JP5113990B2 - Endoscope device for measurement - Google Patents

Description

The present invention relates to endoscopes KagamiSo location for measurement was allow three-dimensional measurement, in particular, to those can view the distance to the subject in real time.

  In recent years, endoscopes that can observe various organs in a body cavity by inserting an elongated insertion part into a body cavity or perform various therapeutic treatments using a treatment instrument inserted into a treatment instrument channel as necessary are widely used. Has been. Also in the industrial field, industrial endoscopes are widely used for observing and inspecting internal scratches and corrosion of boilers, turbines, engines, chemical plants, and the like.

  The endoscope used as described above includes an electronic endoscope (hereinafter abbreviated as an endoscope) in which an imaging element such as a CCD that photoelectrically converts an optical image into an image signal is disposed at the distal end portion of an insertion portion. is there. In this endoscope, an image signal of an observation image formed on an image sensor is generated as a video signal by an image processing unit, and the video signal is output to a monitor to display an endoscopic image on the screen for observation. Can be done.

  In particular, in an industrial endoscope, a plurality of types of optical adapters are prepared so that observation can be performed according to the examination location, and can be detachably attached to the distal end portion of the endoscope insertion portion as necessary. It is like that. As an optical adapter, as shown in Patent Document 1 and Patent Document 2, there is a stereo optical adapter in which two observation fields on the left and right are formed in an observation optical system.

  The stereo optical adapter that forms the left and right observation fields as described above uses the principle of triangulation based on the coordinates of the left and right optical systems when the same subject image is captured by the left and right optical systems. The three-dimensional space coordinates of the subject are obtained.

  That is, FIG. 12 is a diagram showing a right-to-left two-image positional relationship on a three-dimensional coordinate system having x, y, and z axes, and the distance measurement point P to be measured is the right imaging plane 101R of the image sensor. A state in which an image is formed on the left imaging surface 101L is shown. In FIG. 12, points OR and OL are the principal points of the optical system, distance f is the focal length, points QR and QL are the imaging positions of point P, and distance L is the distance between point OR and point OL. To do.

In FIG. 12, the following equation is established from the straight line QR-OR. That is,
x / xR = {y− (L / 2)} / {yR− (L / 2)} = z / (− f) (1)
Further, the following equation is established from the straight line QL-OL. That is,
x / xL = {y + (L / 2)} / {yL + (L / 2)} = z / (− f) (2)
Solving this equation for x, y, z gives the three-dimensional coordinates of point P.

  In such 3D measurement, as the distance from the subject to be measured increases, the resolution in the depth direction decreases and the measurement accuracy decreases. For this reason, in order to perform highly accurate three-dimensional measurement, it is necessary to approach the subject to some extent.

  However, in an apparatus such as an endoscope, an optical system having a deep subject depth is used so that a good observation image can be obtained, and it is difficult for an operator to check the situation around the distal end of the insertion portion. For this reason, it is difficult to determine whether or not the object is approached until sufficient measurement accuracy is obtained until the three-dimensional measurement function is activated and a measurement point is designated.

Thus, it is conceivable to display the distance of the subject on the live imaging screen. If the distance of the subject is displayed on the live imaging screen, the operator can determine whether or not a high-accuracy 3D measurement image can be acquired by looking at the distance to the subject. It is possible to switch to three-dimensional measurement after sufficiently approaching a position where an image for three-dimensional measurement can be acquired.
JP 2004-33478 A JP 2004-49638 A

  However, in order to measure the distance to the subject, it is necessary to capture the left and right images, correct the distortion of the image, search for the corresponding points of the distance measuring points, and calculate the spatial coordinates. In order to capture all the left and right images, capture time is required. In addition, when the corresponding points are searched for all the images, the calculation processing for matching becomes enormous. For this reason, with a normal CPU, the processing time is long, and it is difficult to display the distance to the subject in real time. In order to display the distance to the subject in real time, it may be possible to use a high-speed CPU. However, if a high-speed CPU is used, there is a problem that the cost increases and the power consumption increases.

In view of the above-mentioned problems, the present invention can measure the distance to the subject at high speed, and can display the distance to the subject in a live image in real time without using a high-speed CPU. an object of the present invention is to provide a KagamiSo location.

According to the first aspect of the present invention, an electronic endoscope having an image pickup unit for picking up a subject image by a stereo optical system , and connected to the electronic endoscope, receives an image pickup signal from the image pickup unit and receives a video signal. image processing unit that generates, and a control device with a control unit having a measurement processing portion that performs measurement processing as a stereo image input image based on the video signal generated by the image processing unit, the control unit of the control device In a measurement endoscope apparatus including a display device that receives an output image output based on an instruction and displays the image, the control device applies an aim that represents a distance measuring point to a predetermined coordinate on the output image. Based on the coordinates of the distance measurement point to be displayed and the coordinates of the distance measurement points, the range near the distance measurement point on one side of the stereo image and the range near the epipolar line corresponding to the distance measurement point on the other side of the stereo image image An image acquisition area calculation processing unit for obtaining the image acquisition area information to capture range, the portion based on the image acquisition area information, and acquires the respective partial images of the scope and near the epipolar line of the distance measuring point near the stereo image An image acquisition processing unit, a partial distortion correction processing unit that performs distortion correction processing of each partial image obtained by the partial image acquisition processing unit, and a partial image acquisition processing unit that has undergone distortion correction processing by the partial distortion correction processing unit And a distance measurement processing unit that calculates the object distance of the subject at the distance measurement point based on the principle of triangulation using each partial image obtained by the above.

The invention of claim 2 is characterized in that the control device further comprises an aiming position operating means for changing the aiming position and an aiming coordinate acquisition processing unit for obtaining aiming coordinates.

According to a third aspect of the present invention, the control device further includes an out-of-range distance measurement stop means for canceling the distance measurement processing when the screen coordinates of the distance measurement points are outside the predetermined measurable area, and a boundary between the measurable areas. The present invention is characterized by comprising measurable area boundary display means for displaying in an output image.

According to a fourth aspect of the present invention, the control device further includes an object distance display processing unit that displays information on the object distance calculated by the distance measurement processing unit on an output image.
The invention according to claim 5 is characterized in that the object distance display processing unit displays information of the object distance in a bar graph .

  According to the present invention, an aim representing a distance measuring point is displayed at a predetermined coordinate on the observation image of the subject, an observation image is acquired using the center of the aim as a distance measuring point, and the object distance of the subject at the distance measuring point is obtained. Calculation is based on the principle of triangulation. At this time, for the left image, for example, only the image in the vicinity of the distance measuring point is captured, and for the right image, for example, only the image around the epipolar line is captured. In this way, by taking in only the image portion necessary for distance measurement and performing the matching calculation using only the image of the portion necessary for distance measurement, the time taken in and the time required for matching processing are reduced. Accordingly, the distance to the subject can be measured at high speed without using a high-speed CPU, and can be displayed on a live image in real time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows an overall configuration of an endoscope apparatus according to the present invention. As shown in FIG. 1, an endoscope apparatus 1 according to the present embodiment is a control device that includes an endoscope 2 having an elongated insertion portion 20 and a storage portion that stores the insertion portion 20 of the endoscope 2. A control unit 3, a remote controller 4 that performs operations necessary for performing various operation controls of the entire apparatus, and a display device that displays an endoscopic image, operation control content (for example, a processing menu described later), and the like. A liquid crystal monitor (hereinafter referred to as LCD) 5, a normal endoscopic image, or a face-mounted display (hereinafter referred to as FMD) 6 that enables stereoscopic viewing of the endoscopic image as a pseudo stereo image, The FMD adapter 6a for supplying image data to the FMD 6 is mainly configured.

  The insertion portion 20 is configured by connecting a hard distal end portion 21 in order from the distal end side, for example, a bending portion 22 (FIG. 2) that can be bent vertically and horizontally, and a flexible tube portion having flexibility. Various optical adapters such as stereo optical adapters 7a and 7b having two observation fields or a normal observation optical adapter 7c having one observation field are detachable.

  As shown in FIG. 2, the control unit 3 includes an endoscope unit 8, a camera control unit (hereinafter referred to as CCU) 9 as an image processing unit, and a control unit 10 as a control unit. The proximal end portion of 20 is connected to the endoscope unit 8.

  The endoscope unit 8 includes a light source device (not shown) that supplies illumination light necessary for observation, and a bending device (not shown) that bends the bending portion 22 that constitutes the insertion portion 20.

  The CCU 9 receives an imaging signal output from the solid-state imaging device 2 a built in the distal end portion 21 of the insertion unit 20. This imaging signal is converted into a video signal such as an NTSC signal in the CCU 9 and supplied to the control unit 10.

  In the control unit 10, an audio signal processing circuit 11, a video signal processing circuit 12 to which video signals are inputted, a ROM 13, a RAM 14, a PC card interface (hereinafter referred to as PC card I / F) 15, a USB interface (hereinafter referred to as USB) 16) and an RS-232C interface (hereinafter referred to as RS-232C I / F) 17 and the like, and a CPU 18 that controls the operation by executing these various functions based on the main program. Yes.

  The RS-232C I / F 17 is connected to the CCU 9, the endoscope unit 8, and the remote controller 4 that performs control and operation instructions for the CCU 9, the endoscope unit 8, and the like. As a result, communication necessary for controlling the operation of the CCU 9 and the endoscope unit 8 based on the operation of the remote controller 4 is performed.

  The USB I / F 16 is an interface for electrically connecting the control unit 3 and the personal computer 31. By connecting the control unit 3 and the personal computer 31 via the USB I / F 16, various instruction control such as an endoscope image display instruction and image processing at the time of measurement can be performed on the personal computer 31 side. In addition, it becomes possible to input / output control information and data necessary for various processes between the control unit 3 and the personal computer 31.

  In addition, a so-called memory card which is a recording medium such as a PCMCIA memory card 32 or a compact flash (registered trademark) memory card 33 can be freely attached to and detached from the PC card I / F 15. When the memory card is inserted into the PC card I / F 15, the control processing information or image information stored in the memory card is captured or the data such as control processing information or image information is stored under the control of the CPU 18. You can record to a memory card.

  In the video signal processing circuit 12, a display based on an operation menu that generates a video signal from the CCU 9 under the control of the CPU 18 so as to display a composite image obtained by synthesizing the endoscopic image supplied from the CCU 9 and a graphic operation menu. The signal is combined with the signal and necessary for displaying on the screen of the LCD 5 and supplied to the LCD 5. Further, the video signal processing circuit 12 can simply perform processing for displaying an endoscopic image or an image such as an operation menu alone. Therefore, an endoscopic image, an operation menu image, a composite image of the endoscopic image and the operation menu image, and the like are displayed on the screen of the LCD 5.

  In the audio signal processing circuit 11, an audio signal to be recorded on a recording medium such as a memory card, which is collected and generated by the microphone 34, an audio signal obtained by reproducing the recording medium such as a memory card, or generated by the CPU 18. The audio signal is supplied. In the audio signal processing circuit 11, processing such as amplification processing necessary for reproducing the supplied audio signal is performed and output to the speaker 35. As a result, sound is output from the speaker 35.

  The CPU 18 executes a program stored in the ROM 13 to control various circuit units and the like so as to perform processing according to the purpose, thereby performing operation control of the entire system.

  As shown in FIG. 3, a joystick 41, a lever switch 42, a freeze switch 43, a store switch 44, and a measurement execution switch 45 are provided on one surface of the remote controller 4. A zoom lever 47 is also provided.

  The joystick 41 is a switch for instructing a bending operation of the bending portion 22, and the bending portion 22 is bent by a tilt angle in a direction corresponding to the tilt direction by a tilting operation. The lever switch 42 is a switch for performing a pointer movement operation when performing various menu operations displayed graphically and measurement, and is configured in substantially the same manner as the joystick 41. The freeze switch 43 is a switch related to the LCD 5 display. The store switch 44 is a switch used when a still image is displayed when the freeze switch 43 is pressed and this still image is recorded on a memory card. The measurement execution switch 45 is a switch used when executing measurement software.

  The freeze switch 43, the store switch 44, and the measurement execution switch 45 are configured by adopting, for example, a push-down type in which an on / off instruction is performed by a push-down operation. Reference numeral 46 denotes a connector portion to which an electric cable extending from the FMD adapter 7 is connected. By connecting the electric cable to the connector portion 46, stereo observation can be performed through the FMD 6. The zoom lever 47 is a direction switch that can be tilted forward and backward to control the electronic zoom. When it is tilted to the back, it moves to tele (enlarged), and when it is tilted to the front, it moves to wide (reduced).

  4 and 5 show an example of the configuration of a stereo optical adapter 7a that is one of the optical adapters used in the endoscope apparatus 1 of the present embodiment. As shown in FIGS. 4 and 5, a pair of illumination lenses 51 and 52 and two objective lens systems 53 and 54 are provided on the front end surface of the direct-viewing type stereo optical adapter 7a, as shown in FIG. The internal thread 50a of the fixing ring 50 is integrally fixed by screwing with the external thread 21a formed at the tip portion 21.

  As shown in FIG. 5, two optical images are formed on the imaging surface of the solid-state imaging device 2 a disposed in the distal end portion 21 by the two objective lens systems 53 and 54. Then, the imaging signal photoelectrically converted by the solid-state imaging device 2a is supplied to the CCU 9 through the electrically connected signal line 2b and the endoscope unit 8 to be converted into a video signal. It is supplied to the circuit 12.

  In the endoscope apparatus 1 of the present embodiment, as shown in the following (a1) to (d), optical data of an imaging optical system specific to each endoscope 2 is measured, and the optical data is a recording medium. For example, it is recorded on a memory card (PCMCIA memory card 31, memory card 33, etc.).

The specific optical data mentioned above is
(A1) Geometric distortion correction table of two objective optical systems (a2) Geometric distortion correction table of image transmission optical system (b) Focal length of left and right imaging optical systems (c) Left and right imaging optical systems (D) is the optical axis position coordinates on the images of the left and right imaging optical systems.

The personal computer 31 is connected to the endoscope apparatus 1 after collecting the specific optical data, and various dimensions can be measured by performing the following processes (1) to (5). That is,
(1) Read the optical data (a1) to (d) from the memory card.
(2) The to-be-measured object which is a subject is imaged by the endoscope 2 and an image is captured.
(3) The coordinates of the captured image are transformed based on the optical data (a1) to (d). (Distortion correction)
(4) Based on the coordinate-converted image, the three-dimensional coordinates of an arbitrary point are obtained by matching the imaging data.
(5) Various three-dimensional measurements are performed based on the three-dimensional coordinates.

  In the endoscope apparatus 1 of the present embodiment, the distance from the subject can be displayed on the live screen in real time. Therefore, even when the positional relationship between the camera and the subject cannot be easily recognized, the operator can know the distance to the subject that can be observed on the screen while viewing the live image.

  FIG. 6 shows a distance measurement display screen according to the first embodiment of the present invention. As shown in FIG. 6, the aim 71 is shown in the left image 65. Using this aiming point 71 as a distance measuring point, the distance to the distance measuring point is measured in real time. The distance to the distance measuring point is displayed as a distance display character 72 on the screen 64.

  On the screen 64, the distance to the distance measuring point is graphically displayed as a distance display bar graph 73. As shown in FIG. 7, the distance display bar graph 73 is displayed in three colors of a green bar graph 73g, a yellow bar graph 73y, and a red bar graph 73r. A green bar graph 73g indicates a range in which highly accurate three-dimensional measurement is possible. The yellow bar graph 73y indicates that the accuracy is slightly reduced, but is within a range where three-dimensional measurement is possible. The red bar graph 73r indicates that a satisfactory three-dimensional measurement is impossible.

  Thus, in the endoscope apparatus 1 of the present embodiment, the distance to the subject is displayed on the screen in real time together with the live screen. By looking at the distance to the subject, the operator can determine whether or not a high-precision 3D image can be projected. Can be switched.

Next, a process for displaying the distance to the subject on the screen together with the live screen as described above will be described. As shown in FIG. 12, the points OR and OL are the principal points of the optical system, the distance f is the focal length, the points QR and QL are the imaging positions of the point P, and the distance L is the point OR-point OL. If the distance is between, the following equation is established from the straight line QR-OR.
x / xR = {y− (L / 2)} / {yR− (L / 2)} = z / (− f) (1)
Further, the following equation is established from the straight line QL-OL.
x / xL = {y + (L / 2)} / {yL + (L / 2)} = z / (− f) (2)
If this equation is solved for x, y, and z, the three-dimensional coordinates of the point P are obtained, whereby the distance to the subject is obtained.

  Here, the distance between the principal point OR and the point OL of the optical system and the focal length of the imaging optical system are recorded in advance as optical data. The coordinates of the point QL are the coordinates of the aiming 71 that is used as a distance measuring point. The point QR can be obtained by searching the right image 66 for a point corresponding to the distance measuring point.

  From this, for example, when the left image is used as a reference, the corresponding point (QR) of the right image corresponding to the distance measuring point (QL) in the left image is searched by the matching process, and the corresponding point of the right image is found. Once searched, the distance to the distance measuring point can be obtained by calculating the spatial coordinates using the above formula.

  Here, the left image 65 is used as the reference image, and the aim 71 is displayed on the left image 65, but the right image 66 may be used as the reference image. In this case, the aiming 71 is displayed on the right image 66 side.

  When searching for the right image corresponding to the distance measurement point in the left image by matching processing, if the matching calculation is performed at all points in the right image, it takes time to capture the image, and the processing becomes enormous.

  Therefore, in the embodiment of the present invention, only the image portion necessary for distance measurement is captured, only the image of the portion necessary for distance measurement is corrected for distortion, and matching calculation is performed using the image to obtain the acquisition time and distortion correction. The processing time and time required for matching processing are shortened to enable high-speed processing.

  Specifically, for the left image, only the image near the distance measuring point is captured, and for the right image, only the image around the epipolar line is captured. The matching calculation time is significantly reduced by performing the matching calculation only with the peripheral image of the epipolar line.

  That is, according to the epipolar constraint, when a three-dimensional image is captured by two cameras, a certain point captured by the reference camera is projected onto the epipolar line of the other image. For this reason, it is only necessary to capture only the image near the epipolar line and perform matching only with the image near the epipolar line. In this way, the time required for the image capturing process and the time required for the matching process are significantly reduced as compared with the case where matching is performed by capturing all the images on one screen.

  In general, an image by a lens system has optical distortion. When measurement is performed, this distortion causes a large error. Therefore, coordinate conversion is performed using a geometric distortion correction table. Then, for each pixel of the conversion screen, the luminance data of the four pixels at the coordinates corresponding to the optical geometric distortion on the imaging screen is multiplied by the ratio of the weight tables W1 to W4 to obtain the pixel of the conversion screen pixel. We are looking for luminance data. In such image distortion correction processing, the amount of processing is enormous, and this processing takes time.

  Therefore, in the embodiment of the present invention, the weight coefficient used for the distortion correction processing is converted into an integer by multiplying it by a power of 2 after performing only the distortion correction image. Thereby, multiplication of the weight coefficient can be performed by bit shift, and the time for the distortion correction processing is shortened.

  FIG. 8 is a flowchart showing distance measurement display processing according to the first embodiment of the present invention. In this example, as described above, only the image portion necessary for distance measurement is captured, only the image of the portion necessary for distance measurement is corrected for distortion, and matching calculation is performed using the image to obtain the acquisition time and distortion correction. Time and matching processing are shortened. Further, the time required for the distortion correction process is shortened by performing division for obtaining the luminance by bit shift using the weight coefficient used for the distortion correction process as an integer by multiplying by 2 and using the multiplication of the weight coefficient as an integer operation.

In FIG. 8, when the distance measuring function is activated, an initialization process is performed in step S1. The ranging function is activated by setting the zoom lever 47 to the wide end side under the following activation conditions.
(1) The optical adapter is set to a stereo optical adapter.
(2) Live image display or freeze image display is in progress.
(3) The electronic zoom is at the wide end (the electronic zoom is 1 time).

Then, in step S2, the capture range of the left image and the right image is calculated. As shown in FIG. 9, the left image capturing range is an image in the vicinity of a distance measuring point. In FIG. 9, when the coordinates of the ranging point P are (lx, ly), the left acquisition width is L_WIDTH, and the left acquisition height is L_HEIGHT, the coordinates of the base point SPL of the left image acquisition range LAREA are as follows:
(Lx-L_WIDTH / 2, ly-L_HEIGHT / 2)
It becomes.

  Further, the acquisition range RAREA of the right image is an image in the vicinity of the epipolar line 77 as shown in FIG. A specific method for obtaining the epipolar line 77 is as follows.

  From the optical data, the coordinates of the left reference point OL and the coordinates of the right reference point OR are read. The left reference point OL and the right reference point OR are the coordinates of the same observation target near the optical center, and are set when optical data is produced. The coordinates of the left reference point OL are (olx, ly), and the coordinates of the right reference point OR are (orx, ory).

If the X coordinate of the left end of the right image is rsx, the coordinates (esx, esy) of the start point ES of the epipolar line 77 are
(Esx, esy) = (rsx, ly-oliy + ory)
It becomes. In addition, the coordinates (eex, ey) of the end point EE of the epipolar line are as follows:
(Eex, eyy) = (rsx + R_WIDTH, ly-oliy + ory)
It becomes.

Therefore, if the acquisition height is R_HEIGHT, the coordinates of the base point SPR of the acquisition range RAREA of the right image are
(Esx, esy-R_HEIGHT / 2)
It becomes.

  Note that the method of obtaining the epipolar line is not limited to the above, but may be another method known in the field of general stereo vision.

  In FIG. 8, when the image acquisition range is calculated in step S2, the right image is acquired in step S3 based on the obtained acquisition range, and the left image is acquired in step S4. In step S5, the image distortion correction of the right image portion is performed, and in step S6, the image distortion correction of the left image portion is performed. As the weight tables W1 to W4 in the image distortion correction, an integer obtained by multiplying the weight value by a power of 2 is used, and the division for obtaining the luminance is performed by bit shift.

  When image distortion correction is performed in steps S5 and S6, a point search process corresponding to the distance measuring point is performed in step S7. That is, the aim 71 is displayed on the left image 65 as shown in FIG. Using the center position of the aiming point 71 as a distance measuring point, a template is created. Using this template, correlation is obtained by pattern matching, and a point corresponding to the distance measuring point is searched from the right image 66.

  In step S8, based on the principle of triangulation, spatial coordinates are calculated based on the equations (1) and (2), and the distance of the distance measuring point is obtained. Here, the distance between the principal point OR and the point OL of the optical system and the focal length of the imaging optical system are recorded in the memory card as optical data. The coordinates of the point QL are the coordinates of the aiming point 71 that is assumed to be a distance measuring point, and the point QR is obtained by searching the right image 66 for a point corresponding to the distance measuring point in step S7. be able to.

  In step S9, the object distance to the distance measuring point obtained as described above is displayed on the screen. That is, as shown in FIG. 6, the distance to the subject is displayed as a distance display character 72 on the screen 64. Further, the distance to the subject is displayed as a distance display bar graph 73.

  In FIG. 8, it is determined in step S10 whether or not the distance measurement display process is to be ended. If not, the process returns to step S2. The processes in steps S2 to S10 are repeated until the distance display of the distance measuring points is completed. Thus, the distance of the subject can be displayed in real time in parallel with the live image display (or the freeze screen display). If it is determined in step S10 that the distance measurement display process is to be terminated, the process is terminated.

(Second Embodiment)
FIG. 10 shows a distance measurement display process according to the second embodiment of the present invention. In the first embodiment described above, the aiming 71 is fixed on the screen. On the other hand, in this embodiment, the operator can freely move the aiming 71. The operator can move the aiming 71 up, down, left and right on the screen by operating the lever switch 42 of the remote controller 4. A measurable range 75 is displayed on the screen. If the distance measuring point indicated by the aiming point 71 is within the measurable range 75, distance measurement is possible. Since the position of the left image differs depending on the optical adapter, the coordinates of the measurable range 75 are held as optical data of the memory card.

  FIG. 11 is a flowchart showing the operation of the distance measurement display process according to the second embodiment of the present invention. In FIG. 11, initialization processing is performed in step S101. In step S102, it is determined whether or not the coordinates of the distance measuring point are within the measurable range. If it is within the possible range, an observation image acquisition process is performed in step S103, and the image is developed on the memory.

  In step S104, it is determined whether or not the coordinates of the aiming 71 have changed. If the coordinates of the aiming 71 have changed, the process returns to step S102, and the process starts again from the coordinate range confirmation.

  If the coordinates of the aim 71 have not changed in step S104, the acquisition range of the right image and the left image is calculated in step S105. Specifically, for the left image, an image in the vicinity of the distance measuring point is the acquisition range, and for the right image, an image around the epipolar line is the acquisition range. Then, based on the set acquisition range, an image clipping process for the right image 66 is performed in step S106, and an image clipping process for the left image 65 is performed in step S107.

  In step S108, distortion correction processing of the image of the right image 66 is performed, and distortion correction processing of the image of the left image 65 is performed in step S109. The distortion is corrected using optical data recorded on the memory card.

  In step S110, a point search process corresponding to the distance measuring point is performed. In step S111, the distance between the principal point OR and the point OL of the optical system read from the memory card, the focal length of the imaging optical system, and the point QR obtained by the search processing for the point corresponding to the distance measuring point. From the coordinates of QL and QL, the spatial coordinates are calculated from the principle of triangulation, and the distance of the distance measuring point is obtained.

  In step S112, it is determined whether or not the coordinates of the aiming 71 have changed. If the coordinates of the aiming 71 have changed, the process returns to step S102, and the process starts again from the coordinate range confirmation.

  If the coordinate of the aim 71 has not changed in step S112, the object distance to the distance measuring point obtained as described above is displayed on the screen in step S113.

  In step S114, it is determined whether or not the distance measurement display process is to be ended. If not, the process returns to step S13. Thus, the distance of the subject can be displayed in real time in parallel with the live image display (or the freeze screen display). If it is determined in step S23 that the distance measurement display process is to be terminated, the process is terminated.

  As described above, in this embodiment, when the subject to be measured is at the end of the screen, the aim 71 can be moved by operating the lever switch 42 to aim at the subject to be measured.

  Note that the present invention is not limited to the above-described embodiments, and various modifications and applications are possible without departing from the spirit of the present invention.

The present invention is suitable for use in endoscopes for measurement was allow three-dimensional measurement.

It is a perspective view which shows the structure of the endoscope apparatus which can apply this invention. It is a block diagram explaining the structure of the endoscope apparatus which can apply this invention. It is a perspective view used for description of a remote controller. It is a perspective view which shows the structure of a stereo optical adapter. It is sectional drawing which shows the structure of a stereo optical adapter. It is explanatory drawing of the screen structure of the ranging display which concerns on the 1st Embodiment of this invention. It is explanatory drawing of the bar graph display of distance. It is a flowchart used for description of the ranging display process which concerns on the 1st Embodiment of this invention. It is explanatory drawing of the image acquisition range in the 1st Embodiment of this invention. It is explanatory drawing of the screen structure of the ranging display which concerns on the 2nd Embodiment of this invention. It is a flowchart used for description of the ranging display process which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of the principle of ranging.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus 2 Endoscope 3 Control unit 4 Remote controller 5 Liquid crystal monitor (LCD)
65 Left screen 66 Right screen 71 Aiming 72 Distance display character 73 Distance display bar graph

Claims (5)

An electronic endoscope having an imaging unit for imaging a subject image by a stereo optical system, and an image processing unit connected to the electronic endoscope and receiving an imaging signal from the imaging unit and generating a video signal; And a control device including a control unit having a measurement processing unit that performs a measurement process using a stereo image based on the video signal generated by the image processing unit as an input image, and an output based on an instruction of the control unit of the control device In an endoscope apparatus for measurement comprising a display device that receives an output image to be displayed and displays the image,
The controller is
An aim display processing unit for displaying an aim representing a distance measuring point at predetermined coordinates on the output image;
Based on the coordinates of the ranging point, a range near the ranging point in one of the stereo images and a range near the epipolar line corresponding to the ranging point in the other stereo image are An image acquisition area calculation processing unit for obtaining image acquisition area information as a capture range;
Based on the image acquisition area information, a partial image acquisition processing unit for acquiring a partial image of the range near the distance measurement point and a range near the epipolar line of the stereo image;
A partial distortion correction processing unit that performs distortion correction processing of each of the partial images obtained by the partial image acquisition processing unit;
Using the partial images acquired by the partial image acquisition processing unit that has been subjected to the distortion correction processing by the partial distortion correction processing unit, the object distance of the subject at the distance measuring point is calculated based on the principle of triangulation. An endoscope apparatus for measurement, comprising: a distance measurement processing unit for calculating. The control device further includes:
The measuring endoscope apparatus according to claim 1, further comprising an aiming position operating unit that changes the aiming position and an aiming coordinate acquisition processing unit that obtains the aiming coordinates. The control device further includes:
Out-of-range distance measurement stop means for stopping the distance measurement processing when the screen coordinates of the distance measurement points are outside a predetermined measurable area, and a measurable area boundary for displaying the boundary of the measurable area in the output image The measuring endoscope apparatus according to claim 2, further comprising display means. The control device further includes:
4. The measurement endoscope according to claim 1, further comprising an object distance display processing unit that displays information on the object distance calculated by the distance measurement processing unit on the output image. apparatus.   The measurement endoscope apparatus according to claim 4, wherein the object distance display processing unit displays the object distance information in a bar graph.

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