JP4975417B2 - Endoscope apparatus and endoscope image distortion correction method - Google Patents

Description

  The present invention relates to an endoscope apparatus in which an optical system can be changed by an optical adapter, and relates to an endoscope apparatus and an endoscope image distortion correction method that perform measurement by correcting distortion of an endoscope image.

The distortion of the endoscope image is caused by the distortion of the optical system that combines the endoscope and the optical adapter. As a conventional endoscope apparatus, a technique has been proposed in which distortion of this image is corrected based on optical data including a distortion correction parameter by distortion correction means of the endoscope apparatus (see, for example, Patent Document 1). . The optical data is created by combining the optical adapter and the reference scope by the image processing apparatus in the production process of the optical adapter. This optical adapter and optical data are used in combination with a user scope. The distortion-corrected image is used for measurement, and the more accurate the distortion correction, the more accurate the measurement.
JP 2004-049638 A

  There is a difference in optical characteristics (for example, magnification) between the reference scope and the user scope. Since the optical data is created by the combination of the reference scope and the optical adapter, it does not reflect the characteristics of the user scope. Therefore, the distortion caused by the difference in characteristics cannot be corrected.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is an endoscope that can accurately correct image distortion caused by a difference in optical characteristics between a reference scope and a user scope. A mirror apparatus and an endoscope image distortion correction method are provided.

  In order to solve the above-described problem, the present invention provides an endoscope apparatus in which a part of an optical system can be changed by an optical adapter, and an image input by an optical system in which a reference scope or a user scope and an optical adapter are combined. Imaging means for imaging, optical data for correcting distortion of an optical system combining the reference scope and the optical adapter, a distortion parameter of the reference scope indicating optical characteristics of the reference scope, and the user scope Distortion correction means for correcting distortion of an image captured by the imaging means when the user scope and the optical adapter are combined based on a distortion parameter of the user scope indicating optical characteristics. Features.

  The present invention is characterized in that, in the above-described invention, the image processing apparatus further includes a measurement unit that measures the shape of the subject based on the image whose distortion is corrected by the correction unit.

  According to the present invention, in the above invention, the optical adapter includes an optical element for imaging from a different viewpoint by the imaging unit, and the measuring unit is imaged from a different viewpoint by the imaging unit via the optical element. It is characterized in that the measured image is three-dimensionally measured by triangulation.

  According to the present invention, in the above invention, the optical element has a plurality of optical path systems.

  The present invention is characterized in that, in the above-mentioned invention, the distortion parameter of the reference scope and the distortion parameter of the user scope include magnifications of the respective scopes.

  According to the present invention, in the above invention, the distortion parameter of the reference scope and the distortion parameter of the user scope include a distortion center of each scope.

  In order to solve the above-described problems, the present invention is an endoscope image distortion correction method for correcting distortion of an image captured by an endoscope apparatus in which a part of an optical system can be changed by an optical adapter. A first step of reading optical data for correcting distortion of an optical system combining the reference scope and the optical adapter, and a second step of reading distortion parameters of the reference scope indicating optical characteristics of the reference scope. A third step of reading a distortion parameter of the user scope indicating optical characteristics of the user scope, optical data for correcting distortion of an optical system combining the reference scope and the optical adapter, and the reference A distortion parameter of the reference scope indicating the optical characteristics of the scope, and a user score indicating the optical characteristics of the user scope. Based on the distortion parameters of the flop, characterized in that it comprises a fourth step of correcting the distortion of an image captured by the imaging unit when the combination of said user scope and the optical adapter.

  According to the present invention, in the above invention, when the fourth step fails to read parameters in the second step or the third step, the captured image is based only on the optical data. And a process of correcting the distortion.

  According to the present invention, the optical data for correcting the distortion of the optical system combining the reference scope and the optical adapter by the distortion correction means, the distortion parameter of the reference scope indicating the optical characteristics of the reference scope, and the user scope Based on the distortion parameter of the user scope indicating the optical characteristics of the user scope, the distortion of the image captured by the imaging means when the user scope and the optical adapter are combined is corrected. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  Further, according to the present invention, the shape of the subject is measured by the measuring unit based on the image whose distortion is corrected by the correcting unit. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  In addition, according to the present invention, the measurement unit performs three-dimensional measurement by triangulation of images captured from different viewpoints by the imaging unit via the optical element of the optical adapter. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  According to the invention, the optical element is an element having a plurality of optical path systems. Therefore, a general optical element such as a prism can be used as the optical element, and image distortion caused by a difference in optical characteristics between the reference scope and the user scope can be more accurately performed. There is an advantage that the accuracy of stereo measurement can be improved.

  According to the present invention, the magnification of each scope is included in the distortion parameter of the reference scope and the distortion parameter of the user scope. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  According to the present invention, the distortion center of each scope is included in the distortion parameter of the reference scope and the distortion parameter of the user scope. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  Further, according to the present invention, based on the optical data for correcting the distortion of the optical system of the optical adapter by the distortion correction means, and the distortion parameter of the user scope indicating the optical characteristics of the user scope, The distortion of the image picked up by the image pickup means when combined with the optical adapter is corrected. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  Further, according to the present invention, in the first step, optical data for correcting distortion of an optical system combining the reference scope and the optical adapter is read, and in the second step, the optical characteristics of the reference scope are determined. The distortion parameter of the reference scope shown is read, the distortion parameter of the user scope indicating the optical characteristics of the user scope is read in the third step, and the distortion of the optical system in which the reference scope and the optical adapter are combined in the fourth step. The user scope and optical adapter are combined based on optical data to compensate for, reference scope distortion parameters indicating the optical characteristics of the reference scope, and user scope distortion parameters indicating the optical characteristics of the user scope. In this case, the distortion of the image picked up by the image pickup means is corrected. Therefore, it is possible to more accurately perform image distortion caused by the difference in optical characteristics between the reference scope and the user scope, and it is possible to obtain an advantage that the accuracy of stereo measurement can be improved.

  Further, according to the present invention, when parameter reading fails in the second step or the third step, distortion of the captured image is corrected based on only the optical data in the fourth step. Therefore, even when data is lost or needs to be updated, image distortion caused by the difference in optical characteristics between the reference scope and the user scope can be performed more accurately and quickly. This also has the advantage that the accuracy of stereo measurement can be improved.

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

A. First Embodiment FIG. 1 is a perspective view showing a hardware configuration of an endoscope apparatus 1 according to a first embodiment of the present invention. The endoscope apparatus 1 includes a stereo measurement optical adapter (hereinafter referred to as a stereo optical adapter) 2, an endoscope insertion portion (hereinafter referred to as a scope) 3 in which the stereo optical adapter 2 can be attached to and detached from a distal end portion, A control unit 4 that houses the scope 3, a remote controller 5 for performing various operations control for the entire system of the endoscope apparatus 1, an endoscopic image and operation control contents (for example, processing) It is mainly composed of a liquid crystal monitor (hereinafter referred to as LCD) 6 which is a display device for displaying a menu.

  Next, FIG. 2 is a block diagram showing a configuration of the endoscope apparatus 1 according to the first embodiment. As shown in FIG. 2, the proximal end portion of the scope 3 is connected to the endoscope unit 7. The endoscope unit 7 is accommodated in the control unit 4. The endoscope unit 7 incorporates a light source for obtaining illumination light necessary for photographing and an electric bending device for electrically bending driving a bending portion (not shown) of the scope 3. This electric bending apparatus includes an EEPROM 8 for recording a control parameter for bending driving and a parameter for correcting distortion inherent in the scope optical system (hereinafter, both are referred to as parameters).

  An imaging signal output from an imaging element built in the scope 3 is input to a camera control unit (hereinafter referred to as CCU) 9 that is an image processing unit. The CCU 9 converts the input imaging signal into a video signal such as an NTSC signal, for example, and supplies it to the main circuit group in the control unit 4.

  The main circuit group mounted in the control unit 4 includes a CPU 10, a ROM 11, a RAM 12, and a PC card interface (hereinafter, referred to as a control unit that performs various functions based on a main program and an arithmetic processing unit that performs measurement processing). PC card I / F) 13, USB interface (hereinafter referred to as USB I / F) 14, RS-232C interface (hereinafter referred to as RS-232C I / F) 15, and video signal processing circuit 16. It is configured.

  The RS-232C I / F 13 is connected to the CCU 9, the endoscope unit 7 and the remote controller 5, respectively. The remote controller 5 is for performing control and operation instructions of the CCU 9 and the endoscope unit 7. On the other hand, the RS-232C I / F 15 is for performing communication necessary for controlling the operation of the CCU 9 and the endoscope unit 7 based on the operation by the remote controller 5.

  The USB I / F 14 is an interface for electrically connecting the control unit 4 and a personal computer (hereinafter referred to as a PC) 17. When the control unit 4 and the PC 17 are connected via the USB I / F 14, various instruction controls such as an instruction to display an endoscopic image on the control unit 4 and image processing at the time of measurement are also performed on the PC 17 side. In addition, control information and data necessary for various processes can be input / output between the control unit 4 and the PC 17.

  The PC card I / F 13 is detachably connected to an external storage medium such as a PCMCIA memory card 18 or a Compact Flash (registered trademark) memory card 19. That is, when an external storage medium is loaded, the control unit 12 reproduces data such as control processing information and image information stored in the external storage medium under the control of the CPU 10 and takes in via the PC card I / F 13. Alternatively, data such as control processing information and image information can be supplied and recorded on the memory card via the PC card I / F 13.

  The video signal processing circuit 16 is based on the video signal from the CCU 9 and the operation menu generated by the control of the CPU 10 so as to display a composite image obtained by synthesizing the endoscopic image supplied from the CCU 9 and the graphic operation menu. The display signal is combined with the display signal, and further, processing necessary for display on the screen of the LCD 6 is performed and supplied to the LCD 6. Thereby, a composite image of the endoscope image and the operation menu is displayed on the LCD 6. Note that the video signal processing circuit 16 can simply perform processing for displaying an endoscopic image or an image such as an operation menu alone.

  The CPU 10 executes a program stored in the ROM 11 and controls various circuit units so as to perform processing according to the purpose, thereby controlling the operation of the entire system.

  The remote controller 5 is provided with a joystick, a lever switch, a freeze switch, a store switch, a measurement execution switch, and the like (not shown) at least on the upper surface.

  It is assumed that the endoscope apparatus 1 shown in FIGS. 1 and 2 has the same hardware configuration in all of the other embodiments described below including the first embodiment.

  Next, FIG. 3 is a conceptual diagram showing a schematic configuration of the optical system of the stereo optical adapter 2 and the scope 3 according to the first embodiment. In the figure, a stereo optical adapter 2 is for inputting two images with parallax necessary for performing stereo measurement, and includes a pair of left and right objective optical systems 2a and an adapter side image transmission optical system 2b. And is mainly composed. Further, the scope 3 is for inserting an image at a location where observation is desired, and is mainly composed of an endoscope side image transmission optical system 3a and an imaging element 3b. It is assumed that the optical system of the scope 3 shown in FIG. 3 has the same configuration in all other embodiments described below including the first embodiment.

Next, FIG. 4 is a conceptual diagram for explaining a method of calculating three-dimensional coordinates by stereo measurement according to the first embodiment. The coordinates of the measurement points on the image input in the left and right optical systems of the scope 3 are respectively (X _L , Y _L ) and (X _R , Y _R ), and the three-dimensional coordinates of the measurement points are (X, Y, Z). When the distance between the left and right optical centers is D and the focal length is F, X, Y, and Z are expressed by the following equation (1) by the triangulation method.

However, in the above mathematical formula (1), t = D / (X _L −X _R ). In normal measurement, when the user inputs the coordinates (X _L , Y _L ) of the measurement point on the left image, the coordinates (X _R , Y _R ) on the right image corresponding to this point are automatically existing. The three-dimensional coordinates of the input measurement point are calculated by obtaining the template matching method. In order to perform stereo measurement, in addition to the parameters such as the optical center distance D and the focal length F, it is necessary to measure optical data for correcting distortion of the stereo optical adapter and the scope optical system, and scope distortion parameters. There is.

  Next, FIG. 5 is a block diagram for explaining a method of measuring optical data of the stereo optical adapter according to the first embodiment. The optical data is measured by attaching the stereo optical adapter 2 to a reference scope 23 mounted on a reference endoscope 22 that is a production measuring jig 21 in the production process, imaging a grid-like chart 24, and taking the image data. Is performed by the PC 25 based on the above. Here, details of the optical data are shown in the following (a) to (d).

(A) Geometric distortion correction coefficient of two objective optical systems (b) Focal length F of the two objective optical systems
(C) The distance D between the optical axes of the two objective optical systems
(D) Position information of the two images with respect to the master

  Next, FIG. 6 shows (e) distortion parameters of the reference scope 23 and (f) distortion parameters of the user scope 27 mounted on an endoscope 26 (hereinafter referred to as user endoscope) actually used by the user. It is a block diagram for demonstrating the measuring method. The configuration shown in FIG. 6 is a jig for measuring the distortion parameter of the user scope 27. In a state where the stereo optical adapter 2 is not attached to the user scope 27, the grid chart 28 is imaged from a predetermined distance. The PC 25 captures the image data and obtains the distortion parameter (f) of the user scope 27 by image processing. Note that the distortion parameter to be measured includes the distortion center and the magnification. The measured distortion parameters of the user scope 27 are recorded in the EEPROM 28 mounted on the user endoscope 26. Although not specifically shown, the method (e) of measuring the distortion parameter of the reference scope 23 is the same as that of the user scope 27 described above.

  Returning to FIG. 5, the optical data (a) to (d) and (e) the distortion parameter of the reference scope 23 are recorded as the optical data card 29 in the memory card. As a result, the optical data card 29 and the stereo optical adapter 2 have a one-to-one correspondence.

  After measuring the optical data, by attaching the stereo optical adapter 2 to the user scope 27, the user endoscope 26 can perform stereo measurement by the following processes (1) to (9).

(1) Read the optical data (a) to (d) and (e) the distortion parameter of the reference scope 23 from the optical data card 29.
(2) A white subject is imaged by the user endoscope 26.
(3) Using the optical data of (a) to (d) and the image data captured in (2), the displacement of the image position due to the combination of the stereo optical adapter 2 and the user scope 27 is obtained.
(4) Using (e) the distortion parameter of the reference scope 23 and the distortion parameter of the user scope 27 read from the EEPROM 28, the difference from the distortion parameter of the reference scope 23 is obtained.

(5) Using the data of (3) and (4), the optical data is corrected and a conversion table for correcting distortion between the stereo optical adapter 2 and the user scope 27 is created. The optical data and the conversion table are recorded as an environmental data card on a memory card (not shown).
(6) The measurement subject 30 is imaged by the user endoscope 26.
(7) Based on the conversion table created in the above (5), the image captured in the above (6) is subjected to coordinate conversion.
(8) Based on the image subjected to the coordinate conversion in (7), the three-dimensional coordinates of an arbitrary point are obtained by the method described above.
(9) Perform stereo measurement based on the three-dimensional coordinates obtained in (8) above.

  In the second and subsequent stereo measurements, the environmental data card created in the above (5) may be read, so the processes (1) to (5) are omitted.

Here, the distortion correction method in the first embodiment will be described. This distortion correction method is a combination of the first distortion correction for correcting distortion of the objective optical system 2a in FIG. 3, and the adapter side image transmission optical system 2b and the endoscope side image transmission optical system 3a. It consists of the second distortion correction for correcting the distortion of the transmission optical system. These distortion corrections are performed by coordinate transformation. Coordinate conversion between the first distortion correction and the second distortion correction is expressed by the following mathematical formulas (2) to (13).
<Second distortion correction>

<First distortion right correction>

<First distortion left correction>

However, in the formulas (2) to (13),
x, y: coordinates before correction x _R ', y _R ': right screen coordinates after correction x _L ', y _L ': left screen coordinates after correction c _2x , c _2y : second distortion center coordinates c _Rx , c _Ry : the first strain right center coordinates _{c Lx, c Ly:} first distortion left center coordinates _{k 2x, k 2y, a 2ij} , b 2ij: second distortion correction coefficient _{k Rx, k Ry, a Rij} , b Rij: first distortion Right correction coefficients k _Lx , k _Ly , a _Lij , b _Lij : First distortion left correction coefficients.

Note that the _k-factor excluding k of _2x such _{a 2ij, b 2ij, a Rij} , a Lij, b Lij, c 2x, c 2y, c Rx, c Ry, c Lx, c Ly is the linearity of the grating image Ask more. Further, k _2x , k _2y, etc. are functions for adjusting the magnifications of the two images and are functions of the focal lengths f _R and f _L.

These parameters are included in the optical data created by combining the reference scope 23 and the stereo optical adapter 2. In order to correct the difference between the reference scope 23 and the user scope 27, multiplied by _m m / _{m u} coefficient _k x, _{k y} corresponding to the magnification of the synthetic image transmitting optical system (where, _{m m} is the reference scope 23 the magnification, _{m u} magnification of user scope 27), coordinates _c x corresponding to the distortion center of the composite image transmitting optical system, a _{c y c mx, c my,} c ux, c uy ( _however, c _{mx, c my} Is corrected based on the distortion center of the endoscope side image transmission optical system of the reference scope 23, and c _ux and c _ui are the distortion center of the endoscope side image transmission optical system of the user scope 27). As a result, distortion correction can be performed more accurately, and the accuracy of stereo measurement can be improved.

A ′: Modification of First Embodiment Next, a modification of the first embodiment of the present invention will be described. The distortion correction method in the present modification includes a first distortion correction for correcting distortion of the objective optical system 2a in FIG. 3, a second distortion correction for correcting distortion of the adapter-side image transmission optical system 2b, This includes third distortion correction for correcting distortion of the endoscope side image transmission optical system 3a.

  The coordinate transformation for the first distortion correction is the same as in equations (6) to (13). The coordinate transformation for the third distortion correction is as shown in the following formulas (14) to (17).

  The coordinate transformation for the third distortion correction is as shown in equations (2) to (3) and equations (18) to (19) shown below.

However, in the equations (14) to (19),
c _3x , c _3y : third distortion center coordinates k _3x , k _3y , a _3ij , b _3ij : third distortion correction coefficients.

  The specific procedure for distortion correction in this modification is as follows. First, optical data is measured after correcting the distortion of the optical system of the reference scope 23. That is, as shown in FIG. 5, the reference scope based on the equations (14) to (17) is obtained for image data obtained by attaching the stereo optical adapter 2 to the reference scope 23 mounted on the reference endoscope 22. Then, the optical data is measured based on the image data after correcting the distortion. The measured optical data is recorded on the optical data card 29.

  The third distortion center coordinates and the third distortion correction coefficient in the mathematical expressions (14) to (17) are distortion parameters of the reference scope 23. The distortion parameters of the reference scope 23 are measured in advance by the same method as described above and recorded on the optical data card 29. The optical data measured based on the image data in which the distortion of the optical system of the reference scope 23 is corrected is composed of parameters for correcting the distortion of only the stereo optical adapter 2. First distortion center coordinates (first distortion right center coordinates, first distortion left center coordinates), first distortion correction coefficients (first distortion right correction coefficients, first distortion left correction coefficients), second distortion center coordinates, Two distortion correction coefficients are included in this optical data.

  In the user endoscope 26 in which the stereo optical adapter 2 is attached to the user scope 27, distortion correction can be performed as follows. The distortion parameter of the user scope 27 is measured in advance by the same method as described above, and is recorded in the EEPROM 28. The distortion parameters of the user scope 27 include third distortion center coordinates and a third distortion correction coefficient. The distortion parameter of the user scope 27 is read from the EEPROM 28, and the third distortion correction can be performed based on this and the mathematical expressions (14) to (17).

  Further, the optical data is read from the optical data card 29, and the first distortion correction and the second distortion correction are performed based on this and the mathematical expressions (2) to (3), (6) to (13), and (18) to (19). It can be performed. According to the distortion correction method of this modification, it is possible to correct the distortion of an image more accurately than the distortion correction method of the first embodiment described above.

B. Second Embodiment Next, a second embodiment of the present invention will be described.
FIG. 7 is a block diagram for explaining a method of measuring optical data of the stereo optical adapter according to the second embodiment. The endoscope apparatus according to the second embodiment includes a stereo optical adapter 31 as shown in FIG. 8, and the rest is the same as that of the first embodiment. That is, the stereo optical adapter 31 of the second embodiment is configured by one prism-shaped objective optical system 31a and adapter-side image transmission optical system 31b in order to input two images with parallax. .

  As shown in FIG. 9, the same subject is imaged from different viewpoints by the prism-shaped objective optical system 31a and the image transmission optical system (the endoscope side image transmission optical system 3a and the adapter side image transmission optical system 31b). be able to. Even when such an optical system is used, by correcting the optical data based on the difference between the reference scope 23 and the user scope 27, distortion correction can be performed more accurately, and the accuracy of stereo measurement is improved. be able to.

C. Third Embodiment Next, a third embodiment of the present invention will be described.
FIG. 10 is a block diagram for explaining a method of measuring optical data of the stereo optical adapter according to the third embodiment. In the endoscope bond according to the third embodiment, a barcode 32 describing the ID of the user scope 7 is provided in the user scope 27, and the distortion parameters of the user scope 27 are referred to from the distortion parameter database 33 and recorded in the EEPROM 28. It is configured as follows. Others are the same as in the first embodiment.

Data recorded in the EEPROM 28 may be lost due to electrical noise or other failures. In addition, when the scope itself must be replaced due to damage of the scope or the like, it is necessary to update the data recorded in the EEPROM 28. In order to record the data again in such a case, the data is recorded with reference to a ledger of distortion parameters measured in the past.
・ Measure and record the distortion parameters again.
However, there are problems such as spending time referring to past data and taking time to measure again.

Therefore, in the third embodiment, this problem is solved by the following method.
(1) A barcode 32 describing the ID of the user scope 27 is attached to the user scope 27.
(2) When writing to the EEPROM 28 is necessary, the distortion parameter of the corresponding user scope 27 is read from the distortion parameter database 33 based on the barcode ID. The distortion parameter database 33 is a database that records distortion parameters measured when the user scope 27 is produced.
(3) The distortion parameter is recorded in the EEPROM 28.

  Thus, even if the data in the EEPROM 28 has been lost or needs to be updated, the data can be recorded easily and in a short time by referring to the distortion parameter database 33. Instead of the barcode 32, an ID tag that records the ID of the user scope 27 may be used.

D. Fourth Embodiment Next, a fourth embodiment of the present invention will be described.
FIG. 11 is a block diagram for explaining a method of measuring optical data of the stereo optical adapter according to the fourth embodiment. As shown in FIG. 11, the endoscope apparatus according to the fourth embodiment affixes a print sheet 34 describing the distortion parameters of the user scope 27 to the user scope 27, and the EEPROM 28 by the distortion parameter input device 35 of the user scope 27. It is configured to record. Others are the same as in the first embodiment.

As described above, the data recorded in the EEPROM 28 may be lost due to electrical noise or other failures. Further, when the scope itself needs to be replaced due to damage of the scope or the like, it is necessary to update the data recorded in the EEPROM 28. In order to record the data again in such a case, the data is recorded with reference to a ledger of distortion parameters measured in the past.
・ Measure and record the distortion parameters again.
However, there are problems such as taking time to refer to past data and taking time to measure again.

Therefore, in the fourth embodiment, this problem is solved by the following method.
(1) A print sheet 34 describing distortion parameters of the user scope 27 is attached to the user scope 27.
(2) When writing in the EEPROM 28 is necessary, the distortion parameter is recorded in the EEPROM 28 by the input device 35 based on the print sheet 34.

  As a result, when the data in the EEPROM 28 is lost or needs to be updated, the data can be easily and quickly obtained by referring to the print sheet 34 describing the distortion parameters of the user scope 27 measured previously. Can be recorded.

  According to the first to fourth embodiments described above, it is possible to more accurately correct image distortion caused by a difference in optical characteristics between the reference scope and the user scope. This also improves the accuracy of stereo measurement.

  In the above-described embodiment, the series of processes performed by the CPU 10 described above is stored in a computer-readable recording medium in the form of a program, and the program is read out and executed by the computer. Is done. That is, each processing means and processing unit in the CPU 10 is realized by a central processing unit such as a CPU reading the above program into a main storage device such as a ROM or a RAM and executing information processing / calculation processing. Is.

  Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

It is a perspective view showing hardware constitutions of endoscope apparatus 1 by a 1st embodiment of the present invention. It is a block diagram which shows the structure of the endoscope apparatus 1 by this 1st Embodiment. It is a conceptual diagram which shows the schematic structure of the optical system of the stereo optical adapter 2 and the scope 3 by this 1st Embodiment. It is a conceptual diagram for demonstrating the calculation method of the three-dimensional coordinate by stereo measurement by this 1st Embodiment. It is a block diagram for demonstrating the measuring method of the optical data of the stereo optical adapter by this 1st Embodiment. FIG. 6 is a block diagram for explaining a method of measuring a distortion parameter of a reference scope 23 and a distortion parameter of a user scope 27 in the first embodiment. It is a block diagram for demonstrating the measuring method of the optical data of the stereo optical adapter by this 2nd Embodiment. It is a conceptual diagram which shows the schematic structure of the optical system of the stereo optical adapter 2 and the scope 3 by this 2nd Embodiment. It is a conceptual diagram for demonstrating the calculation method of the three-dimensional coordinate by stereo measurement by this 2nd Embodiment. It is a block diagram for demonstrating the measuring method of the optical data of the stereo optical adapter by this 3rd Embodiment. It is a block diagram for demonstrating the measuring method of the optical data of the stereo optical adapter by this 4th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Endoscope apparatus 2 Stereo optical adapter 2a Objective optical system 2b Adapter side image transmission optical system 3 Scope 3a Endoscope side image transmission optical system 3b Image sensor (imaging means) 4 Control unit 5 Remote controller 7 Endoscope unit 8 EEPROM 9 CCU 10 CPU (distortion correcting means, measuring means) 11 ROM 12 RAM 13 PC card I / F 14 USB I / F 15 RS-232C I / F 16 Video signal processing circuit 17 PC 18 PCMCIA memory card 19 Compact flash ( Registered Trademark) Memory Card 21 Production Measurement Jig 22 Reference Endoscope 23 Reference Scope 24, 28 Chart 25 PC 26 User Endoscope 27 User Scope 28 EEPROM 29 Optical Data Card 31 Stereo optical adapter 31a Objective optical system (optical element) 31b Adapter side image transmission optical system 32 Bar code 33 Distortion parameter database 34 Print sheet

Claims (8)

In an endoscope apparatus in which a part of the optical system can be changed by an optical adapter,
An imaging means for capturing an image input by an optical system in which a reference scope or user scope and an optical adapter are combined;
Optical data for correcting distortion of an optical system combining the reference scope and the optical adapter, a distortion parameter of a reference scope indicating optical characteristics of the reference scope, and a user indicating optical characteristics of the user scope An endoscope, comprising: a distortion correction unit that corrects distortion of an image captured by the imaging unit when the user scope and the optical adapter are combined based on a distortion parameter of a scope. apparatus.   The endoscope apparatus according to claim 1, further comprising a measuring unit that measures a shape of a subject based on an image whose distortion is corrected by the correcting unit. The optical adapter includes an optical element for imaging from different viewpoints by the imaging means,
The endoscope apparatus according to claim 2, wherein the measuring unit performs three-dimensional measurement by triangulation of images captured from different viewpoints by the imaging unit via the optical element.   The endoscope apparatus according to claim 3, wherein the optical element has a plurality of optical path systems.   The endoscope apparatus according to claim 1, wherein the distortion parameter of the reference scope and the distortion parameter of the user scope include magnifications of the respective scopes.   The endoscope apparatus according to claim 4, wherein the distortion parameter of the reference scope and the distortion parameter of the user scope include a distortion center of each scope. An endoscope image distortion correction method for correcting distortion of an image captured by an endoscope apparatus in which a part of an optical system can be changed by an optical adapter,
A first step of reading optical data for correcting distortion of an optical system combining a reference scope and the optical adapter;
A second step of reading a distortion parameter of the reference scope indicating optical characteristics of the reference scope;
A third step of reading user scope distortion parameters indicative of optical characteristics of the user scope;
Optical data for correcting distortion of an optical system combining the reference scope and the optical adapter, a distortion parameter of a reference scope indicating optical characteristics of the reference scope, and a user indicating optical characteristics of the user scope And a fourth step of correcting distortion of an image picked up by the image pickup means when combining the user scope and the optical adapter based on a distortion parameter of the scope. Image distortion correction method. The fourth step includes a process of correcting distortion of the captured image based only on the optical data when the parameter reading in the second step or the third step fails in reading. The endoscopic image distortion correction method according to claim 7 .

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