Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T7/00—Image analysis
  • G06T7/50—Depth or shape recovery
  • G06T7/55—Depth or shape recovery from multiple images
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T7/00—Image analysis
  • G06T7/60—Analysis of geometric attributes
  • G06T7/62—Analysis of geometric attributes of area, perimeter, diameter or volume
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2200/00—Indexing scheme for image data processing or generation, in general
  • G06T2200/24—Indexing scheme for image data processing or generation, in general involving graphical user interfaces [GUIs]
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/10—Image acquisition modality
  • G06T2207/10004—Still image; Photographic image
  • G06T2207/10012—Stereo images
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/10—Image acquisition modality
  • G06T2207/10028—Range image; Depth image; 3D point clouds
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/20—Special algorithmic details
  • G06T2207/20092—Interactive image processing based on input by user
  • G06T2207/20101—Interactive definition of point of interest, landmark or seed

Definitions

• the subject matter disclosed herein relates to a method and device for displaying a two-dimensional image of a viewed object simultaneously with an image depicting a three- dimensional geometry of the viewed object using a video inspection device.
• Video inspection devices such as video endoscopes or borescopes, can be used to inspect a surface of an object to identify and analyze anomalies (e.g., pits or dents) on the object that may have resulted from, e.g., damage, wear, corrosion, or improper installation.
• anomalies e.g., pits or dents
• the surface of the object is inaccessible and cannot be viewed without the use of the video inspection device.
• a video inspection device can be used to inspect the surface of a blade of a turbine engine on an aircraft or power generation unit to identify any anomalies that may have formed on the surface to determine if any repair or further maintenance is required.
• a video inspection device can be used to obtain and display a two-dimensional image of the surface of a viewed object showing the anomaly to determine the dimensions of an anomaly on the surface.
• This two-dimensional image of the surface can be used to generate three-dimensional data of the surface that provides the three-dimensional coordinates (e.g., (x, y, z)) of a plurality of points on the surface, including proximate to an anomaly.
• the user can operate the video inspection device in a measurement mode to enter a measurement screen in which the user places cursors on the two-dimensional image to determine geometric dimensions of the anomaly.
• the contour of a viewed feature is difficult to assess from the two-dimensional image, making highly accurate placement of the cursors proximate to the anomaly difficult as it is difficult for the user to visualize the measurement being performed in three-dimensional space. This process may not always result in the desired geometric dimension or
• a method and device for displaying a two-dimensional image of a viewed object simultaneously with an image depicting a three-dimensional geometry of the viewed object using a video inspection device is disclosed.
• the video inspection device displays a two- dimensional image of the object surface of a viewed object, and determines the three- dimensional coordinates of a plurality of surface points.
• At least one rendered image of the three-dimensional geometry of the viewed object is displayed simultaneously with the two- dimensional image.
• the rendered image of the three-dimensional geometry of the viewed object is automatically updated.
• embodiments of the method and device for displaying a two-dimensional image of a viewed object simultaneously with an image depicting a three-dimensional geometry of the viewed object is that the accuracy of the measurement is improved since the user is provided with an additional and better perspective of the anomaly, and the time to perform the measurement of an anomaly is reduced.
• a method for inspecting an object surface of a viewed object is disclosed.
• the method includes the steps of displaying a two-dimensional image of the object surface on a display, determining the three-dimensional coordinates of a plurality of points on the object surface using a central processor unit, determining a rendered image of the three-dimensional geometry of at least a portion of the object surface using the central processor unit, simultaneously displaying the two-dimensional image and the rendered image on the display, placing a plurality of measurement cursors on the two-dimensional image using a pointing device and displaying the plurality of measurement cursors on the two- dimensional image on the display, displaying on the rendered image a plurality of measurement identifiers corresponding to the measurement cursors on the two-dimensional image, and determining a measurement dimension of the object surface based on the locations of the plurality of measurement cursors on the two-dimensional image using the central processor unit.
• the method includes the steps of placing a plurality of measurement cursors on the rendered image using a pointing device and displaying the plurality of measurement cursors on the rendered image on the display displaying on the two- dimensional image a plurality of measurement identifiers corresponding to the measurement cursors on the rendered image, and determining a measurement dimension of the object surface based on the locations of the plurality of measurement cursors on the rendered image using the central processor unit.
• the method includes the steps of displaying a two- dimensional stereo image of the object surface on a display, determining the three- dimensional coordinates of a plurality of points on the object surface using a central processor unit using stereo techniques, determining a rendered image of the three- dimensional geometry of at least a portion of the object surface using the central processor unit, and simultaneously displaying the two-dimensional stereo image and the rendered image on the display.
• a device for inspecting an object surface of a viewed object includes an elongated probe comprising an insertion tube, an imager located at a distal end of the insertion tube for obtaining a two-dimensional stereo image of the object surface, a central processor unit for determining the three-dimensional coordinates of a plurality of points on the object surface, and determining a rendered image of the three-dimensional geometry of at least a portion of the object surface, and a display for simultaneously displaying the two-dimensional stereo image and the rendered image.
• FIG. 1 is a block diagram of an exemplary video inspection device
• FIG. 2 is an exemplary image obtained by the video inspection device of the object surface of a viewed object having an anomaly in an exemplary embodiment
• FIG. 3 is a flow diagram of an exemplary method for automatically identifying the deepest point on the surface of an anomaly on a viewed object shown in the image of FIG. 2 in an exemplary embodiment
• FIG. 4 illustrates an exemplary reference surface determined by the video inspection device
• FIG. 5 illustrates an exemplary region of interest determined by the video inspection device
• FIG. 6 illustrates another exemplary region of interest determined by the video inspection device
• FIG. 7 is a graphical representation of an exemplary profile of the object surface of the viewed object shown in the image of FIG. 1 in an exemplary embodiment
• FIG. 8 is another image obtained by the video inspection device of the surface of a viewed object having an anomaly in an exemplary embodiment
• FIG. 9 is a flow diagram of a method for displaying three-dimensional data for inspection of the surface of the viewed object shown in the image of FIG. 8 in an exemplary embodiment
• FIG. 10 is a display of a subset of a plurality of surface points in a point cloud view
• FIG. 11 is a flow diagram of an exemplary method for displaying a two- dimensional image of viewed object simultaneously with an image depicting the three- dimensional geometry of the viewed object in another exemplary embodiment
• FIG. 12 is a display of a two-dimensional image and a stereo image of the viewed object
• FIG. 13 is a display of a two-dimensional image of the viewed object with measurement cursors and a rendered image of the three-dimensional geometry of the viewed object in the form of a depth profile image with measurement identifiers; and [0027] FIG. 14 is a display of a two-dimensional image of the viewed object with measurement cursors and a rendered image of the three-dimensional geometry of the viewed object in the form of a point cloud view with measurement identifiers.
• FIG. 1 is a block diagram of an exemplary video inspection device 100. It will be understood that the video inspection device 100 shown in FIG. 1 is exemplary and that the scope of the invention is not limited to any particular video inspection device 100 or any particular configuration of components within a video inspection device 100.
• Video inspection device 100 can include an elongated probe 102 comprising an insertion tube 110 and a head assembly 120 disposed at the distal end of the insertion tube 110.
• Insertion tube 110 can be a flexible, tubular section through which all interconnects between the head assembly 120 and probe electronics 140 are passed.
• Head assembly 120 can include probe optics 122 for guiding and focusing light from the viewed object 202 onto an imager 124.
• the probe optics 122 can comprise, e.g., a lens singlet or a lens having multiple components.
• the imager 124 can be a solid state CCD or CMOS image sensor for obtaining an image of the viewed object 202.
• a detachable tip or adaptor 130 can be placed on the distal end of the head assembly 120.
• the detachable tip 130 can include tip viewing optics 132 (e.g., lenses, windows, or apertures) that work in conjunction with the probe optics 122 to guide and focus light from the viewed object 202 onto an imager 124.
• the detachable tip 130 can also include illumination LEDs (not shown) if the source of light for the video inspection device 100 emanates from the tip 130 or a light passing element (not shown) for passing light from the probe 102 to the viewed object 202.
• the tip 130 can also provide the ability for side viewing by including a waveguide (e.g., a prism) to turn the camera view and light output to the side.
• the tip 130 may also provide stereoscopic optics or structured-light projecting elements for use in determining three-dimensional data of the viewed surface. The elements that can be included in the tip 130 can also be included in the probe 102 itself.
• the imager 124 can include a plurality of pixels formed in a plurality of rows and columns and can generate image signals in the form of analog voltages representative of light incident on each pixel of the imager 124.
• the image signals can be propagated through imager hybrid 126, which provides electronics for signal buffering and conditioning, to an imager harness 112, which provides wires for control and video signals between the imager hybrid 126 and the imager interface electronics 142.
• the imager interface electronics 142 can include power supplies, a timing generator for generating imager clock signals, an analog front end for digitizing the imager video output signal, and a digital signal processor for processing the digitized imager video data into a more useful video format.
• the imager interface electronics 142 are part of the probe electronics 140, which provide a collection of functions for operating the video inspection device 10.
• the probe electronics 140 can also include a calibration memory 144, which stores the calibration data for the probe 102 and/or tip 130.
• a microcontroller 146 can also be included in the probe electronics 140 for communicating with the imager interface electronics 142 to determine and set gain and exposure settings, storing and reading calibration data from the calibration memory 144, controlling the light delivered to the viewed object 202, and communicating with a central processor unit (CPU) 150 of the video inspection device 100.
• CPU central processor unit
• the imager interface electronics 142 can also communicate with one or more video processors 160.
• the video processor 160 can receive a video signal from the imager interface electronics 142 and output signals to various monitors 170, 172, including an integral display 170 or an external monitor 172.
• the integral display 170 can be an LCD screen built into the video inspection device 100 for displaying various images or data (e.g., the image of the viewed object 202, menus, cursors, measurement results) to an inspector.
• the external monitor 172 can be a video monitor or computer-type monitor connected to the video inspection device 100 for displaying various images or data.
• the video processor 160 can provide/receive commands, status information, streaming video, still video images, and graphical overlays to/from the CPU 150 and may be comprised of FPGAs, DSPs, or other processing elements which provide functions such as image capture, image enhancement, graphical overlay merging, distortion correction, frame averaging, scaling, digital zooming, overlaying, merging, flipping, motion detection, and video format conversion and compression.
• the CPU 150 can be used to manage the user interface by receiving input via a joystick 180, buttons 182, keypad 184, and/or microphone 186, in addition to providing a host of other functions, including image, video, and audio storage and recall functions, system control, and measurement processing.
• the joystick 180 can be manipulated by the user to perform such operations as menu selection, cursor movement, slider adjustment, and articulation control of the probe 102, and may include a push-button function.
• the buttons 182 and/or keypad 184 also can be used for menu selection and providing user commands to the CPU 150 (e.g., freezing or saving a still image).
• the microphone 186 can be used by the inspector to provide voice instructions to freeze or save a still image.
• the video processor 160 can also communicate with video memory 162, which is used by the video processor 160 for frame buffering and temporary holding of data during processing.
• the CPU 150 can also communicate with CPU program memory 152 for storage of programs executed by the CPU 150.
• the CPU 150 can be in communication with volatile memory 154 (e.g., RAM), and non-volatile memory 156 (e.g., flash memory device, a hard drive, a DVD, or an EPROM memory device).
• volatile memory 154 e.g., RAM
• non-volatile memory 156 e.g., flash memory device, a hard drive, a DVD, or an EPROM memory device.
• the non-volatile memory 156 is the primary storage for streaming video and still images.
• the CPU 150 can also be in communication with a computer I/O interface 158, which provides various interfaces to peripheral devices and networks, such as USB, Firewire, Ethernet, audio I/O, and wireless transceivers.
• This computer I/O interface 158 can be used to save, recall, transmit, and/or receive still images, streaming video, or audio.
• a USB "thumb drive” or CompactFlash memory card can be plugged into computer I/O interface 158.
• the video inspection device 100 can be configured to send frames of image data or streaming video data to an external computer or server.
• the video inspection device 100 can incorporate a TCP/IP communication protocol suite and can be incorporated in a wide area network including a plurality of local and remote computers, each of the computers also incorporating a TCP/IP communication protocol suite. With incorporation of TCP/IP protocol suite, the video inspection device 100 incorporates several transport layer protocols including TCP and UDP and several different layer protocols including HTTP and FTP. [0038] It will be understood that, while certain components have been shown as a single component (e.g., CPU 150) in FIG. 1, multiple separate components can be used to perform the functions of the CPU 150.
• FIG. 2 is an exemplary image 200 obtained by the video inspection device 100 of the object surface 210 of a viewed object 202 having an anomaly 204 in an exemplary embodiment of the invention.
• the anomaly 204 is shown as a dent, where material has been removed from the object surface 210 of the viewed object 202 in the anomaly 204 by damage or wear.
• the anomaly 204 shown in this exemplary embodiment is just an example and that the inventive method applies to other types of irregularities (e.g., cracks, corrosion pitting, coating loss, surface deposits, etc.).
• the image 200 can be used to determine the dimensions of the anomaly 204 (e.g., height or depth, length, width, area, volume, point to line, profile slice, etc.).
• the image 200 used can be a two-dimensional image 200 of the object surface 210 of the viewed object 202, including the anomaly 204.
• FIG. 3 is a flow diagram of an exemplary method 300 for automatically identifying the deepest point on the object surface 210 of an anomaly 204 on a viewed object 202 shown in the image 200 of FIG. 2 in an exemplary embodiment of the invention. It will be understood that the steps described in the flow diagram of FIG. 3 can be performed in a different order than shown in the flow diagram and that not all of the steps are required for certain embodiments.
• the user can use the video inspection device 100 (e.g., the imager 124) to obtain at least one image 200 of the object surface 210 of a viewed object 202 having an anomaly 204 and display it on a video monitor (e.g., an integral display 170 or external monitor 172).
• a video monitor e.g., an integral display 170 or external monitor 172.
• the image 200 can be displayed in a measurement mode of the video inspection device.
• the video inspection device 100 can determine the three-dimensional coordinates (e.g., (x, y, z)) of a plurality of surface points on the object surface 210 of the viewed object 202, including surface points of the anomaly 204.
• the video inspection device can generate three-dimensional data from the image 200 in order to determine the three- dimensional coordinates.
• Several different existing techniques can be used to provide the three-dimensional coordinates of the surface points in the image 200 (FIG. 2) of the object surface 210 (e.g., stereo, scanning systems, stereo triangulation, structured light methods such as phase shift analysis, phase shift moire, laser dot projection, etc.).
• the three-dimensional coordinates may be determined using one or more images captured in close time proximity that may include projected patterns and the like. It is to be understood that references to three-dimensional coordinates determined using image 200 may also comprise three-dimensional coordinates determined using one or a plurality of images 200 of the object surface 210 captured in close time proximity, and that the image 200 displayed to the user during the described operations may or may not actually be used in the determination of the three-dimensional coordinates.
• the video inspection device 100 can determine a reference surface 250.
• the reference surface 250 can be flat, while in other embodiments the reference surface 250 can be curved.
• the reference surface 250 can be in the form of a plane, while in other embodiments, the reference surface 250 can be in the form of a different shape (e.g., cylinder, sphere, etc.).
• a user can use the joystick 180 (or other pointing device (e.g., mouse, touch screen)) of the video inspection device 100 to select one or more reference surface points on the obj ect surface 210 of the viewed object 202 proximate to the anomaly 204 to determine a reference surface.
• the joystick 180 or other pointing device (e.g., mouse, touch screen) of the video inspection device 100 to select one or more reference surface points on the obj ect surface 210 of the viewed object 202 proximate to the anomaly 204 to determine a reference surface.
• a total of three reference surface points 221, 222, 223 are selected on the object surface 210 of the viewed object 202 proximate to the anomaly 204 to conduct a depth measurement of the anomaly 204, with the three reference surface points 221, 222, 223 selected on the object surface 210 proximate to the anomaly 204.
• the plurality of reference surface points 221 , 222, 223 on the object surface 210 of the viewed object 202 can be selected by placing reference surface cursors 231, 232, 233 (or other pointing devices) on pixels 241, 242, 243 of the image 200 corresponding to the plurality of reference surface points 221 , 222, 223 on the object surface 210.
• the video inspection device 100 e.g., the CPU 150
• the CPU 150 can determine the three-dimensional coordinates of each of the plurality of reference surface points 221, 222, 223.
• the three-dimensional coordinates of three or more surface points proximate to one or more of the three reference surface points 221, 222, 223 selected on the object surface 210 proximate to the anomaly 204 can be used to determine a reference surface 250 (e.g., a plane).
• the video inspection device 100 can perform a curve fitting of the three-dimensional coordinates of the three reference surface points 221 , 222, 223 to determine an equation for the reference surface 250 (e.g., for a plane) having the following form: k + k -V 0 ) where (XIRS, yiRS, ZIRS) are coordinates of any three-dimensional point on the defined reference surface 250 and koRS, kiRs, and k2RS are coefficients obtained by a curve fitting of the three-dimensional coordinates.
• a plurality of reference surface points are used to perform the curve fitting.
• the curve fitting finds the k coefficients that give the best fit to the points used (e.g., least squares approach).
• the k coefficients then define the plane or other reference surface 250 that approximates the three-dimensional points used.
• the z results will generally not exactly match the z coordinates of the points due to noise and any deviation from a plane that may actually exist.
• the XIRSI and yiRsi can be any arbitrary values, and the resulting ZIRS tells you the z of the defined plane at XIRS, yiRS. Accordingly, coordinates shown in these equations can be for arbitrary points exactly on the defined surface, not necessarily the points used in the fitting to determine the k coefficients.
• the video inspection device 100 e.g., the CPU 150
• the video inspection device 100 can identify a plurality of pixels proximate to each of the pixels of the image corresponding to a plurality of points on the object surface 210 proximate to the reference surface point(s), and determine the three- dimensional coordinates of the proximate point(s), enabling curve fitting to determine a reference surface 250.
• the reference surface 250 can be formed by using a pointing device to place a reference surface shape 260 (e.g., circle, square, rectangle, triangle, etc.) proximate to anomaly 204 and using the reference surface points 261, 262, 263, 264 of the shape 260 to determine the reference surface 250.
• a reference surface shape 260 e.g., circle, square, rectangle, triangle, etc.
• the reference surface points 261 , 262, 263, 264 of the shape 260 can be points selected by the pointing device or be other points on or proximate to the perimeter of the shape that can be sized to enclose the anomaly 204.
• the video inspection device 100 determines a region of interest 270 proximate to the anomaly 204 based on the reference surface points of the reference surface 250.
• the region of interest 270 includes a plurality of surface points of the anomaly 204.
• a region of interest 270 is formed by forming a region of interest shape 271 (e.g., a circle) based on two or more of the reference surface points 221, 222, 223.
• the region of interest 270 can be determined by forming a cylinder
• a region of interest could be formed within the reference surface shape 260 and reference surface points 261 , 262, 263, 264.
• the exemplary region of interest shape 271 in FIG. 5 is formed by passing through the reference surface points 221, 222, 223, in another embodiment, a smaller diameter reference surface shape can be formed by passing only proximate to the reference surface points. For example, as shown in FIG.
• a region of interest 280 is formed by passing a region of interest shape 281 (e.g., a circle) proximate to two of the reference surface points 221, 222, where the diameter of the circle 281 is smaller than the distance between the two reference surface points 221, 222. It will be understood that region of interest shapes 271, 281 and the regions of interest 270, 280 may or may not be displayed on the image 200.
• a region of interest shape 281 e.g., a circle
• the video inspection device 100 determines the distance (i.e., depth) from each of the plurality of surface points in the region of interest to the reference surface 250.
• the video inspection device 100 determines the distance of a line extending between the reference surface 250 and each of the plurality of surface points in the region of interest 270, 280, wherein the line perpendicularly intersects the reference surface 250.
• the video inspection device determines the location of the deepest surface point 224 in the region of interest 270, 280 by determining the surface point that is furthest from the reference surface 250 (e.g., selecting the surface point with the longest line extending to the reference surface 250).
• the "deepest point” or “deepest surface point” can be a furthest point that is recessed relative to the reference surface 250 or a furthest point (i.e., highest point) that is protruding from the references surface 250.
• the video inspection device 100 can identify the deepest surface point 224 in the region of interest 270, 280 on the image by displaying, e.g., a cursor 234 (FIG. 5) or other graphic identifier 282 (FIG. 6) on the deepest surface point 224.
• the video inspection device 100 can display the depth 290 (in inches or millimeters) of the deepest surface point 224 in the region of interest 270, 280 on the image 200 (i.e., the length of the perpendicular line extending from the deepest surface point 224 to the reference surface 250.
• the cursor 234 or other graphic identifier 282 FIG. 5
• the video inspection device 100 reduces the time required to perform the depth measurement and improves the accuracy of the depth measurement since the user does not need to manually identify the deepest surface point 224 in the anomaly 204.
• the user can also move the cursor 234 within the region of interest 270, 280 to determine the depth of other surface points in the region of interest 270, 280.
• the video inspection device 100 e.g., CPU 150
• the video inspection device 100 can monitor the movement of the cursor 234 and detect when the cursor 234 has stopped moving. When the cursor 234 stops moving for a predetermined amount of time (e.g., 1 second), the video inspection device 100 (e.g., the CPU 150) can determine the deepest surface point proximate to the cursor 234 (e.g., a predetermined circle centered around the cursor 234) and automatically move the cursor 234 to that position.
• FIG. 7 is a graphical representation of an exemplary profile 370 of the object surface 210 of the viewed object 202 shown in the image 200 of FIG. 1.
• the reference surface 250 is shown extending between two reference surface points 221, 222 and their respective reference surface cursors 231, 232.
• the location and depth 290 of the deepest surface point 224 in the region of interest is also shown in the graphical representation.
• a point cloud view can also be used to show the deepest surface point 224.
• FIG. 8 is another image 500 obtained by the video inspection device 100 of the object surface 510 of a viewed object 502 having an anomaly 504 in an exemplary embodiment of the invention.
• the anomaly 504 is shown as a dent, where material has been removed from the object surface 510 of the viewed object 502 in the anomaly 504 by damage or wear. It will be understood that the anomaly 504 shown in this exemplary embodiment is just an example and that the inventive method applies to other types of irregularities (e.g., cracks, corrosion pitting, coating loss, surface deposits, etc.).
• the image 500 can be used to determine the dimensions of the anomaly 504 (e.g., height or depth, length, width, area, volume, point to line, profile slice, etc.).
• the image 500 used can be a two-dimensional image 500 of the object surface 510 of the viewed object 502, including the anomaly 504.
• FIG. 9 is a flow diagram of a method 600 for displaying three-dimensional data for inspection of the object surface 510 of the viewed object 502 shown in the image 500 of FIG. 8 in an exemplary embodiment of the invention. It will be understood that the steps described in the flow diagram of FIG. 9 can be performed in a different order than shown in the flow diagram and that not all of the steps are required for certain embodiments.
• the operator can use the video inspection device 100 to obtain an image 500 of the object surface 510 of a viewed object 502 having an anomaly 504 and display it on a video monitor (e.g., an integral display 170 or external monitor 172).
• a video monitor e.g., an integral display 170 or external monitor 172
• the image 500 can be displayed in a measurement mode of the video inspection device.
• the CPU 150 of the video inspection device 100 can determine the three-dimensional coordinates (xisi, yisi, sii) in a first coordinate system of a plurality of surface points on the object surface 510 of the viewed object 502, including the anomaly 504.
• the video inspection device can generate three-dimensional data from the image 500 in order to determine the three-dimensional coordinates.
• several different existing techniques can be used to provide the three-dimensional coordinates of the points on the image 500 of the object surface 510 (e.g., stereo, scanning systems, structured light methods such as phase shifting, phase shift moire, laser dot projection, etc.).
• an operator can use the joystick 180 (or other pointing device (e.g., mouse, touch screen)) of the video inspection device 100 to select a plurality of measurement points on the object surface 510 of the viewed object 502 proximate the anomaly 504 to conduct a particular type of measurement.
• the number of measurement points selected is dependent upon the type measurement to be conducted. Certain measurements can require selection of two measurement points (e.g., length, profile), while other measurements can require selection of three or more measurement points (e.g., point-to- line, area, multi-segment).
• two measurement points e.g., length, profile
• other measurements can require selection of three or more measurement points (e.g., point-to- line, area, multi-segment).
• a total of four measurement points 521, 522, 523, 524 are selected on the object surface 510 of the viewed object 502 proximate the anomaly 504 to conduct a depth measurement of the anomaly 504, with three of the measurement points 521, 522, 523 selected on the object surface 510 proximate the anomaly 504, and the fourth measurement point 524 selected to be at the deepest point of the anomaly 504.
• the plurality of measurement points 521 , 522, 523, 524 on the object surface 510 of the viewed object 502 can be selected by placing cursors 531 , 532, 533, 534 (or other pointing devices) on pixels 541, 542, 543, 544 of the image 500 corresponding to the plurality of measurement points 521 , 522, 523, 524 on the object surface 510.
• the video inspection device 100 can determine the three-dimensional coordinates in the first coordinate system of each of the plurality of measurement points 521 , 522, 523, 524. It will be understood that the inventive method is not limited to depth measurements or measurements involving four selected measurement points, but instead applies to various types of measurements involving different numbers of points, including those discussed above.
• the CPU 150 of the video inspection device 100 can determine a reference surface 550.
• the three-dimensional coordinates of three or more surface points proximate one or more of the three measurement points 521, 522, 523 selected on the object surface 510 proximate the anomaly 504 can be used to determine a reference surface 550 (e.g., a plane).
• the video inspection device 100 can perform a curve fitting of the three-dimensional coordinates in the first coordinate system of the three measurement points 521 , 522, 523 (XMI, yiMi, ziMi) to determine an equation for the reference surface 550 (e.g., for a plane) having the following form:
• (XIRSI, yiRSi, ZIRSI) are coordinates of any three-dimensional point in the first coordinate system on the defined reference surface 550 and koRsi, kiRsi, and k2Rsi are coefficients obtained by a curve fitting of the three-dimensional coordinates in the first coordinate system.
• a plurality of measurement points i.e., at least as many points as the number of k coefficients
• the curve fitting finds the k coefficients that give the best fit to the points used (e.g., least squares approach).
• the k coefficients then define the plane or other reference surface 550 that approximates the three-dimensional points used.
• the z results will generally not exactly match the z coordinates of the points due to noise and any deviation from a plane that may actually exist.
• the XIRSI and yiRsi can be any arbitrary values, and the resulting ZIRSI tells you the z of the defined plane at XIRSI, yiRSi. Accordingly, coordinates shown in these equations can be for arbitrary points exactly on the defined surface, not necessarily the points used in the fitting to determine the k coefficients.
• the video inspection device 100 can identify a plurality of pixels proximate each of the pixels of the image corresponding to a plurality of points on the object surface 510 proximate each of the measurement points, and determine the three-dimensional coordinates of those points, enabling curve fitting to determine a reference surface 550.
• the video inspection device 100 can determine the three-dimensional coordinates in the first coordinate system of a plurality of frame points 560 (xiFi, yiFi, ziFi) forming a frame 562 (e.g., a rectangle) on the reference surface 550 around the anomaly 504 and the measurement points 521 , 522, 523, 524, which can be used later to display the location of the reference surface 550.
• a frame 562 e.g., a rectangle
• the video inspection device 100 can conduct a measurement (e.g., depth) of the anomaly 504 by determining the distance between the fourth measurement point 524 selected to be at the deepest point of the anomaly 504 and the reference surface 550.
• the accuracy of this depth measurement is determined by the accuracy in selecting the plurality of measurement points 521 , 522, 523, 524 on the object surface 510 of the viewed obj ect 502.
• the contour of the anomaly 504 in the image 500 is difficult to assess from the two-dimensional image and may be too small or otherwise insufficient to reliably locate the plurality of measurement points 521, 522, 523, 524.
• an operator will want further detail in the area of the anomaly 504 to evaluate the accuracy of the location of these measurement points 521, 522, 523, 524. So while some video inspection devices 100 can provide a point cloud view of the full image 500, that view may not provide the required level of detail of the anomaly 504 as discussed previously.
• the inventive method creates a subset of the three-dimensional data in the region of interest.
• the CPU 150 of the video inspection device 100 can establish a second coordinate system different from the first coordinate system.
• the second coordinate system can be based on the reference surface 550 and the plurality of measurement points 521, 522, 523, and 524.
• the three-dimensional coordinates of the points on the reference surface 550 corresponding to the measurement points 521, 522, 523 can be the same.
• the measurement points 521, 522, 523 do not fall exactly on the reference surface 550, and therefore have different coordinates.
• the line Given a point on a line (xl, y 1 , zl) and the line's directions (dx, dy, dz), the line can be defined by:
• Parallel lines have the same or linearly scaled line directions.
• a line that is perpendicular to the reference surface 550 and passing through a surface point (xs, ys, zs) can be defined as:
• the coordinates of a point on the reference surface 550 (XIRSI, yiRSi, ziRsi) corresponding to a point on the object surface 510 (xisi, yisi, sii) (e.g. three- dimensional coordinates in a first coordinate system of points on the reference surface 550 corresponding to the measurement points 521 , 522, 523, 524), can be determined by defining a line normal to the reference surface 550 having directions given in equations (8)-(10) and passing through (xisi, yisi, sii), and determining the coordinates of the intersection of that line with the reference surface 550.
• equations (2) and (11) From equations (2) and (11):
• Locating the origin of the second coordinate system proximate the average position 525 in the area of the anomaly 504 with the z values being the perpendicular distance from each surface point to the reference surface 550 allows a point cloud view rotation to be about the center of the area of the anomaly 504 and permits any depth map color scale to indicate the height or depth of a surface point from the reference surface 550.
• the CPU 150 of the video inspection device 100 transforms the three-dimensional coordinates in the first coordinate system (xii, y ii, z ii) determined for various points (e.g., the plurality of surface points, the plurality of measurement points 521, 522, 523, 524, the points on the reference surface 550 including the frame points 560, etc.) to three-dimensional coordinates in the second coordinate system (xi2, y a, z 12).
• various points e.g., the plurality of surface points, the plurality of measurement points 521, 522, 523, 524, the points on the reference surface 550 including the frame points 560, etc.
• the three-dimensional coordinates in the second coordinate system can be determined by the following:
• Xi2 (Xil - XMlavg) * Too + (yil - yMlavg) * TlO + (zil - ZMlavg) * T20
• yi2 (Xil - XMlavg) * Toi + (yil - yMlavg) * Til + (Zil - ZMlavg) * T21
• Zi2 (Xil - XMlavg) * ⁇ 2 + (yil - yMlavg) * Tl2 + (zil - ZMlavg) * T22 (18) where the transformation matrix values are the line direction values of the new x, y, and z axes in the first coordinate system.
• the CPU 150 of the video inspection device 100 determines a subset of the plurality of surface points that are within a region of interest on the object surface 510 of the viewed obj ect 502.
• the region of interest can be a limited area on the obj ect surface 510 of the viewed object 502 surrounding the plurality of selected measurement points 521 , 522, 523, 524 to minimize the amount of three-dimensional data to be used in a point cloud view. It will be understood that the step of determining of the subset 660 can take place before or after the transformation step 660.
• the video inspection device 100 may transform the coordinates for all surface points, including points that are outside the region of interest, before determining which of those points are in the region of interest.
• the video inspection device 100 may only need to transform the coordinates for those surface points that are within the region of interest.
• the distance (d) from that position to a point on the reference surface 550 corresponding to a surface point (xiRS2, yiRS2, ziRS2) is given by:
• the video inspection device 100 can write the three-dimensional coordinates of that surface point and the pixel color corresponding to the depth of that surface point to a point cloud view file.
• the region of interest is in the form of a cylinder that includes surface points falling within the radius of the cylinder. It will be understood that other shapes and methods for determining the region of interest can be used.
• the region of interest can also be defined based upon the depth of the anomaly 504 on the object surface 510 of the viewed object 502 determined by the video inspection device 100 in the first coordinate system. For example, if the depth of the anomaly 504 was measured to be 0.005 inches (0.127 mm), the region of interest can be defined to include only those points having distances from the reference surface 550 (or z dimensions) within a certain range ( ⁇ 0.015 inches (0.381 mm)) based on the distance of one or more of the measurement points 521 , 522, 523, 524 to the reference surface 550.
• the video inspection device 100 can write the three- dimensional coordinates of that surface point and the pixel color corresponding to the depth of that surface point to a point cloud view file. If a surface point has a depth value outside of the region of interest, the video inspection device 100 may not include that surface point in a point cloud view file.
• the monitor 170, 172 of the video inspection device 100 can display a rendered three-dimensional view (e.g., a point cloud view) 700 of the subset of the plurality of surface points in the three-dimensional coordinates of the second coordinate system, having an origin 725 at the center of the view.
• the display of the point cloud view 700 can include a color map to indicate the distance between each of the surface points and the reference surface 750 in the second coordinate system (e.g., a first point at a certain depth is shown in a shade of red corresponding that depth, a second point at a different depth is shown in a shade of green corresponding to that depth).
• the displayed point cloud view 700 can also include the location of the plurality of measurement points 721, 722, 723, 724. To assist the operator in viewing the point cloud view 700, the video inspection device 100 can also determine three- dimensional line points 771 , 772, 773 along straight lines between two or more of the plurality of measurement points 721 , 722, 723 in the three-dimensional coordinates of the second coordinate system, and display those line points 771 , 772, 773 in the point cloud view 700.
• the point cloud view 700 can also include a depth line 774 from the measurement point 724 intended to be located at the deepest point of the anomaly 504 to the reference surface 750. In one embodiment, the video inspection device 100 can determine if the depth line 774 exceeds a tolerance specification or other threshold and provide a visual or audible indication or alarm of such an occurrence.
• the displayed point cloud view 700 can also include a plurality of frame points 760 forming a frame 762 on the reference surface 750 in the second coordinate system to indicate the location of the reference surface 750.
• the displayed point cloud view 700 can also include a scale indicating the perpendicular distance from the reference surface 750.
• the operator can more easily analyze the anomaly 504 and determine if the depth measurement and placement of the measurement points 721, 722, 723, 724 was accurate.
• the operator can alter the location of one or more of the measurement points 721, 722, 723, 724 in the point cloud view 700 if correction is required. Altematively, if correction is required, the operator can return to the two-dimensional image 500 of FIG. 8 and reselect one or more of the measurement points 521, 522, 523, 524, and repeat the process.
• the monitor 170, 172 of the video inspection device 100 can display a rendered three-dimensional view 700 of the subset of the plurality of surface points in the three-dimensional coordinates of the first coordinate system without ever conducting a transformation of coordinates.
• the point cloud view 700 based on the original coordinates can also include the various features described above to assist the operator, including displaying a color map, the location of the plurality of measurement points, three-dimensional line points, depth lines, frames, or scales.
• FIG. 11 is a flow diagram of an exemplary method 800 for displaying a two- dimensional image of viewed object simultaneously with an image depicting the three- dimensional geometry of the viewed object in another exemplary embodiment. It will be understood that the steps described in the flow diagram of FIG. 11 can be performed in a different order than shown in the flow diagram and that not all of the steps are required for certain embodiments.
• the video inspection device 100 obtains at least one two- dimensional image 903 of the object surface 911 of a viewed object 910 having an anomaly 912 and displays it on a first side 901 of the display 900 (e.g., an integral display 170, external monitor 172, or touch screen of a user interface). In one embodiment, the two-dimensional image 903 is displayed in a measurement mode of the video inspection device 100.
• the video inspection device 100 e.g., the CPU 150 of FIG.
• FIG. 12 is a display 900 of a two-dimensional first stereo image
• the video inspection device 100 e.g., the CPU 150
• the reference herein to a two-dimensional image with respect to stereo image 903, 904 can include both or either of the first (left) stereo image 903 and the second (right) stereo image 904.
• the three-dimensional coordinates of the surface points 913, 914 in the two-dimensional image 903 (FIG. 12) of the object surface 911 e.g., stereo, scanning systems, stereo triangulation, structured light methods such as phase shift analysis, phase shift moire, laser dot projection, etc.
• Most such techniques comprise the use of calibration data, which, among other things, includes optical characteristic data that is used to reduce errors in the three-dimensional coordinates that would otherwise be induced by optical distortions.
• the three- dimensional coordinates may be determined using one or more two-dimensional images captured in close time proximity that may include projected patterns and the like.
• references to three-dimensional coordinates determined using two- dimensional image 903 may also comprise three-dimensional coordinates determined using one or a plurality of two-dimensional images of the object surface 91 1 captured in close time proximity, and that the two-dimensional image 903 displayed to the operator during the described operations may or may not actually be used in the determination of the three- dimensional coordinates.
• step 830 of the exemplary method 800 (FIG. 11), and as shown in FIGS. 13 and 14, at least a portion of the two-dimensional image 903 of the viewed object 910 with measurement cursors 931, 932 is displayed on a first side 901 of the display 900 and a rendered image 905 of the three-dimensional geometry of at least a portion of the object surface 911 of the viewed object 910 is displayed on the second side 902 of the display 900.
• the rendered image 905 replaces the second (right) stereo image 904 in the display 900.
• the video inspection device 100 begins (and, in one embodiment, completes) the process of determining the three-dimensional coordinates (e.g., (x, y, z)) of the plurality of surface points 913, 914 on the object surface 911 of the viewed object 910 before the placement and display of the measurement cursors
• FIGS. 13 and 14 show a single rendered image 905 of the three-dimensional geometry of the object surface 911 of the viewed object 910 displayed on the second side 902 of the display 900, it will be understood that more than one rendered image 905 can be shown simultaneously with or without the two-dimensional image 903.
• the rendered image 905 is a depth profile image 906 showing the three-dimensional geometry of the object surface 911 of the viewed object 910, including the anomaly 912.
• the rendered image 905 is a point cloud view 907 showing the three-dimensional geometry of the object surface 911 of the viewed object 910, including the anomaly 912.
• the exemplary point cloud view 907 shown in FIG. 14 only a subset of the three-dimensional coordinates of the surface points 913, 914 on the object surface 911 of the viewed object 910 are displayed in a region of interest based on the location of the measurement cursors 931,
• the point cloud view 907 displays all of the computed three- dimensional coordinates of the surface points 913, 914 on the object surface 911 of the viewed object 910. In one embodiment, e.g., when the display is a user-interface touch screen, the user can rotate the point cloud view 907 using the touch screen.
• the point cloud view 907 may be colorized to indicate the distance between the surface points of the object surface 911 of the viewed object 910 and a reference surface 960 (e.g., reference plane determined using three- dimensional coordinates proximate to one or more of the plurality of measurement cursors 931, 932). For example, a first point at a certain depth is shown in a shade of red
• a color depth scale 908 is provided to show the relationship between the colors shown on the point cloud view 907 and their respective distances from the reference surface 960.
• the point could view 907 may be surfaced to graphically smooth the transition between adjacent points in the point cloud view 907.
• the video inspection device 100 saves as an image the split view of the two-dimensional image 903 and the rendered image 905.
• the video inspection device 100 can also save as metadata the original, full stereo image of the first (left) stereo image 903 and the second (right) stereo image 904 (e.g., grayscale only) as shown in FIG. 11 and the calibration data to allow re-computation of the three-dimensional data and re- measurement from the saved file.
• the video inspection device 100 can save the computed three-dimensional coordinates and/or disparity data as metadata, which reduces the processing time upon recall but results in a larger file size.
• measurement cursors 931, 932 are placed (using a pointing device) and displayed on the two-dimensional image 903 to allow the video inspection device 100 (e.g., the CPU 150) to determine the dimensions of the anomaly 912 (e.g., height or depth, length, width, area, volume, point to line, profile slice, etc.).
• the video inspection device 100 e.g., the CPU 150
• the dimensions of the anomaly 912 e.g., height or depth, length, width, area, volume, point to line, profile slice, etc.
• the two-dimensional image is not a stereo image
• measurement cursors 931, 932 as shown in FIGS.
• the video inspection device 100 e.g., the CPU 150
• the dimensions of the anomaly 912 e.g., height or depth, length, width, area, volume, point to line, profile slice, etc.
• measurement cursors can be placed (using a pointing device) on the rendered image 905 of the three- dimensional geometry of at least a portion of the object surface 911 of the viewed object 910 on the second side 902 of the display 900.
• the first measurement cursor 931 is placed on the first measurement point 921 on the object surface 911 of the viewed object 910 and the second measurement cursor 932 is placed on the second measurement point 922 on the object surface 911 of the viewed object 910. Since the three-dimensional coordinates of the measurement points 921, 922 on the object surface 911 of the viewed object 910 are known, a geometric measurement (e.g., depth or length measurement) of the object surface 911 can be performed by the user and the video inspection device 100 (e.g., the CPU 150) can determine the measurement dimension 950 as shown in FIGS. 13 and 14. In the example shown in FIGS. 13 and 14, a measurement line 933 is displayed on the two-dimensional image 903.
• a geometric measurement e.g., depth or length measurement
• the rendered image 905 of the three-dimensional geometry of the object surface 911 of the viewed object 910 is displayed on the second side 902 of the display 900 in order to assist in the placement of the measurement cursors 931, 932 on the two-dimensional image 903 to conduct the geometric measurement.
• these measurement cursors 931, 932 are placed based solely on the view provided by the two-dimensional image 903, which may not allow for accurate placement of the measurement cursors 931, 932 and accurate measurements.
• measurement identifiers 941, 942 corresponding to the measurement cursors 931, 932 placed on the two-dimensional image 903 are displayed on the rendered image 905 of the three-dimensional geometry of the object surface 911 of the viewed object 912.
• the first measurement identifier 941 is shown on the rendered image 905 at the same three- dimensional coordinate of the object surface 911 of the viewed object 912 as the first measurement cursor 931
• the second measurement identifier 942 is shown on the rendered image 905 at the same three-dimensional coordinate of the object surface 911 of the viewed object 912 as the second measurement cursor 932.
• a measurement line identifier 943 corresponding to the measurement line 933 (e.g., depth measurement line) in the two-dimensional image 901 is displayed.
• This rendered image 905 of the three-dimensional geometry of the object surface 911 of the viewed object 910 simultaneously displayed with the two-dimensional image 903 of the object surface 911 of the viewed object 912 allows the user to more accurately place the measurement cursors 931, 932 to provide a more accurate geometric measurement.
• the measurement cursors are placed (using a pointing device) on the rendered image 905, measurement identifiers corresponding to the measurement cursors are displayed on the two-dimensional image 903.
• the video inspection device 100 e.g., the CPU 150 automatically updates the location of the measurement identifiers 941, 942
• the corresponding to the measurement cursors 931, 932 and the rendered image 905 (e.g., region of interest or depth colors of the point cloud view 907 in FIG. 14) of the three-dimensional geometry of the object surface 911 of the viewed object 912 also changes to allow the user to visualize the new measurement virtually in real time.
• the measurement cursors 931, 932 are placed in the two-dimensional image 903, the
• measurement identifiers 941, 942 can be repositioned in the rendered image 905.
• the video inspection device 100 e.g., the CPU 150
• the measurement identifiers can be repositioned in the two-dimensional image 903.
• the video inspection device 100 determines the measurement dimension 950 sought by the user for the particular geometric measurement (e.g., depth or length measurement) based on the locations of the measurement cursors 931 , 932 and displays that measurement dimension 950 on the display 900.
• the measurement dimension can displayed on the display 900 on the rendered image 905.
• soft keys 909 can be provided on the display 900 to provide various functions to the user in obtaining images and taking measurements (e.g., views, undo, add measurement, next measurement, options, delete, annotation, take image, reset, zoom, full image/measurement image, depth map on/off, etc.).
• measurements e.g., views, undo, add measurement, next measurement, options, delete, annotation, take image, reset, zoom, full image/measurement image, depth map on/off, etc.
• the particular soft keys 909 displayed can change based on the active image.
• embodiments of the invention automatically determine the depth or height of a point on an anomaly on a surface.
• a technical effect is to reduce the time required to perform the measurement and to improve the accuracy of the measurement.
• aspects of the present invention may be embodied as a system, method, or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.), or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "service,” “circuit,” “circuitry,” “module,” and/or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
• the computer readable medium may be a computer readable signal medium or a computer readable storage medium.
• a computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.
• a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
• Program code and/or executable instructions embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
• Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages.
• the program code may execute entirely on the user's computer (device), partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server.
• the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
• LAN local area network
• WAN wide area network
• Internet Service Provider for example, AT&T, MCI, Sprint, EarthLink, MSN, GTE, etc.
• These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
• the computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

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