TWM547661U - System for correcting 3D visual coordinate - Google Patents

Abstract

A system for correcting 3D visual coordinate, comprising: a projection panel; a light-emitting device, emitting a vertical light and a horizontal light onto the projection panel; a photographing device, capturing an image displayed in the projection panel; and an image-correcting device, coupled to the photographing device, establishing a first conversion relationship for the image between a projection coordinate system and a true world coordinate system according to the image captured by the photographing device and obtaining a first image; establishing a second conversion relationship for the first image between the true world coordinate system and a geodetic coordinate system according to the first image; and correcting the image according to the first conversion relationship and the second conversion relationship.

Description

3D visual coordinate correction system

This creation is about a 3D measurement technique, more specifically about a 3D vision coordinate correction system.

With the popularity of 3D cameras, stereo vision technology has been widely used in culture, entertainment and scientific research.

The current 3D camera has two left and right photographic lenses, and some conditions are required when using a 3D camera, for example, the position of the left and right photographic lenses in the 3D camera is fixed, and the left and right photographic lenses in the 3D camera satisfy a certain positional relationship.

Due to the level of craftsmanship, the left and right photographic lenses in 3D cameras are not able to meet the ideal placement position and are often skewed by external forces. In this case, in order to satisfy the use requirements of the 3D camera, it is necessary to correct the captured image to establish an imaging model.

In conventional techniques, a precision calibration plate is often used to make accurate and known movements to correct a 3D camera. However, it is difficult to apply to camera correction with a wide range of surveillance. In addition, precision and moveable calibration plates are expensive and complicated to set up.

Therefore, there is a need for a 3D visual coordinate correction system that is simple and can be used for large-scale monitoring to find the original image and corrected image taken. Correspondence between the likes.

The following creations are merely exemplary and are not meant to be limiting in any way. In addition to the illustrative aspects, embodiments, and features, other aspects, embodiments, and features will be apparent from the accompanying drawings. That is, the following authoring content is provided to introduce concepts, priorities, benefits, and novel and non-obvious technical advantages described herein. Selected, not all, embodiments will be described in further detail below. Therefore, the following creative content is not intended to be essential to the claimed subject matter, and is not intended to be used in the scope of the claimed subject matter.

The present invention proposes a 3D visual coordinate correction system, comprising: a projection board; a linear light emitting device for emitting a vertical light and a horizontal light on the projection board; and a photographing device for capturing the projection board Displaying an image; and an image correcting device coupled to the photographing device for establishing a first conversion relationship between the image in a projection coordinate system and a real world coordinate system according to the image captured by the photographing device And obtaining a first image of the image in the real world coordinate system; establishing a second conversion relationship of the first image to the real world coordinate system and the earth coordinate system according to the first image; and according to the first The conversion relationship and the second conversion relationship described above are corrected in the image.

100‧‧‧3D visual coordinate correction system

110‧‧‧Projection board

120‧‧‧Line light emitting device

130‧‧‧Photographing device

140‧‧‧Image Correction Device

200‧‧‧ device

202‧‧‧ Input device

204‧‧‧Output device

206‧‧‧Control circuit

208‧‧‧Central Processing Unit

210‧‧‧ memory

212‧‧‧ Code

214‧‧‧ transceiver

The drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of the present invention. The drawings illustrate embodiments of the present teachings and together with the description to explain the principles of the present invention. It can be understood that the drawings are not necessarily drawn to scale. In addition, some components may be displayed in excess of the size of the actual implementation to clearly illustrate the concept of the present invention.

1 is a schematic diagram of a 3D visual coordinate correction system according to an embodiment of the present invention.

Figure 2 is a simplified functional block diagram of a device in accordance with an embodiment of the present invention.

3A, 3B, 4A and 4B are diagrams showing the conversion of the projection coordinate system into a real world coordinate system by the image correcting device according to an embodiment of the present invention.

Fig. 5 is a view showing the conversion of a real world coordinate to a geodetic coordinate system by the image correcting device according to an embodiment of the present invention.

6A-6D are schematic diagrams showing the process of converting the vertical light and the horizontal light emitted by the linear light emitting device onto the projection plate from the projection coordinate system to the earth coordinate system according to the image correcting device according to an embodiment of the present invention.

In order to make the objects, features, and advantages of the present invention more comprehensible, the preferred embodiments will be described in detail below with reference to Figures 1 through 6D of the accompanying drawings. This description provides different embodiments to illustrate the technical features of the various embodiments. The configuration of each component in the embodiments is for illustrative purposes and is not intended to limit the present invention. The overlapping portions of the drawings in the embodiments are for the purpose of simplifying the description and are not intended to be related to the different embodiments.

The term "exemplary" is used herein to mean that the disclosed elements or embodiments are merely an example and do not indicate any preference of the user. In addition, the same numerals indicate the same elements in all the figures, and the articles "a" and "an"

It must be understood that the terms "including" and "including" used in the specification are used to indicate that there are specific technical features, numerical values, method steps, process processing, components and/or components, but do not exclude Add more technical features, values, method steps, job processing, components, components, or any combination of the above.

1 is a schematic diagram of a 3D visual coordinate correction system 100 in accordance with an embodiment of the present invention. The 3D visual coordinate correction system 100 can include a projection board 110, a linear light emitting device 120, a photographing device 130, and an image correcting device 140. The projection panel 110 is placed perpendicular to the ground. In one embodiment, the projection panel 110 can also be replaced by a wall or plane perpendicular to the ground.

The linear light emitting device 120 is a device that emits a vertical light and a horizontal light, and the vertical light is an absolute vertical baseline, and the horizontal light is an absolute horizontal baseline. In one embodiment, the linear light emitting device 120 can be a laser light emitting device that emits vertical laser light and a horizontal laser beam. The linear light emitting device 120 is placed in front of the projection plate 110 to emit vertical light and horizontal light onto the projection plate 110.

The photographing device 130 may be any commercially available depth 3D camera capable of capturing 3D images, such as a binocular camera/camera with two lenses, a single camera capable of continuously taking two photos of a camera/camera, a laser stereo camera/camera (Photographing device with laser measurement depth value), infrared stereo camera/camera (photographic device with infrared measurement depth value), and the like. A common deep 3D camera is the Kinect developed by Microsoft. The photographing device 130 is set to be photographed at a high position to capture an image displayed on the projection panel 110. Since the projection board 110 is a two-dimensional plane, the image system captured by the photographing device 130 is For a two-dimensional image.

The image correcting device 140 can be a computer or a mobile device, which can be coupled to the photographing device 130 in a wired or wireless manner to receive the original image transmitted by the photographing device 130. As shown in FIG. 1, the original image may include vertical light and horizontal light projected onto the projection panel 110. The image correcting device 140 is configured to calculate a conversion relationship between the original image captured by the photographing device 130 and the corrected image. The method of calculation will be explained in more detail below.

Figure 2 is a simplified functional block diagram of a device 200 in accordance with an embodiment of the present invention. As shown in FIG. 2, the apparatus 200 may be the image correcting apparatus 140 in the visual coordinate correction system 100 of FIG. 1D. The device 200 can include an input device 202, an output device 204, a control circuit 206, a central processing unit (CPU) 208, a memory 210, a code 212, and a transceiver 214. The control circuit 206 executes the code 212 in the memory 210 through the central processing unit 208, and thereby controls the operations performed in the device 200. The device 200 can utilize the input device 202 (eg, a keyboard, numeric keys, touch screen, or microphone (sound input)) to receive user input signals; the output device 204 (eg, a screen or speaker) can also output images and sounds. The transceiver 214 is here used to receive and transmit wireless signals, send the received signals to the control circuit 206, and wirelessly output the signals generated by the control circuit 206.

3A-4B are diagrams showing the conversion of the projection coordinate system into a real world coordinate system by the image correcting device according to an embodiment of the present invention. As shown in FIG. 3A, the imaging plane of the photographing device is a projection coordinate system in which the unit used is a pixel. Assume that the resolution of the imaging plane is w × h (pixel ² ), and the size of its plane is l _w × l _h mm ² . In addition, the coordinate value of the pixel of the projection coordinate system is converted into a real world coordinate system of unit mm. Since the origin of the projection coordinate system is at the upper left corner of the imaging plane, the origin of the real world coordinate system is at the center of the imaging plane, as shown in Fig. 3B.

Given a pixel coordinate value at ( p _w , p _h )pixel, the size of the origin from the pixel coordinates is ( p _w ×( l _w / w ), p _h ×( l _h / h )) mm. The position of the real world coordinate system is expressed as ( x _v , y _v ) as follows:

Next, it is assumed that the horizontal field of view and the vertical field of view of the photographing device are θ _w and θ _h , respectively, and the focal length of the photographing device is f mm. Then, according to the 4A-4B chart, the following relationship is obtained:

The photographic device provides a depth z _k mm of pixels ( p _w , p _h ). It is worth noting that the depth of the imaging plane is f , which is the focal length of the photographic device. Referring to Figures 4A-4B, Figure 4A is a schematic diagram showing the relationship between the projection coordinate system and the real world coordinate system on the XZ plane, and Figure 4B is a schematic diagram showing the relationship between the projection coordinate system and the real world coordinate system on the YZ plane. Point (x _v, y _v) on the imaging plane of the real object (Physical Object) in the spatial position (x _k, y _k) may be calculated using trigonometry, which is shown in the following equation.

Fig. 5 is a view showing the conversion of a real world coordinate to a geodetic coordinate system by the image correcting device according to an embodiment of the present invention. As shown, the +Y axis (+ Y _k ) of the real world coordinate system is defined as facing the ground, while the +Y axis (+ Y _g ) of the earth coordinate system is defined as facing the sky (anti-gravity direction), two coordinates The origin of the system is set at the center of the photographic device, and both are in the right hand coordinates. In order to obtain true 3D information, the real world coordinate system must be converted to conform to the Earth coordinate system.

Relationship between the two orthogonal coordinate system can be represented by Euler angles: rotation about the Z axis angle ψ, then the new Y-axis coordinate system about the rotor turn angle θ, and finally about the Z axis of the coordinate system of the latest rotation angle φ. The result is the product of three rotation matrices: Rot ( z , ψ) Rot ( y , θ ) Rot ( z , φ). Since the creation of the angle detection computing only the vertical line of the main shaft thereof, and requires a plumb line ground to the sky (anti-gravity direction) of the Y-axis of the ground coordinate system, but not with the X-axis direction, as long as the XZ plane The water level is fine. Therefore, as long as two rotations can rotate the real world coordinate system to the earth coordinate system: the rotation angle around the Z axis, so that the X axis falls on the horizontal plane; then rotate the θ angle around the new X axis, let the Y axis and lead The vertical line is consistent.

This creation defines the geodetic coordinate system as E _G ={g _x ,g _y ,g _z }, and the real world coordinate system of the photographic device is E _K ={k _x ,k _y ,k _z }. Let R _K→G be a coordinate transformation matrix from E _K to E _G , which can be expressed as follows.

If the space represented by the real world coordinate system of the photographing device is ( x _k , y _k , z _k ), and the earth coordinate system is expressed as ( x _g , y _g , z _g ), then Can get Since R _K→G is an orthogonal matrix, ( R _K→G ) ⁻¹ =( R _K→G ) ^T .

6A-6D are schematic diagrams showing the process of converting the vertical light and the horizontal light emitted by the linear light emitting device onto the projection plate from the projection coordinate system to the earth coordinate system according to the image correcting device according to an embodiment of the present invention.

As shown in FIG. 6A, it is a schematic diagram showing vertical light and horizontal light emitted by the linear light emitting device on the projection plate. The photographing device captures the image displayed on the projection board and transmits it to the image correcting device. Figure 6B shows the image captured by the photographic device. As shown, the light projected onto the projection panel is presented as a point cloud. Generally speaking, the light should be presented in a straight line, but the phenomenon that the light is dithered can be observed from the point cloud image. This phenomenon is caused by the resolution of the photographing device.

If the two-point arithmetic vector is taken directly on the dithered ray point cloud image, it is possible that the calculated linear vector has a deviation from the actual ray vector due to the different positions of the selected points. In order to solve this problem, the image correction device of this creation uses Principal Component Analysis (PCA) to establish the conversion relationship between the actual coordinate vector and the real coordinate system, which is taken in the real world coordinate system. The main vector, which represents the vector of two rays. As shown in Fig. 6C, it shows an approximate straight line obtained by the PCA operation of the three-dimensional point of the light.

In the present creation, the calculated first principal component u _{k 1} of the vertical ray in the real world coordinate system, the u _{k 1} vector is approximately the direction of the vertical ray. Let u _{g 1} be the first principal component of the vertical ray obtained in the earth coordinate system. Since the vertical ray is perpendicular to the horizontal plane, the x and z components of the u _{g 1} vector are both zero. Using the above conditions, the relationship between this vector in the real world coordinate system and the earth coordinate system can be expressed as From the above formula, the angle of rotation of the real world coordinate system around the Z axis can be obtained.

The PCA method is performed on the point on the horizontal light, and the first principal component v _{k 1 of the} horizontal light is obtained in the real world coordinate system, and the v _{k 1} vector is approximated to the direction of the horizontal light. Let v _{g 1} be the first principal component of the horizontal ray obtained in the earth coordinate system. Since the horizontal ray in the earth coordinate system is parallel to the horizontal plane, the y component of the v _{g 1} vector is zero. Therefore, the relationship between this vector and the real world coordinate system and the earth coordinate system can be expressed as From the above formula, the coordinate of the coordinate of the coordinate of the real world coordinate system around the Z-axis rotation angle ψ and the Y-axis rotation angle θ is obtained.

After the vertical light and the horizontal light are obtained by the PCA method, the image correcting device redraws the original light with the information of the first main component, and converts the light into the real world coordinate system and the earth coordinate system. The light is as shown in Figure 6D.

In addition, the central processing unit 208 in FIG. 2 can also execute the code 212 to present the actions and steps described in the above embodiments, or other descriptions in the description.

Therefore, through the 3D visual coordinate correction system proposed by the present invention, it is only necessary to use a simple projection board and a linear light emitting device capable of emitting horizontal and vertical light to find the image captured by the 3D camera and the corrected image. The corresponding relationship can also achieve the effect of large-scale monitoring.

The above embodiments are described using a variety of angles. It will be apparent that the teachings herein may be presented in a variety of ways, and that any particular structure or function disclosed in the examples is merely representative. In light of the teachings herein, anyone skilled in the art will appreciate that the content presented herein can be independently rendered in various different types or in a variety of different forms. By way of example, it may be implemented by some means or by some means in any manner as mentioned in the foregoing. The implementation of one device or the execution of one mode may be implemented in any one or more of the types discussed above with any other architecture, or functionality, or architecture and functionality.

Those skilled in the art will understand that messages and signals can be presented in a variety of different technologies and techniques. For example, all of the data, instructions, commands, messages, signals, bits, symbols, and chips that may be referenced above may be volts, current, electromagnetic waves, magnetic or magnetic particles, light fields or light particles, or Any of the above The combination is presented.

Those skilled in the art will appreciate that various illustrative logic blocks, modules, processors, devices, circuits, and logic steps are described herein for use with the electronic hardware (eg, source coded or Digital implementation of other technical designs, analogy implementation, or a combination of both), various forms of programming or design codes linked to instructions (referred to as "software" or "software modules" for convenience in the text), or a combination of the two. To clearly illustrate the interchangeability of the hardware and software, a variety of descriptive elements, blocks, modules, circuits, and steps are generally described above in terms of functionality. Whether this feature is presented in hardware or software, it will depend on the specific application and design constraints imposed on the overall system. The person skilled in the art can implement the described functions in a variety of different ways for each particular application, but the implementation of this decision should not be interpreted as deviating from the scope disclosed herein.

In addition, various illustrative logical blocks, modules, and circuits, and various aspects disclosed herein may be implemented in an integrated circuit (IC), an access terminal, an access point, or an integrated circuit. , access terminal, access point execution. The integrated circuit can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or the like. Programmable logic device, discrete gate or transistor logic, discrete hardware components, electronic components, optical components, mechanical components, or any combination of the above to perform the functions described herein And may execute an execution code or instruction that exists in the integrated circuit, outside the integrated circuit, or both. General purpose processor possible It is a microprocessor, but it could be any conventional processor, controller, microcontroller, or state machine. The processor may be comprised of a combination of computer devices, such as a combination of a digital signal processor (DSP) and a microcomputer, a plurality of sets of microcomputers, a set of at most groups of microcomputers, and a digital signal processor core, or any other similar configuration.

Any specific sequence or layering of the procedures disclosed herein is by way of example only. Based on design preferences, it must be understood that any specific order or hierarchy of steps in the program may be rearranged within the scope of the disclosure. The accompanying claims are intended to be illustrative of a

Although the present invention has been disclosed above by way of example, it is not intended to limit the scope of the present invention. Anyone skilled in the art can make some changes and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this case is This is subject to the definition of the scope of the patent application.

100‧‧‧3D visual coordinate correction system

110‧‧‧Projection board

120‧‧‧Line light emitting device

130‧‧‧Photographing device

140‧‧‧Image Correction Device

Claims (8)

A 3D visual coordinate correction system includes: a projection board; a linear light emitting device for emitting a vertical light and a horizontal light on the projection board; and a photographing device for capturing one of the displayed on the projection board And an image correcting device coupled to the photographing device for establishing a first conversion relationship between the image and a real world coordinate system according to the image captured by the photographing device, and obtaining And the image is in the first image of the real world coordinate system; and the second image is coupled to the first image according to the first image to establish a second conversion relationship between the real world coordinate system and the earth coordinate system; and according to the first conversion relationship and The second conversion relationship corrects the image. The 3D visual coordinate correction system of claim 1, wherein the projection plate is placed perpendicular to the ground. The 3D visual coordinate correction system of claim 1, wherein the image system comprises the vertical light and the horizontal light emitted to the projection plate, and the image correcting device utilizes a principal component analysis (Principal Component Analysis, The PCA) obtains a true vertical vector and a true horizontal vector corresponding to the vertical light and the horizontal light in the real world coordinate system. The 3D visual coordinate correction system according to claim 3, wherein the second vertical relationship between the true vertical vector in the real world coordinate system and the earth coordinate system is among them, Is the above true vertical vector, Is the true vertical vector of the earth in one of the above-mentioned geodetic coordinate systems. For the angle at which the real world coordinate system is rotated about its Z axis, θ is the above real world coordinate system rotating the angle around its Z axis The angle at which it is rotated about its Y axis. The 3D visual coordinate correction system according to claim 3, wherein the second horizontal relationship between the real horizontal vector in the real world coordinate system and the earth coordinate system is among them, Is the above true horizontal vector, Is the true horizontal vector of the earth in one of the above-mentioned geodetic coordinates. For the angle at which the real world coordinate system is rotated about its Z axis, θ is the above real world coordinate system rotating the angle around its Z axis The angle at which it is rotated about its Y axis. A 3D visual coordinate correction system as described in claim 1 of the patent application, The above-mentioned photographing device is a deep 3D camera. The 3D visual coordinate correction system of claim 1, wherein the image correction device is a computer or a mobile device. The 3D visual coordinate correction system according to claim 1, wherein the projection board is replaced by a wall surface.