Patent Application
20130141433
The present application relates generally to imaging, and more particularly to, methods, systems and computer program products for creating three dimensional (3D) meshes of 2D images.
Creating three dimensional (3D) models from monocular two dimensional (2D) images presents a difficult problem. Computer-aided imagery is the process of rendering new 2D and 3D images of an object or a scene (hereinafter collectively “object”) on a terminal screen or graphical user interface from two or more digitized 2D images with the assistance of the processing and data handling capabilities of a computer. Constructing a 3D model from 2D images may be utilized, for example, in computer-aided design (CAD), 3D teleshopping, and virtual reality systems, in which the goal of the processing is a graphical 3D model of a scene that was originally represented only by a finite number of 2D images. The 2D images from which the 3D model is constructed represent views of the object as perceived from different views or locations around the object. The images can be obtained using multiple cameras positioned around the object or scene, a single camera in motion around the object or scene, a camera array and the like. The information in the 2D images is combined and contrasted to produce a composite, computer-based graphical 3D model.
One current method of reconstructing a graphical 3D model of a scene using multiple 2D images is a depth map. A depth map is a 2D array of values for mathematically representing a surface in space, where the rows and columns of the array correspond to the x and y location information of the surface and the array elements are depth or distance readings to the surface from a given point or camera location. A depth map can be viewed as a grey scale image of an object, with the depth information replacing the intensity and color information, or pixels, at each point on the surface of the object. A graphical representation of an object can be estimated by a depth map. However, the accuracy of a depth map declines as the distances to the objects increase.
Other algorithms have been developed to create more accurate 3D models from 2D images. For example, texture based algorithms may be used to convert a still 2D image into a 3D model. One of these products is Make3D created by professors at Stanford University. However, the accuracy of the resulting 3D models still deteriorates after a certain distance.
Some embodiments of the present inventive concept provide methods for obtaining a three-dimensional (3D) mesh from two dimensional images. The method includes obtaining a series of 2D images using a camera array; calculating a depth map using the obtained series of 2D images; identifying portions of the calculated depth map that need additional detail; applying a textured based algorithm to the identified portions of the calculated depth map to obtain the additional detail in the depth map; and combining the calculated depth map with the obtained additional detail to provide a more accurate 3D mesh, wherein at least one of the obtaining, calculating, identifying, applying and combining are implemented by at least one processor.
In further embodiments, the camera array may be one of a matrix of 4×4 camera and a matrix of 4×5 cameras.
In still further embodiments, the camera array may be included in a computational camera of a wireless communication device.
In some embodiments, identifying portions of the calculated depth map may include marking regions in the depth map having a distance greater than d, where d is the distance into the depth map defining when the additional detail is needed.
In further embodiments, applying a texture based algorithm may include applying a texture based algorithm to the regions marked to obtain an improved mesh for the marked regions.
In still further embodiments, combining may further include combining the calculated depth map and the improved mesh for the marked regions to obtain the more accurate 3D mesh.
In some embodiments, combining may be preceded by assigning a higher weight to the improved mesh for the marked regions of the depth map for regions with a distance greater than d; and assigning a higher weight to calculated depth map for regions in the depth map having a distance less than d.
Further embodiments of the present inventive concept provide a system for obtaining a three-dimensional (3D) mesh of two-dimensional (2D) images. The system may include a camera configured to obtain a series of 2D images using a camera array and a processor. The processor includes a depth map module configured to calculate a depth map using the obtained series of 2D images; a refinement module configured to identify portions of the calculated depth map that need additional detail; and a texture based acquisition module configured to apply a textured based algorithm to the identified portions of the calculated depth map to obtain the additional detail, wherein the refinement module is further configured to combine the calculated depth map with the obtained additional detail to provide a more accurate 3D mesh of the obtained series of 2D images.
Still further embodiments of the present inventive concept provide a computer program product for obtaining a three-dimensional (3D) mesh from two dimensional images. The computer program product includes a non-transitory computer readable storage medium including computer readable program code embodied therein. The computer readable program code includes computer readable program code configured to obtain a series of 2D images using a camera array; computer readable program code configured to calculate a depth map using the obtained series of 2D images; computer readable program code configured to identify portions of the calculated depth map that need additional detail; computer readable program code configured to apply a textured based algorithm to the identified portions of the calculated depth map to obtain the additional detail in the depth map; and computer readable program code configured to combine the calculated depth map with the obtained additional detail to provide a more accurate 3D mesh.
Other methods, systems and/or computer program products according to embodiments of the inventive concept will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such additional methods, systems and/or computer program products be included within this description, be within the scope of the present inventive concept, and be protected by the accompanying claims. Moreover, it is intended that all embodiments disclosed herein can be implemented separately or combined in any way and/or combination.
The accompanying drawings, which are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of this application, illustrate certain embodiment(s) of the inventive concept. In the drawings:
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present inventive concept. However, it will be understood by those skilled in the art that the present inventive concept may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present inventive concept.
As discussed above, creating three dimensional (3D) models from monocular two dimensional (2D) images presents a difficult problem. The existing texture based algorithms, for example, Make 3D, and the depth maps from array cameras do not provide an adequate solution. For example, the accuracy of the depth map from an array camera declines as distances to the objects increase. This is due to the fact that there is a limited length between the cameras and the length between the cameras sets the possible resolution in determining the distance to the object. The human mind is trained to recognize far off objects and interpret the shapes and 3D properties depending on features such as textures, colors etc.
To address the issues with conventional methods, some embodiments of the present inventive concept combine aspects of the depth map method and the texture based algorithm to provide an improved 3D mesh. In particular, some embodiments of the present inventive concept use a depth map generated by a computational camera to identify areas that in the 3D image that need more detail and, then, fill in these areas using a texture based algorithm as will be discussed further herein with respect to
Referring first to
The camera 124, for example, a camera array, may be used to obtain a series of 2D images, which may be supplied to the processor 127 of the communications device 110. The camera 124 may be a matrix of, for example, 4×4 or 4×5 cameras, without departing from the scope of the present inventive concept.
The processor 127 may be configured to generate a larger image from the 2D images and generated a depth map from the larger image. Methods of generating a depth map are known to those of skill in the art. Any method may be used without departing from the scope of the inventive concept.
The processor 127 may be further configured to identify portions of the 3D mesh that may need more detail. As discussed above, after a certain distance, for example, 2.0-3.0 meters, the accuracy of the 3D image created using the depth map declines. Thus, in some embodiments, a threshold function may be used to mark the regions identified as needing more detail. For example, anything in the 3D mesh having a distance greater than 2.0 meters may be “marked” as needing more detail. It will be understood that the distance at which the image degrades is related to the physical dimension of the array camera being used. Accordingly, smaller cameras may have a smaller distance threshold and, similarly, larger cameras may have a larger distance threshold.
Some embodiments of the present inventive concept can tolerate some degradation in quality without requiring additional details. For example, if the accuracy of the 3D mesh is between 90-95 percent this may be tolerated. However, anything less than 90 percent accurate may be marked as needing more detail. Thus, in some embodiments, a threshold function is used to mark regions with a distance d>Td, where Td depends on the accuracy in the depth map.
The processor 127 may be further configured to use a texture based algorithm, for example, Make 3D, to provide the details in the regions marked as needing more detail. In other words, the textured based algorithm may be used to fill in the missing details the depth map. Although embodiments of the present inventive concept discuss the use of Make 3D, embodiments are not limited this configuration. Any texture based algorithm may be used without departing from the scope of the present inventive concept.
Finally, the processor 127 may be configured to combine the depth map mesh and the texture based mesh to produce an improved 3D mesh 160 of the object or scene. In some embodiments, the two meshes may be weighted depending on the calculated accuracy of the mesh, for example, assigning a higher weight to the texture based mesh for distances greater than d and assigning a higher weight to the depth map (camera array) mesh for distances less than d. As discussed above, the distance d is defined as the distance where accuracy becomes less than 90 percent. It will be understood that the distance at which the image degrades is related to the physical dimension of the array camera being used. Accordingly, smaller cameras may have a smaller distance threshold and, similarly, larger cameras may have a larger distance threshold.
Referring now to
In particular, the processor 227 can be any commercially available or custom microprocessor, microcontroller, digital signal processor or the like. The memory 295 May include any memory devices containing the software and data used to implement the functionality circuits or modules used in accordance with embodiments of the present inventive concept. The memory 295 can include, but is not limited to, the following types of devices: cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, DRAM and magnetic disk. In some embodiments of the present inventive concept, the memory 295 may be a content addressable memory (CAM).
As further illustrated in
As further illustrated in
In particular, the depth map module 253 is configured obtain a lager image from the series of 2D images obtained using the camera array (124
In some embodiments, the refinement module 255 is configured to mark regions in the depth map having a distance greater than a distance d, where the distance d is the distance into the depth map defining when the additional detail is needed. As discussed above, in some embodiments this distance is from about 2.0 to about 3.0 meters. This may the distance when the accuracy degrades to below 90 percent in some embodiments.
In further embodiments, the refinement module 255 may be further configured to assign a higher weight to the improved mesh for the marked regions of the depth map for regions with a distance greater than d and assign a higher weight to the calculated depth map for regions in the depth map having a distance less than d.
Referring now to
The transceiver 340 may include transmit/receive circuitry (TX/RX) that provides separate communication paths for supplying/receiving RF signals to different radiating elements of the antenna system 300 via their respective RF feeds.
The transceiver 340 in operational cooperation with the processor 327 may be configured to communicate according to at least one radio access technology in two or more frequency ranges. The at least one radio access technology may include, but is not limited to, WLAN (e.g., 802.11), WiMAX (Worldwide Interoperability for Microwave Access), TransferJet, 3GPP LTE (3rd Generation Partnership Project Long Term Evolution), Universal Mobile Telecommunications System (UMTS), Global Standard for Mobile (GSM) communication, General Packet Radio Service (GPRS), enhanced data rates for GSM evolution (EDGE), DCS, PDC, PCS, code division multiple access (CDMA), wideband-CDMA, and/or CDMA2000. Other radio access technologies and/or frequency bands can also be used in embodiments according to the inventive concept.
Referring now to the flowchart of
A depth map is calculated using the obtained series of 2D images (block 410). In particular, the series of 2D images are used to generate a larger image and the depth map is generated from the larger image. Portions of the calculated depth map that need additional detail are identified (block 420). In some embodiments, the portions of the calculated depth map may be identified by marking regions in the depth map having a distance greater than d, where d is the distance into the depth map defining when the additional detail is needed. A textured based algorithm is applied to the identified portions of the calculated depth map to obtain the additional detail (block 430). The calculated depth map is combined with the obtained additional detail to provide a more accurate 3D mesh of the obtained series of 2D images (block 440).
In some embodiments, a higher weight may be assigned to the improved mesh for the marked regions of the depth map for regions with a distance greater than d and a higher weight may be assigned to calculated depth map for regions in the depth map having a distance less than d.
Various embodiments were described herein with reference to the accompanying drawings, in which embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art.
It will be understood that, when an element is referred to as being “connected”, “coupled”, “responsive”, or variants thereof to another element, it can be directly connected, coupled, or responsive to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected”, “directly coupled”, “directly responsive”, or variants thereof to another element, there are no intervening elements present. Furthermore, “coupled”, “connected”, “responsive”, or variants thereof as used herein may include wirelessly coupled, connected, or responsive. Like numbers refer to like elements throughout. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the inventive concept. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Well-known functions or constructions may not be described in detail for brevity and/or clarity.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present inventive concept. Moreover, as used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense expressly so defined herein.
As used herein, the terms “comprise”, “comprising”, “comprises”, “include”, “including”, “includes”, “have”, “has”, “having”, or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof. Furthermore, if used herein, the common abbreviation “e.g.”, which derives from the Latin phrase exempli gratia, may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. If used herein, the common abbreviation “i.e.”, which derives from the Latin phrase id est, may be used to specify a particular item from a more general recitation.
Exemplary embodiments were described herein with reference to block diagrams and/or flowchart illustrations of computer-implemented methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits. These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit such as a digital processor, and/or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions/acts specified in the block diagrams and/or flowchart block or blocks, and thereby create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block(s). These computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus 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 functions/acts specified in the block diagrams and/or flowchart block or blocks.
A tangible, non-transitory computer-readable medium may include an electronic, magnetic, optical, electromagnetic, or semiconductor data storage system, apparatus, or device. More specific examples of the computer-readable medium would include the following: a portable computer diskette, a random access memory (RAM) circuit, a read-only memory (ROM) circuit, an erasable programmable read-only memory (EPROM or Flash memory) circuit, a portable compact disc read-only memory (CD-ROM), and a portable digital video disc read-only memory (DVD/BlueRay).
The computer program instructions may also be loaded onto a computer and/or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer and/or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.
Accordingly, embodiments of the present inventive concept may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.) that runs on a processor such as a digital signal processor, which may collectively be referred to as “circuitry,” “a module” or variants thereof.
It should also be noted that in some alternate implementations, the functions/acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Moreover, the functionality of a given block of the flowcharts and/or block diagrams may be separated into multiple blocks and/or the functionality of two or more blocks of the flowcharts and/or block diagrams may be at least partially integrated. Finally, other blocks may be added/inserted between the blocks that are illustrated. Moreover, although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.
Many different embodiments were disclosed herein, in connection with the following description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process Of making and using them, and shall support claims to any such combination or subcombination.
For purposes of illustration and explanation only, various embodiments of the present inventive concept were described herein in the context of user equipment (e.g., “wireless user terminal(s)”, “wireless communication terminal(s)”, “wireless terminal(s)”, “terminal(s)”, “user terminal(s)”, etc.) that are configured to carry out cellular communications (e.g., cellular voice and/or data communications). It will be understood, however, that the present inventive concept is not limited to such embodiments and may be embodied generally in any wireless communication terminal that is configured to transmit and receive according to one or more RATs. Moreover, “user equipment” is used herein to refer to one or more pieces of user equipment. Acronyms “UE” and “UEs” may be used to designate a single piece of user equipment and multiple pieces of user equipment, respectively.
As used herein, the term “user equipment” includes cellular and/or satellite radiotelephone(s) with or without a multi-line display; Personal Communications System (PCS) terminal(s) that may combine a radiotelephone with data processing, facsimile and/or data communications capabilities; Personal Digital Assistant(s) (PDA) or smart phone(s) that can include a radio frequency transceiver and a pager, Internet/Intranet access, Web browser, organizer, calendar and/or a global positioning system (GPS) receiver; and/or conventional laptop (notebook) and/or palmtop (netbook) computer(s) or other appliance(s), which include a radio frequency transceiver. As used herein, the term “user equipment” also includes any other radiating user device that may have time-varying or fixed geographic coordinates and/or may be portable, transportable, installed in a vehicle (aeronautical, maritime, or land-based) and/or situated and/or configured to operate locally and/or in a distributed fashion over one or more terrestrial and/or extra-terrestrial location(s). Finally, the terms “node” or “base station” includes any fixed, portable and/or transportable device that is configured to communicate with one or more user equipment and a core network, and includes, for example, terrestrial cellular base stations (including microcell, picocell, wireless access point and/or ad hoc communications access points) and satellites, that may be located terrestrially and/or that have a trajectory above the earth at any altitude.
In the drawings and specification, there have been disclosed embodiments of the inventive concept and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the inventive concept being set forth in the following claims.
The present application claims priority from U.S. Provisional Application No. 61/566,145 (Attorney Docket No. 9342-534PR), filed Dec. 2, 2011, the disclosure of which is hereby incorporated herein by reference as if set forth in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61566145 | Dec 2011 | US |
