KR20160073488A - Handheld 3D Scanner - Google Patents

Abstract

The present invention relates to a portable three-dimensional scanner capable of generating texture in real time. The scanner according to the present invention comprises: a laser emitting a laser beam to an object; a video camera generating a video for the object to which the laser beam is emitted; a still camera generating a still image for the object to which the laser beam is emitted; and a processor generating a three-dimensional point information group for the object by analyzing the video frame, obtaining a still image by operating the still camera at predetermined time intervals or each time the accumulation number of analyzed frames exceeds a threshold, and generating a texture coordinate for the generated three-dimensional point information group using the obtained still image.

Description

Handheld 3D Scanner

The present invention relates to a 3D scanner, and more particularly, to a portable 3D scanner capable of real-time texture generation.

Recently, the most popular 3D scanners are laser optics and structural optics. Scanners often use structured optics with high accuracy. Since the fixed type laser optical system is used or the structured light is used, the image scanner can be used as a texture by taking a photograph only once. For example, in the case of a fixed laser optical system (for example, a DAVID scanner), a line is scanned up and down at a fixed position, and an image is taken at a corresponding position to use as a texture of upper and lower lines. EVA Scanner), the area is scanned, so the image is taken at the same time as the area scan and used as the texture of the area corresponding to the area.

On the other hand, in the case of a conventional portable laser line scanner, since it is used for accuracy measurement in a coordinate measuring machine (CMM) field, no texture is needed and no texture is generated.

However, there is a need to create textures to make handheld laser line scanners an affordable 3D scanner.

Therefore, embodiments of the present invention propose a scanner capable of real-time texture generation.

According to an aspect of the present invention, there is provided a scanner comprising: a laser for projecting a laser beam onto a target object; A moving picture camera for generating a moving picture for the object to which the laser beam is projected; A still camera for generating a still image for the object to which the laser beam is projected; And generating a 3D point information set for the object by analyzing the moving picture frame, and activating the still camera every predetermined time interval or every time the cumulative number of frames analyzed exceeds a threshold value, And generating a texture coordinate for the generated 3D point information set using the obtained still image.

According to the embodiment of the present invention, a portable laser line scanner can be utilized as an inexpensive 3D scanner by adding a function of generating a real-time texture to an existing portable laser line scanner.

FIG. 1 is a view schematically showing the configuration and operation of an existing portable laser line scanner.
FIG. 2 is a view schematically showing a configuration and operation of a portable laser line scanner according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating 3D vertices and moving image frames / photographs calculated through the scanner of FIG. 2. FIG.
FIG. 4 is a block diagram showing a more detailed configuration of a scanner according to an embodiment of the present invention.
5 is a flowchart illustrating a process of generating a texture in a portable scanner according to an exemplary embodiment of the present invention.
6 is a conceptual diagram illustrating a 3D information DB according to an embodiment of the present invention.
7 shows a polygon mesh generated as a result of a brief triangulation.
8 illustrates a still image selection function for texture generation of a polygon mesh according to an embodiment of the present invention.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of known related arts will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured.

In addition, the singular phrases used in the present specification and claims should be interpreted generally to mean "one or more " unless otherwise stated.

Also, the terms "module,""part,""interface," and the like, used in the present specification generally mean computer-related objects and may mean, for example, hardware, software and combinations thereof.

FIG. 1 is a view schematically showing the configuration and operation of an existing portable laser line scanner.

As shown in FIG. 1, a conventional laser line scanner (hereinafter referred to as 'scanner') 110 includes a laser 111 and a moving picture camera 112. The scanner 110 illuminates the laser 111 on the object 120 and at the same time captures the object 120 using the moving picture camera 112. When a laser image is formed on the object 120, the corresponding laser line 121 is recorded on each frame of the moving image. At this time, the position of the laser 111 is calibrated using the position and direction of the scanner 110 and the relative position and direction information between the laser 111 and the moving picture camera 112 in the scanner 110, The points of the pixel corresponding to the laser line of the moving picture frame are calculated as 3D points. On the other hand, since filtering such as brightness and exposure is performed so that the laser line can be clearly seen on each frame image of the photographed moving image, it is difficult to use the image as the color or texture of the 3D point.

In order to solve such problems, the present invention proposes a portable scanner equipped with a still camera, which can photograph photographs of an object at predetermined intervals and generate real-time textures using the photographs and camera information.

FIG. 2 is a view schematically showing a configuration and operation of a portable laser line scanner according to an embodiment of the present invention.

The portable laser line scanner (hereinafter, referred to as 'scanner') 210 proposed in the embodiment of the present invention is further provided with a still camera 213 and a flash 214 in the existing laser line scanner described in FIG. A method in which the scanner 210 irradiates the laser 211 to the object 220 and simultaneously photographs the object 220 using the moving image camera 212 is similar to the conventional scanner. However, there is a difference from conventional scanners in that still cameras 213 and flashes 214 are operated to acquire still images (photographs) of the object object 220 as well. FIG. 3 is a diagram illustrating 3D points and moving image frames / still images (photographs) calculated through the scanner of FIG.

FIG. 4 is a block diagram showing a more detailed configuration of a scanner according to an embodiment of the present invention.

As shown, the scanner 400 includes at least some or all of the laser 410, the moving picture camera 420, the still camera 430, the flash 440, the processor 450 and the memory 460 . Also, although not shown in the figure, the scanner 400 may also have a monitor capable of displaying a result of real-time rendering to a user through scanning of an object.

The laser 410 projects a laser beam onto a target object so that a laser image is formed on the target object.

The moving picture camera 420 captures a moving object and obtains moving images of the target object.

The still camera 430 captures a target object under the control of the processor 450 and acquires a still image for the target object. At this time, a flash 440 can be used together to obtain a clearer picture.

The processor 450 controls all operations of the scanner 400. For example, the processor 450 may control the laser 410 to project the laser beam onto a target object, and may also display the moving picture camera 420 and the still camera 430 in order to obtain the projected moving picture and still picture Can be controlled.

The processor 450 analyzes a moving picture frame obtained from the moving picture camera 420 to generate a 3D point information set and stores the generated 3D point information set in the 3D information DB 461 in the memory 460. [ For example, when the moving picture is 45 frames / sec, the processor 450 takes a long time to extract the 3D point. Thus, the frame size of about 25 frames / sec. Can only be processed. Accordingly, the processor 450 operates the still camera 430 / flash 440 every predetermined time interval while analyzing the frame and / or every time the analyzed frame number exceeds the predetermined threshold value, And also stores the obtained still image in the 3D information DB 461. The 3D information DB 461 stores the acquired still image. The 3D information DB 461 may store together with the acquired still image data the camera information including the direction and position information of the camera at the time of shooting the target object.

The still image thus obtained will be used to generate a texture for the 3D point information set.

Specifically, the processor 450 generates a series of polygon meshes using the 3D point information extracted from each of the two or more frames, and generates a series of polygon meshes using the still images adjacent to the frames, To create texture coordinates for the texture. The generated polygon mesh and texture can be rendered in a preview manner when the user is scanning and displayed to the user in real time.

The processor 450 generates a single mesh through surface reconstruction using the 3D point information stored in the 3D information DB 461 when the scanning of the object is completed and displays the normal of each triangle constituting the mesh Norma) Generate the texture using the still image located in the l direction. Finally, a single mesh through the surface reconstruction is a mesh with increased accuracy, which creates a new texture more suitable for a single mesh.

The memory 450 stores programs necessary to control the operation of the scanner 400 (e.g., programs for performing 3D point information generation through polygon mesh and texture generation through motion picture frame analysis executed by the processor 440) And a 3D information DB 461 and a mesh DB 462 for storing 3D information and mesh data calculated according to the operation of the scanner 400, respectively. As an example, memory 450 may include volatile memory such as SRAM, DRAM, SDRAM, and the like, and various non-volatile memories such as ROM, PROM, EPROM, EEPROM,

5 is a flowchart illustrating a process of generating a texture in a portable scanner according to an exemplary embodiment of the present invention.

In step S510, a three-dimensional point information set representing an object is generated by analyzing a moving image frame of a target object obtained in real time through a moving image camera. On the other hand, whenever the number of analyzed frames exceeds a predetermined threshold value at predetermined time intervals and / or during a moving image frame analysis, a still camera for a target object is acquired by operating a still camera / flash.

Here, 3D points extracted from one frame can be represented by points on one curve.

In one embodiment, the 3D point information set generated according to the analysis result of each moving picture frame and the still image (photograph) obtained by the still camera are combined with the camera information (for example, camera direction and position information) Lt; / RTI > As shown in FIG. 6, in addition to storing a series of 3D points generated in each frame and moving picture camera information at the time of capturing a moving picture in the 3D information DB according to a result of moving picture frame analysis, The still images (photographs) obtained by each still camera may be stored together with the still camera information at the time of shooting the corresponding image, together with the 3D information DB image and the still camera information, and stored in the 3D information DB.

Referring again to FIG. 5, in step S520, a series of polygon meshes are generated by performing a brief triangulation on the points generated from each of the analyzed two or more frames. As an example of triangulation, a delaunay triangulation may be used. 7 shows a polygon mesh generated as a result of a brief triangulation.

In step S530, texture coordinates for a series of polygon meshes are generated.

In one embodiment, a texture for the polygon mesh is generated using a still image having a direction closest to the camera position of the corresponding frame and having the direction most similar to the direction of the frame with respect to any one of the two frames used for polygon mesh generation, Create the coordinates. 8 illustrates a still image selection function for texture generation of a polygon mesh according to an embodiment of the present invention. As shown in the figure, the still image having the smallest W is selected to generate texture coordinates of the polygon mesh. Texture generation is performed by back-projecting a vertex of a polygon mesh onto a selected still image and using it as the texture coordinate of the corresponding triangle as a generally known method.

In step S540, when the scanning of the object is completed, a single mesh is generated by performing surface reconstruction using 3D points stored in the 3D information DB. A texture is generated using a still image located in a normal (Norma) direction of each triangle constituting the mesh

In step S550, texture coordinates are generated using a still image located in the direction of the normal (Norma) l of each triangle constituting the single mesh generated in the previous step, and the mesh and the texture coordinates generated in correspondence with the mesh are transmitted to the mesh Save to DB.

Embodiments of the texture generation of the present invention as described above may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination.

Program instructions to be recorded on a computer-readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the computer software arts. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Includes hardware devices specifically configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory, and the like. The above-mentioned medium may also be a transmission medium such as a light or metal wire, wave guide, etc., including a carrier wave for transmitting a signal designating a program command, a data structure and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like.

The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

The embodiments of the present invention have been described above. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (1)

A laser for projecting a laser beam onto a target object;
A moving picture camera for generating a moving picture for the object to which the laser beam is projected;
A still camera for generating a still image for the object to which the laser beam is projected; And
And generating a 3D point information set for the object by analyzing the moving picture frame, and activating the still camera every predetermined time interval or every time the cumulative number of analyzed frames exceeds the threshold value, And generating texture coordinates for the generated 3D point information set using the obtained still image,
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