... Store switch 65 ... Measurement execution switch 66 ... WIDE switch for enlarged display switching 67 ... TELE switch 70 ... External video input terminal

Claims (4)

An original image acquisition unit that acquires an image sampled and read in pixel units as an original image, and a resampled image generation unit that generates an image by sampling at a predetermined position with respect to a part or all of the region of the original image In an endoscope apparatus for measurement having
Sampling point moving means for moving sampling points corresponding to each pixel in a part or all of the area of the original image in the resampled image generating means, in units smaller than the pixel interval of the original image;
Measuring point position specifying means for specifying the position of the measuring point on the original image in units smaller than the pixel interval of the original image by moving the sampling point to a desired point by the sampling point moving means;
Based on the position of the designated measurement point, measurement means for measuring in units finer than the pixel interval of the original image,
An endoscope apparatus for measurement, comprising: Sampling point moving image generating means for generating an image in which the sampling point has been moved by the sampling point moving means;
An enlarged image generating means for enlarging the sampling point moving image to generate an enlarged image;
An enlarged image display means for displaying an enlarged image;
Measuring point position specifying means for specifying the position of the measuring point on the enlarged image;
The endoscope apparatus for measurement according to claim 1, further comprising:   The measuring endoscope apparatus according to claim 1, further comprising sampling point movement amount unit designation means for designating a unit of movement amount of the sampling point moved by the sampling point movement means. 3. The measuring endoscope apparatus according to claim 2, further comprising a filter unit that performs a filtering process on an enlarged image displayed on the enlarged image display unit.