US20150042757A1 - Laser scanning systems and methods - Google Patents

Abstract

A three-dimensional scanner uses a rotatable mounting structure to secure a laser line source in a manner that permits rotation of a projected laser line about an axis of the laser, along with movement of the laser through an arc in order to conveniently position and orient the resulting laser line. Where the laser scanner uses a turntable or the like, a progressive calibration scheme may be employed with a calibration fixture to calibrate a camera, a turntable, and a laser for coordinated use as a three-dimensional scanner. Finally, parameters for a scan may be automatically created to control, e.g., laser intensity and camera exposure based on characteristics of a scan subject such as surface characteristics or color gradient.

Description

RELATED MATTERS
• This application claims the benefit of U.S. Prov. App. No. 61/864,158 filed on Aug. 9, 2013, U.S. Prov. App. No. 61/875,360 filed on Sep. 9, 2013, and U.S. Prov. App. No. 61/906,171 filed on Nov. 19, 2013. The content of each of these applications is hereby incorporated by reference in its entirety.
BACKGROUND
• There remains a need for improved techniques for three-dimensional scanning.
SUMMARY
• A three-dimensional scanner uses a rotatable mounting structure to secure a laser line source in a manner that permits rotation of a projected laser line about an axis of the laser, along with movement of the laser through an arc in order to conveniently position and orient the resulting laser line. Where the laser scanner uses a turntable or the like, a progressive calibration scheme may be employed with a calibration fixture to calibrate a camera, a turntable, and a laser for coordinated use as a three-dimensional scanner. Finally, parameters for a scan may be automatically created to control, e.g., laser intensity and camera exposure based on characteristics of a scan subject such as surface characteristics or color gradient.
BRIEF DESCRIPTION OF THE DRAWINGS
• The foregoing and other objects, features and advantages of the devices, systems, and methods described herein will be apparent from the following description of particular embodiments thereof, as illustrated in the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the devices, systems, and methods described herein.
• FIG. 1 shows a three-dimensional scanner.
• FIG. 2 shows a block diagram of a three-dimensional scanner system.
• FIG. 3 shows a perspective view of a device for aligning a laser.
• FIG. 4 shows a cross section of a laser housing.
• FIG. 5 shows a calibration component.
• FIG. 6 shows a method for calibrating a three-dimensional scanner.
• FIG. 7 shows a user interface for automatically selecting three-dimensional scan parameters.
• FIG. 8 shows a method for automatically selecting three-dimensional scan parameters.
DETAILED DESCRIPTION
• The embodiments will now be described more fully hereinafter with reference to the accompanying figures, in which preferred embodiments are shown. The foregoing may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these illustrated embodiments are provided so that this disclosure will convey the scope to those skilled in the art.
• All documents mentioned herein are hereby incorporated by reference in their entirety. References to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the text. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Thus, the term “or” should generally be understood to mean “and/or” and so forth.
• Recitation of ranges of values herein are not intended to be limiting, referring instead individually to any and all values falling within the range, unless otherwise indicated herein, and each separate value within such a range is incorporated into the specification as if it were individually recited herein. The words “about,” “approximately,” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose. Ranges of values and/or numeric values are provided herein as examples only, and do not constitute a limitation on the scope of the described embodiments. The use of any and all examples, or exemplary language (“e.g.,” “such as,” or the like) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the embodiments. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the embodiments.
• In the following description, it is understood that terms such as “first,” “second,” “top,” “bottom,” “above,” “below,” and the like, are words of convenience and are not to be construed as limiting terms.
• FIG. 1 shows a three-dimensional scanner. Thescanner100 may include aturntable102, one ormore lasers104, acamera106, and acontroller108.
• Theturntable102 may be any rotating surface such as a rigid plate or the like, which may be rotated to present various surfaces of an object on the turntable to thelasers104 and thecamera106.
• The one ormore lasers104 may be any lasers suitable for projecting lines onto an object that is being scanned on theturntable102. Thelasers104 can be 3.2 V line lasers or the like with 55 degree fans or any other laser or combination of lasers suitable for a three-dimensional scanning system.
• Thecamera106 can be a USB 2.0 Board Camera. While any resolution consistent with desired scan resolution may be used, a 1.3 MP or better color complementary metal-oxide semiconductor (CMOS) image sensor is cheaply commercially available and suitable for many applications. Thecamera106 can, for example, operate at 30 frames-per-second with a rolling shutter and a 12 inch focal distance. In another aspect, thecamera106 can operate at 7.5 frames-per-second. In other aspects, the camera can be any camera that can work in a three-dimensional scanning system. Thecamera106 can also take video footage and provide a video feed to a user device206 (as shown inFIG. 2) via a user interface. Thescanner100 can also include a red band-pass filter for thecamera106, which may be fixed or removable/replaceable. The filter may for example be a 25 mm or 27 mm removable and/or retractable 650 nmCW band pass filter with 40 nm pass band. The band-pass filter can remain on thecamera106 during scans for optimal scans. In another aspect, the band-pass filter can be removed for a scan.
• In general operation, an item can be placed on theturntable102. As the item rotates on theturntable102, thelasers104 can create laser lines that reflect off the object. Thecamera106 can take rapid photographs of the laser lines and a point cloud can be generated via thecontroller108 connected to thescanner100. Thecontroller108 can be electrically or otherwise coupled in a communicating relationship with theturntable102, thelasers104 and thecamera106. In general thecontroller108 is operable to control the components of thescanner100. Thecontroller108 may include any combination of software and/or processing circuitry suitable for controlling the various components of thescanner100 described herein including without limitation microprocessors, microcontrollers, application-specific integrated circuits, programmable gate arrays, and any other digital and/or analog components, as well as combinations of the foregoing, along with inputs and outputs for transceiving control signals, drive signals, power signals, sensor signals, and so forth. In one aspect, this may include circuitry directly and physically associated with thescanner100 such as an on-board processor. In another aspect, this may be a processor associated with a personal computer or other computing device (e.g., auser device206 as shown inFIG. 2) coupled to thescanner100, e.g., through a wired or wireless connection. Similarly, various functions described herein may be allocated between an on-board processor for thescanner100 and a separate computer. All such computing devices and environments are intended to fall within the meaning of the term “controller” or “processor” as used herein, unless a different meaning is explicitly provided or otherwise clear from the context.
• FIG. 2 shows a three-dimensional scanner system200. As shown inFIG. 2, thescanner100 can be coupled to auser device206 via a USB cable or any other connector used for locally connecting electronic devices to each other.
• Thescanner100 can alternatively or additionally be coupled to theuser device206 through adata network202. Thedata network202 may be any network(s) or internetwork(s) suitable for communicating data and control information among participants in theenvironment200. This may include public networks such as the Internet, private networks, telecommunications networks such as the Public Switched Telephone Network or cellular networks using third generation (e.g., 3G or IMT-2000), fourth generation (e.g., LTE (E-UTRA) or WiMax-Advanced (IEEE 802.16m)) and/or other technologies, as well as any of a variety of corporate area or local area networks and other switches, routers, hubs, gateways, and the like that might be used to carry data among participants
• Thescanner100 can include a network interface for connecting to thedata network202. The network interface may comprise, e.g., a network interface card, which term is used broadly herein to include any hardware (along with software, firmware, or the like to control operation of same) suitable for establishing and maintaining wired and/or wireless communications. The network interface card may include without limitation wired Ethernet network interface cards (“NICs”), wireless 802.11 networking cards, wireless 802.11 USB devices, or other hardware for wireless local area networking. The network interface may also or instead include cellular network hardware, wide area wireless network hardware or any other hardware for centralized, ad hoc, peer-to-peer, or other radio communications that might be used to carry data. In another aspect, the network interface may include a serial or USB port to directly connect to a computing device such as a desktop computer that, in turn, provides more general network connectivity to the data network.
• Theuser device206 may be a computing device such as a laptop computer, desktop computer, tablet, smart phone, or other computing device that can be operated by a user to provide a user input to control thescanner100. In another aspect, thescanner100 may be configured with a display, user input devices, and the like so that thescanner100 acts as theuser device206. The user input devices may include a display, buttons, or other physical user interface element(s) on thescanner100 that a user can interact with.
• Upon user input via theuser device206 and/or thescanner100, thescanner100 can begin analyzing the object that is placed on theturntable102 via thecontroller108. Once thecontroller108 creates a point cloud, theuser device206 can convert the point cloud into a viewable mesh that can be saved as a Thing file, STL, or other supported mesh formats. During each scan, the object can revolve on the turntable twice. The firstright laser104 can create a laser line that reflects off of the object during the first revolution and the secondleft laser104 can create a laser line that reflects off of the object during the second revolution. In another aspect, theleft laser104 can create a laser line that reflects off of the object during the first revolution and theright laser104 can create a laser line that reflects off of the object during the second revolution. In another aspect only one of the lasers can scan the object during the scan.
• After the scan, the information from thecamera106 or the two ormore lasers104 can be combined to create a point cloud. Theuser device206 can convert the point cloud into a continuous mesh via any combination of software and/or processing circuitry located on theuser device206.
• The three-dimensional scanner system200 can be used for scanning, calibration and automatically sending the scan data to a social networking platform hosted, e.g., on aserver204, which may be a general social networking platform or a special purpose platform dedicated to, e.g., three-dimensional printing, three-dimensional modeling, computer automated design, or the like.
• Theserver204 may include data storage, a network interface and a processor and/or or processing circuitry. In general, theserver204 may be configured to perform a variety of processing tasks related to the three-dimensional scanning of objects. For example, theserver204 may manage scan jobs received from one or more of theuser devices206, and provide related supporting functions such as content search and management. Theserver204 may also include a web server that provides web-based access by theuser device206 to the capabilities of theserver204. Theserver204 may also communicate periodically with thescanner100 in order to obtain status information concerning, e.g., the status of particular scan jobs, any of which may be subsequently presented to a user through the web server or any other suitable interface. Upon user input via the user interface on theuser device206, scanning can begin. The user input can first include clicking a physical or digital button to automatically back up the scans to theserver204 via thedata network202. The processor on theuser device206 or thescanner100 can prompt this user input either before the first scan of thescanner100 and/or before or after every scan.
• User input can be entered via the user interface on theuser device206 to initiate the scan. The user interface can prompt the user to place an object on theturntable102 in the correct position. For example, the user interface can prompt the user to place the object on the center of theturntable102. In another aspect the user interface can prompt the user to place the object on a positioning stand (not pictured). More generally, the user interface may provide step-by-step menus or other interactive elements to guide a user through a scanning procedure. A positioning stand can be used to secure objects that are not stable without support. The stand can also be used to elevate small objects or to secure an object in a specific orientation. The positioning stand can comprise a platform, a rod and one or more arms. A video feed can be shown via the user interface on theclient device206 to assist a user in a placement of an object.
• Once an object is placed, the user interface can prompt the user to start the scan. During the scan, the user interface can show the time remaining in the scan, a video feed of the object as it is being scanned, and or a point cloud assembly as it is being generated via thecontroller108. Once a scan is complete, a user can be given an option of cropping the scanned object model. Other post-scanning features such as smoothing, leveling, labeling (e.g., with three-dimensional text or the like), hole filling, and so forth may also be automatically or semi-automatically performed through the user interface. Once the model is completed, it can be (automatically or otherwise) shared with a social network, sent to a three-dimensional printer coupled to thescanner100 for printing, and/or exported for saving.
• In another aspect, the user interface can allow theuser device206 to take a picture of the object scanned and associate it with the three-dimensional model. For example a “Take a Photo” dialog can open and show a view of what thescanner100 sees via the camera. A prompt to slide the red band-pass filter away from the camera lens can be shown before the picture is taken.
• In general, thescanner100, theuser device206, or the controller108 (or any combination of these) may provide processing circuitry to control operation of the scanner systems contemplated herein, such as by performing the various processes and functions described below.
• FIG. 3 shows a device for aligning a laser. In general, a scanner may have one or more lasers, as noted above, which are preferably aligned to project a line or other pattern in a predetermined manner across a scanning volume. Thedevice300 may be used to align alaser302 so that a desired orientation may be obtained.
• In general, thelaser302 may be any of the lasers described above, or any other laser that can be configured to project a line or other pattern on a target of a scan. Thelaser302 may, for example, be a 3.2 Volt line laser, and/or the laser may have a 55 degree fan over which a laser line is projected. More generally, the pattern may be a line or the like, which may be obtained using an suitable optics, filters or the like to focus and direct light from the laser. Thelaser302 may have anaxis304 with an orientation that, when thelaser302 is placed for use in the device300 (which is in the scanner), directs thelaser302 toward a desired target, or more generally, in a desired direction. Additionally, thelaser302 and a line or other pattern from thelaser302 may have a rotational orientation about theaxis304. By rotating thelaser302 about theaxis304 as indicated by anarrow306, the rotational orientation of thelaser302 may be controlled.
• In general, alaser housing308 secures thelaser302 in a desired orientation within amount316. Thelaser housing308 may include acavity310 to receive thelaser302. Thelaser housing308 may also include atoothed wheel312 with a plurality ofteeth314 radially spaced about theaxis304 of thelaser302 when thelaser302 is placed for use in thecavity310.
• Amount316 for thelaser housing308 may include a base318 configured to be coupled to an external assembly such as a scanner housing. The base318 may include any suitable slots, tabs, registration features, screw holes, and the like, or any other suitable mechanism(s) for rigidly coupling to the external assembly in a fixed orientation. Aholder320 of themount316 may be configured to retain thelaser housing308 in a predetermined orientation while permitting rotation of the laser housing308 (and the laser302) about theaxis304 of thelaser302. Thelaser housing308 generally retains thelaser housing308 in rotational engagement about theaxis304 of thelaser302. Themount316 may further include ahinge322 that hingably couples the base318 to theholder320. Thelaser housing308 may be configured to snap-fit into themount316 where it may be retained by a number offingers340, flanges, or the like, or alternatively stated, themount316 may be configured to receive thelaser housing308 and retain thelaser housing308 with any of a variety of snap-fit mechanisms.
• One end of thelaser housing308 may form anadjustment wheel324 with the plurality ofteeth314 engaging another surface to secure thelaser housing308 in a desired rotational orientation. Theadjustment wheel324 may be operable as a thumb click wheel or the like, or asupplemental drive wheel325 may be provided for manual or automated activation. In general, theadjustment wheel324 is operable to rotate thelaser housing308 around theaxis304 of thelaser302. This rotation may be performed, e.g., by manually rotating theadjustment wheel324, or by rotating thesupplemental adjustment wheel325 with a motor or other electro-mechanical drive. Theadjustment wheel324 may be ratcheted or otherwise mechanically secured by the plurality ofteeth314 against free rotation after a desired rotational orientation has been established. Theadjustment wheel324 may be a click wheel that moves in discrete units of rotation accompanied by an audible or tactile click. The click wheel may be thumb operable, and may move in fixed increments such as three degree increments, or at any other suitable, regular intervals of rotation. The click wheel may click against a nub, spring, or the like on themount316.
• Anadjustment rod326 may also be provided that couples the base318 to theholder320 at a position away from thehinge322. In this configuration, theadjustment rod326 may be operable to displace the base318 relative to theholder320 along asecond axis330 of the adjustment rod. In this manner, thehinge322 is rotated (or hinged) thus moving theaxis304 of the laser relative to thebase318. Thus when thebase318 is fixed to an external support, theadjustment rod326 can be used to steer theaxis304 through an arc by flexing thehinge322. In one aspect, theadjustment rod326 may be a threaded rod that is threaded through a threadedinsert342 that is coupled to a fixed location such as a location in the base318 or in theholder320. By rotating the threaded rod, the threadedinsert342 may travel along the threaded rod, thus moving theholder320 relative to thebase318 and flexing thehinge322 to reorient thelaser302.
• Thelaser housing308 and themount316 may be formed of any suitable materials according to desired weight, strength, durability, and so forth. For example, thelaser housing308 and themount316 may be formed of an injection molded plastic and/or a plastic such as a polycarbonate acrylonitrile butadiene styrene or an acetal homopolymer.
• Themount316 may include aspring350 such as a coil spring or any other suitable compression spring or the like that urges theholder320 and the base318 into a predetermined relative orientation. Thisspring350 may thus bias thelaser302 toward a predetermined orientation relative to themount316 when thelaser302 is placed for use in thecavity310 of theholder320. While thespring350 may be a separate, discrete component, the spring may also or instead be a living plastic spring formed for example by a resilient material of thehinge322. The living plastic spring (or anyother spring350 as contemplated herein) may generally bias thelaser302 toward any predetermined position or orientation such as toward a predetermined position relative to themount316 when thelaser302 is placed for use in thecavity310.
• This configuration advantageously provides convenient positioning and rotation of a line laser within a scan volume with a relatively simple mechanical arrangement and a small number of moving parts. Additional adjustments may be necessary or desirable, and as such asupplemental positioning assembly360 may be provided in order to provide additional degrees of rotational or translational freedom for adjusting thelaser302. For example, thepositioning assembly360 may facilitate translation of theaxis304 within a plane perpendicular to theaxis304, or alignment of theaxis304 of thelaser302 with one or more additional degrees of freedom, that is, degrees of freedom not provided by themount316 andlaser housing308 described above. This may include any suitable fixture, set screws, and so forth, for adjusting position and orientation of the base318 relative to a fixed physical reference that thebase318 is attached to (such as a scanner housing). A variety of suitable mechanisms are known in the art and may be adapted for use as apositioning assembly360 as contemplated herein.
• FIG. 4 shows a cross section of a laser housing such as the laser housing described above. Thelaser housing400 may generally include acavity402 to receive a laser as described above. Thelaser housing400 may also include a plurality ofengagement elements404 such as ribs, fins, protrusions or the like within thecavity402 that secure a laser in a desired position and orientation within thecavity402. Theengagement elements404 may in general be shaped and sized in any suitable manner to hold a laser when the laser is positioned in the cavity. For example, theengagement elements404 may include ribs as illustrated, which may secure the laser with a press-fit or interference fit to frictionally engage the laser in the desired position. Asecond cavity406 may be included that is formed to receive a drive head such as a screw driver, hex wrench or the like. Thesecond cavity406 may be positioned within themount316 ofFIG. 3 such that thesecond cavity406 is accessible externally with a screw driver or the like to adjust the rotational orientation of the laser. Similarly, a portion of theadjustment wheel324 may be exposed outside a scanner housing to facilitate convenient manual adjustment.
• FIG. 5 shows a calibration component. In general, a scanner such as any of the scanners described herein may be calibrated prior to use in order to obtain more accurate scan results. In general, this involves placing a calibration component such as thecalibration component500 shown inFIG. 5 onto the turntable of a scanner and capturing images in a variety of poses and under a variety of lighting conditions.
• In one aspect, thecalibration component500 may be a multi-part component that can be configured to present a variety of different surfaces, patterns and the like. For example, as illustrated, thecalibration component500 may have a base502 with angled surfaces and a checkerboard pattern or the like, as well as aremovable plate504 that can be removed from and replaced to the base502 to provide a horizontal surface for calibration-related data acquisition. While a checkerboard is shown as thecalibration pattern506, it will be understood that a variety of calibration patterns may also or instead be employed including, without limitation a dot grid, a line grid, a random pattern, and so forth. Thecalibration pattern506 may also or instead include a predetermined three-dimensional shape of thecalibration component500, such as the angled surfaces of thebase502.
• In one aspect, thecalibration component500 may include a plurality of surfaces. This may include at least threepanels510,512,514 each including the calibration pattern506 (i.e., the same pattern) or different calibration patterns, or some combination of these. Thecalibration component500 may also include two different faces such as a first face formed by one of thepanels510, and a second face formed by theother panels512,514. As noted above, one of thepanels510 may be removable and the face of thefirst panel510 may occlude the calibration pattern on theother panels512,514 when attached to thebase502. This permits a single calibration fixture to provide various different patterns and three-dimensional shapes to facilitate various calibration steps as discussed below.
• Thecalibration component500 may include atab516 or other protrusion or the like configured to couple thecalibration component500, or thebase502 of thecalibration component500, to a turntable or other base for a scanning system in order to retain thecalibration component500 in a predetermined position and orientation during calibration. Any other number of tabs may be provided to secure thecalibration component500, or the base502 or one of thepanels510,512,514 in a desired orientation for use in calibrating a scanner.
• FIG. 6 shows a method for calibrating a three-dimensional scanner. In general a multi-configuration calibration component may provide a variety of configurable and positionable surfaces that can be used in different calibration steps. With this calibration component, a progressive calibration of a camera, a turntable, and a laser may be performed. Configuration and positioning of the calibration component may be orchestrated by a user interface that interactively guides a user through various positioning and configuration steps.
• As shown instep602, themethod600 may begin with receiving user input including a request to initiate calibration of a three-dimensional scanner. The three-dimensional scanner may include a turntable, a laser, and a camera as generally described above. The request may be received, for example, from a user through a user interface, which may be a user interface rendered on the scanner or any suitable device coupled to the scanner such as a local desktop or laptop computer.
• As shown instep604, themethod600 may include providing information to the user for positioning a calibration component on the turntable in a first position for camera calibration. The calibration component may be any of the calibration components described herein, and may for example include a plurality of surfaces with at least two of the plurality of surfaces include calibration patterns. The information may be provided, for example, by displaying instructions to the user in the user interface. The instructions may specify a configuration of the calibration component, particularly where the component has removable surfaces or other multiple configurations, and may more specifically identify slots, tabs or the like on the turntable where the calibration component should be placed.
• As shown instep606, themethod600 may include receiving an indication that the calibration component is properly positioned on the turntable for camera calibration. This confirmation may be received, for example by a user pressing a button on the scanner or operating a control in the user interface (after suitably placing the component). Placement may also or instead be confirmed automatically or semi-automatically by capturing and analyzing images from the uncalibrated camera(s). Thus receiving the indication that the calibration component is properly positioned or configured may in general include receiving a manual user input, receiving a computer generated input such as an input from a computer vision system, or some combination of these.
• As shown instep608, themethod600 may include rotating the turntable about a rotation axis thereby rotating the calibration component.
• As shown instep610, themethod600 may include capturing images of the calibration component on the turntable with the camera as the turntable is rotating, thereby providing a first plurality of images. This may include capturing video images, or capturing still images at a predetermined rate, e.g., at particular time intervals or at particular rotational intervals of the turntable.
• As shown instep612, themethod600 may include performing a first calibration calculation with the first plurality of images to calibrate the camera, thereby providing a calibrated camera. Camera calibration is a necessary step in three-dimensional processing to facilitate extraction of three-dimensional data from two-dimensional images. A variety of suitable techniques are known and well characterized in the art, and these techniques are not repeated here except to note generally that known features and/or displacements can be used to recover three-dimensional characteristics or parameters of a camera system in a manner that permits subsequent three-dimensional measurements with improved accuracy.
• As shown instep614, themethod600 may include providing information to the user for positioning the calibration component on the turntable for turntable calibration. This may also or instead include providing information to reconfigure the calibration component, e.g., by adding or removing a panel, or by changing a position or orientation of a panel or other element of the calibration component. The information may be provided, for example, by displaying instructions to the user in the user interface. The instructions may specify a configuration of the calibration component, particularly where the component has removable surfaces or other multiple configurations, and may more specifically identify slots, tabs or the like on the turntable where the calibration component should be placed.
• As shown in step616, themethod600 may include receiving an indication that the calibration component is properly positioned for turntable calibration. This confirmation may be received, for example by a user pressing a button on the scanner or operating a control in the user interface. Placement may additionally be confirmed automatically or semi-automatically by capturing and analyzing images from the camera(s). Thus receiving the indication that the calibration component is properly positioned or configured may in general include receiving a manual user input, receiving a computer generated input such as an input from a computer vision system, or some combination of these.
• As shown in step618, once the calibration component is properly positioned for turntable calibration, themethod600 may include rotating the turntable about the rotation axis thereby rotating the calibration component.
• As shown instep620, themethod600 may include capturing a second plurality of images of the calibration pattern included on at least one of the plurality of surfaces of the calibration component using the calibrated camera. This may include capturing video images, or capturing still images at a predetermined rate, e.g., at particular time intervals or at particular rotational intervals of the turntable.
• As shown instep622, themethod600 may include determining locations of predetermined points on the calibration pattern using the captured images. This may be, e.g., corners of the calibration pattern on the calibration component, or other interstitial locations within the checkerboard pattern or the like. In one aspect, determining locations may include using computer vision to determine the corners of the checkerboard or any other suitable feature or location within a calibration pattern.
• As shown instep624, themethod600 may include determining a rotational position of the rotation axis of the turntable with respect to the camera based upon the locations of the predetermined points, thereby providing a calibrated turntable. In this manner the turntable may be calibrated so that it can produce accurate, controllable rotational orientations. As noted above, a variety of calibration techniques are known in the art that may be suitably adapted for use in providing a calibrated turntable as contemplated herein. By way of example and not of limitation, determining the rotational position of the rotation axis of the turntable with respect to the camera may include computing centers for circles created by rotation of the predetermined points of the calibration pattern about the rotation axis and averaging the centers to determine an average center representing the rotational position of the rotation axis.
• As shown instep626, themethod600 may include providing information to the user for positioning the calibration component on the turntable in a third position (and/or configuration) for laser calibration. The third position may include the calibration component oriented such that the calibration patterns of the at least two of the plurality of surfaces are non-planar with respect to each other and are disposed in a field of view of the calibrated camera. For example, by removing a horizontal panel to expose to non-planar panels such as those described above with reference toFIG. 5, a suitable calibration surface may be presented. Thus in one aspect, the calibration component may include a removable panel that is removed to configure the calibration component for laser calibration.
• As shown in step628, themethod600 may include receiving an indication from the user that the calibration component is properly positioned for laser calibration. This confirmation may be received, for example by a user pressing a button on the scanner or operating a control in the user interface. Placement may additionally be confirmed automatically or semi-automatically by capturing and analyzing images from the camera(s). Thus receiving the indication that the calibration component is properly positioned or configured may in general include receiving a manual user input, receiving a computer generated input such as an input from a computer vision system, or some combination of these.
• As shown instep630, themethod600 may include directing a beam of the laser on the calibration patterns of the calibration component in the field of view of the calibrated camera.
• As shown instep632, themethod600 may include capturing a third plurality of images of the beam on the calibration patterns of the calibration component.
• As shown instep634, themethod600 may include performing a calibration calculation for the laser based on the third plurality of images, thereby providing a calibrated laser. This may generally include any suitable calibration calculations for improving accuracy of the laser in terms of, e.g., focus, position, intensity, or any other controllable aspect of the laser.
• As shown in step636, themethod600 may include removing the calibration component from the turntable so that a scanning volume is available for a scan target.
• As shown instep638, themethod600 may include capturing a scan of an object with the calibrated camera, the calibrated turntable, and the calibrated laser.
• FIG. 7 shows auser interface700 for automatically selecting three-dimensional scan parameters. When operating a three-dimensional scanner such as a scanner with a turntable, laser, and camera as described herein, the optical properties of a scan target can significantly influence scan results. However, a user may not be able to readily balance, e.g., laser output parameters and camera exposure parameters to achieve the best results. To assist a user in selecting the best parameters, a semi-automated process may be provided that permits a user to specify various optical properties such as shade, color and surface texture. The scanner (or other processing circuitry associated with the scanner, such as a locally coupled computer) may then automatically select specific operating parameters for the scanner components based on the user-provided description of an object's optical properties. While theuser interface700 ofFIG. 7 specifically depicts a user selection of one of three possible shades (light, medium, dark), it will be understood that any other user-perceptible optical characteristics may also or instead be used including without limitation surface texture, opacity, transparency, glossiness, and so forth.
• FIG. 8 shows a method for automatically selecting three-dimensional scan parameters. In general, themethod800 may include receiving user selections of various optical properties, and then adjusting specific system parameters according to the user-provided information.
• As shown instep802, themethod800 may begin with providing a first prompt in a user interface configured to receive a user input selecting a color gradient that best matches an object to be scanned by the three-dimensional scanner. The color gradient may, for example, include a shade selected from a group consisting of light, medium, and dark, or any other suitable categories at any desired level of granularity or detail.
• As shown instep804, themethod800 may include providing manual decision support to a user in the user interface. For example, a decision may be assisted with any of a variety of visual aids for the user. For example, with a color gradient of two or more shades, this step may include displaying examples of each of the two or more shades to assist the user in selecting the color gradient at the first prompt. This step may further include displaying a video feed of the object to be scanned for a direct, on-screen comparison of the object to the examples within the user interface.
• As shown instep806, themethod800 may also or instead include providing automated decision support to a user. For example, this may include capturing an image of the object that is to be scanned, and performing a comparison of the image to a number of images of previously scanned objects using, for example, any of a variety of similarity measures or the like. In a semi-automated mode, the method may include providing relevant information to a user, such as by presenting a selection of a color gradient or surface characteristic that resulted in a successful scan of one or more of the previously scanned objects. Alternatively, the method may proceed fully automatically, e.g., by automatically selecting a color gradient or a surface characteristic for a scan based on the comparison when one of the number of images appears to include closely corresponding optical properties.
• As shown instep808, themethod800 may include providing a second prompt in the user interface configured to receive a user input selecting a surface characteristic that best matches a surface of the object to be scanned, the surface characteristic including at least one of glossiness, fuzziness, and texture.
• As shown in step810, themethod800 may include adjusting camera parameters based on the color gradient and the surface characteristic thereby adjusting an exposure of the camera. For example, this may include adjusting a shutter speed and a lens aperture of the camera to suitable selections best matched to the characteristics of the object. For example, where the color gradient is light, the camera may be responsively adjusted to a lower exposure. Where the color gradient is dark, the camera may be responsively adjusted to a higher exposure. In another aspect, a fixed exposure may be maintained independent of the color gradient, but the exposure may vary in response to other factors such as a color composition or surface texture.
• As shown in step812, themethod800 may include adjusting an intensity of the laser based on the color gradient and the surface characteristic. For example, where the color gradient is light, the laser may be responsively adjusted to a higher intensity. Where the color gradient id dark, the laser may be responsively adjusted to a lower intensity. In another aspect, a fixed laser intensity may be maintained independent of the color gradient, but the laser intensity may vary in response to other factors such as a color composition or surface texture.
• As shown instep814, themethod800 may include scanning an object using the adjusted laser and camera parameters.
• The above systems, devices, methods, processes, and the like may be realized in hardware, software, or any combination of these suitable for the control, data acquisition, and data processing described herein. This includes realization in one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors or other programmable devices or processing circuitry, along with internal and/or external memory. This may also, or instead, include one or more application specific integrated circuits, programmable gate arrays, programmable array logic components, or any other device or devices that may be configured to process electronic signals. It will further be appreciated that a realization of the processes or devices described above may include computer-executable code created using a structured programming language such as C, an object oriented programming language such as C++, or any other high-level or low-level programming language (including assembly languages, hardware description languages, and database programming languages and technologies) that may be stored, compiled or interpreted to run on one of the above devices, as well as heterogeneous combinations of processors, processor architectures, or combinations of different hardware and software. At the same time, processing may be distributed across devices such as the various systems described above, or all of the functionality may be integrated into a dedicated, standalone device. All such permutations and combinations are intended to fall within the scope of the present disclosure.
• Embodiments disclosed herein may include computer program products comprising computer-executable code or computer-usable code that, when executing on one or more computing devices, performs any and/or all of the steps of the control systems described above. The code may be stored in a non-transitory fashion in a computer memory, which may be a memory from which the program executes (such as random access memory associated with a processor), or a storage device such as a disk drive, flash memory or any other optical, electromagnetic, magnetic, infrared or other device or combination of devices. In another aspect, any of the control systems described above may be embodied in any suitable transmission or propagation medium carrying computer-executable code and/or any inputs or outputs from same.
• It will be appreciated that the devices, systems, and methods described above are set forth by way of example and not of limitation. Numerous variations, additions, omissions, and other modifications will be apparent to one of ordinary skill in the art. In addition, the order or presentation of method steps in the description and drawings above is not intended to require this order of performing the recited steps unless a particular order is expressly required or otherwise clear from the context.
• The method steps of the implementations described herein are intended to include any suitable method of causing such method steps to be performed, consistent with the patentability of the following claims, unless a different meaning is expressly provided or otherwise clear from the context. So for example performing the step of X includes any suitable method for causing another party such as a remote user, a remote processing resource (e.g., a server or cloud computer) or a machine to perform the step of X. Similarly, performing steps X, Y and Z may include any method of directing or controlling any combination of such other individuals or resources to perform steps X, Y and Z to obtain the benefit of such steps. Thus method steps of the implementations described herein are intended to include any suitable method of causing one or more other parties or entities to perform the steps, consistent with the patentability of the following claims, unless a different meaning is expressly provided or otherwise clear from the context. Such parties or entities need not be under the direction or control of any other party or entity, and need not be located within a particular jurisdiction.
• It will be appreciated that the methods and systems described above are set forth by way of example and not of limitation. Numerous variations, additions, omissions, and other modifications will be apparent to one of ordinary skill in the art. In addition, the order or presentation of method steps in the description and drawings above is not intended to require this order of performing the recited steps unless a particular order is expressly required or otherwise clear from the context. Thus, while particular embodiments have been shown and described, it will be apparent to those skilled in the art that various changes and modifications in form and details may be made therein without departing from the spirit and scope of this disclosure and are intended to form a part of the invention as defined by the following claims, which are to be interpreted in the broadest sense allowable by law.

Claims (20)

What is claimed is:

1. A method for calibrating a three-dimensional scanner comprising:

receiving a user input from a user through a user interface of a three-dimensional scanner, the user input including a request to initiate calibration of the three-dimensional scanner, the three-dimensional scanner including a turntable, a laser, and a camera;

providing information to the user for positioning a calibration component on the turntable in a first position for camera calibration, the calibration component including a plurality of surfaces, wherein at least two of the plurality of surfaces include calibration patterns;

receiving an indication that the calibration component is properly positioned for camera calibration;

rotating the turntable about a rotation axis thereby rotating the calibration component;

capturing images of the calibration component on the turntable with the camera as the turntable is rotating, thereby providing a first plurality of images;

performing a first calibration calculation with the first plurality of images to calibrate the camera, thereby providing a calibrated camera;

providing information to the user for positioning the calibration component on the turntable in a second position for turntable calibration;

receiving an indication that the calibration component is properly positioned for turntable calibration;

rotating the turntable about the rotation axis thereby rotating the calibration component;

capturing a second plurality of images of the calibration pattern included on at least one of the plurality of surfaces of the calibration component using the calibrated camera;

determining locations of predetermined points on the calibration pattern using the captured images;

determining a rotational position of the rotation axis of the turntable with respect to the camera based upon the locations of the predetermined points, thereby providing a calibrated turntable;

providing information to the user for positioning the calibration component on the turntable in a third position for laser calibration, the third position including the calibration component oriented such that the calibration patterns of the at least two of the plurality of surfaces are non-planar with respect to each other and are disposed in a field of view of the calibrated camera;

receiving an indication from the user that the calibration component is properly positioned for laser calibration;

directing a beam of the laser on the calibration patterns of the calibration component in the field of view of the calibrated camera;

capturing a third plurality of images of the beam on the calibration patterns of the calibration component; and

performing a calibration calculation for the laser based on the third plurality of images, thereby providing a calibrated laser.

2. The method ofclaim 1 further comprising capturing a scan of an object with the calibrated camera, the calibrated turntable, and the calibrated laser.

3. The method ofclaim 1 wherein the calibration pattern includes at least one of a checkerboard pattern, a dot grid, and a line grid.

4. The method ofclaim 1 wherein the calibration pattern includes a predetermined three-dimensional shape of the calibration component.

5. The method ofclaim 1 wherein the predetermined points are corners of the calibration pattern.

6. The method ofclaim 1 wherein determining the rotational position of the rotation axis of the turntable with respect to the camera includes computing centers for circles created by rotation of the predetermined points of the calibration pattern about the rotation axis and averaging the centers to determine an average center representing the rotational position of the rotation axis.

7. The method ofclaim 1 wherein the plurality of surfaces include at least three panels and at least two faces, wherein the at least three panels include the calibration patterns.

8. The method ofclaim 7 wherein at least one of the at least three panels is removable and wherein laser calibration further includes removing the front panel.

9. The method ofclaim 7 wherein a face occludes the calibration pattern included on at least one of the at least three panels.

10. The method ofclaim 1 wherein the calibration component includes a tab configured to couple the calibration component to the turntable.

11. The method ofclaim 1 wherein the calibration pattern includes a checkerboard, the method further comprising using computer vision to determine the corners of the checkerboard.

12. The method ofclaim 1 further comprising removing the calibration component from the turntable.

13. The method ofclaim 1 wherein receiving an indication that the calibration component is properly positioned for camera calibration includes receiving a manual user input.

14. The method ofclaim 1 wherein receiving an indication that the calibration component is properly positioned for camera calibration includes receiving an input from a computer vision system.

15. The method ofclaim 1 wherein receiving an indication that the calibration component is properly positioned for turntable calibration includes receiving a manual user input.

16. The method ofclaim 1 wherein receiving an indication that the calibration component is properly positioned for turntable calibration includes receiving an input from a computer vision system.

17. A computer program product for calibrating a three-dimensional scanner, the computer program product comprising non-transitory computer executable code embodied in a non-transitory computer readable medium that, when executing on a three-dimensional scanner, performs the steps of:

receiving a user input from a user through a user interface of a three-dimensional scanner, the user input including a request to initiate calibration of the three-dimensional scanner, the three-dimensional scanner including a turntable, a laser, and a camera;

providing information to the user for positioning a calibration component on the turntable in a first position for camera calibration, the calibration component including a plurality of surfaces, wherein at least two of the plurality of surfaces include calibration patterns;

receiving an indication that the calibration component is properly positioned for camera calibration;

rotating the turntable about a rotation axis thereby rotating the calibration component;

capturing images of the calibration component on the turntable with the camera as the turntable is rotating, thereby providing a first plurality of images;

performing a first calibration calculation with the first plurality of images to calibrate the camera, thereby providing a calibrated camera;

providing information to the user for positioning the calibration component on the turntable in a second position for turntable calibration;

receiving an indication that the calibration component is properly positioned for turntable calibration;

rotating the turntable about the rotation axis thereby rotating the calibration component;

capturing a second plurality of images of the calibration pattern included on at least one of the plurality of surfaces of the calibration component using the calibrated camera;

determining locations of predetermined points on the calibration pattern using the captured images;

determining a rotational position of the rotation axis of the turntable with respect to the camera based upon the locations of the predetermined points, thereby providing a calibrated turntable;

providing information to the user for positioning the calibration component on the turntable in a third position for laser calibration, the third position including the calibration component oriented such that the calibration patterns of the at least two of the plurality of surfaces are non-planar with respect to each other and are disposed in a field of view of the calibrated camera;

receiving an indication from the user that the calibration component is properly positioned for laser calibration;

directing a beam of the laser on the calibration patterns of the calibration component in the field of view of the calibrated camera;

capturing a third plurality of images of the beam on the calibration patterns of the calibration component; and

performing a calibration calculation for the laser based on the third plurality of images, thereby providing a calibrated laser.

18. The computer program product ofclaim 17 further comprising code that performs the step of capturing a scan of an object with the calibrated camera, the calibrated turntable, and the calibrated laser.

19. The computer program product ofclaim 17 wherein the calibration pattern includes at least one of a checkerboard pattern, a dot grid, and a line grid.

20. A device comprising a three dimensional scanner and processing circuitry programmed to perform the steps of:

receiving a user input from a user through a user interface of a three-dimensional scanner, the user input including a request to initiate calibration of the three-dimensional scanner, the three-dimensional scanner including a turntable, a laser, and a camera;

providing information to the user for positioning a calibration component on the turntable in a first position for camera calibration, the calibration component including a plurality of surfaces, wherein at least two of the plurality of surfaces include calibration patterns;

receiving an indication that the calibration component is properly positioned for camera calibration;

rotating the turntable about a rotation axis thereby rotating the calibration component;

capturing images of the calibration component on the turntable with the camera as the turntable is rotating, thereby providing a first plurality of images;

performing a first calibration calculation with the first plurality of images to calibrate the camera, thereby providing a calibrated camera;

providing information to the user for positioning the calibration component on the turntable in a second position for turntable calibration;

receiving an indication that the calibration component is properly positioned for turntable calibration;

rotating the turntable about the rotation axis thereby rotating the calibration component;

capturing a second plurality of images of the calibration pattern included on at least one of the plurality of surfaces of the calibration component using the calibrated camera;

determining locations of predetermined points on the calibration pattern using the captured images;

determining a rotational position of the rotation axis of the turntable with respect to the camera based upon the locations of the predetermined points, thereby providing a calibrated turntable;

providing information to the user for positioning the calibration component on the turntable in a third position for laser calibration, the third position including the calibration component oriented such that the calibration patterns of the at least two of the plurality of surfaces are non-planar with respect to each other and are disposed in a field of view of the calibrated camera;

receiving an indication from the user that the calibration component is properly positioned for laser calibration;

directing a beam of the laser on the calibration patterns of the calibration component in the field of view of the calibrated camera;

capturing a third plurality of images of the beam on the calibration patterns of the calibration component; and

performing a calibration calculation for the laser based on the third plurality of images, thereby providing a calibrated laser.

Images