Three-dimensional image capturing system and method for object

Abstract

A system and method for acquiring a three-dimensional profile of an object. The system includes a camera, a moving device, and a control device. The camera includes a lens module and an image sensor imaging module, and a lateral focus plane of the object corresponding to a relative position of the lens module and the image sensor imaging module. The moving device moves the camera relative to the object along a moving path that is not perpendicular to the lateral focus plane of the object. The control device is electrically connected to the camera and the moving device to control the moving device to move and to control the camera to acquire a plurality of slice images of the object as the camera moves relative to the object along the moving path.

Description

Technical Field

[0001] This invention relates to an object shape image acquisition system and method, and more particularly to an object shape image acquisition system and method that uses multiple slice images obtained from the focusing plane of the object on the moving path to resolve the three-dimensional contour of the object's shape. Background Technology

[0002] For a schematic diagram of a previously known imaging system and an imaging method that uses depth of focus (DFF) to resolve the three-dimensional contour of an object's surface, please refer to [link / reference]. Figures 1 to 3 The known method of depth of focus (DFF) for resolving the three-dimensional contours of an object's surface involves using a photographic device to capture images in a scene. From a series of multiple sliced ​​images obtained by continuously moving the focal plane across the object (a concept from computed tomography), the three-dimensional depth information of the object's shape is resolved by evaluating the changes in focus quality across each image. A typical architecture of previous techniques, such as... Figure 1 As shown, the moving path 80a of the image slice obtained by the photographic device 10a is perpendicular to the focusing plane 0, 1, 2, 3, 4 on the side of the object to be tested. Since there is no horizontal image displacement between slices, the focus evaluation value of the object to be tested in the image is relatively simple and clear.

[0003] like Figure 1As shown, in conventional image acquisition methods, when the size of the object to be measured exceeds the field of view (FOV) of a single camera, multiple measurement FOV regions must be planned to maintain the same resolution. The imaging device 100a then sequentially captures multiple slice images at fixed points in each FOV region along the movement path 80a. While the imaging device 100a moves to the next FOV region, i.e., while moving along the movement path 81a, it remains idle and does not capture images. Consequently, the average frame rate per second of the total image acquisition by the imaging device 100a is far lower than its maximum imaging capacity. This is analogous to driving in a narrow alleyway, where you must stop and start again at each intersection, resulting in a much lower average speed compared to a highway. For example, a photographic device 10a capable of capturing 180 images per second requires capturing a series of 90 slice images per area to image the object under test within each field of view. If the entire area of ​​the object under test is large, it needs to be divided into 100 areas (e.g., 20x5 areas) for image acquisition, requiring a total of 9,000 images (90 images x 100 areas) and 100 planar displacement and stop-and-go procedures. If the field of view needs to switch to the next area, the starting acceleration, deceleration before arrival, and adjustment to a complete stop take 0.5 to 1 second. Therefore, the fastest possible acquisition time for the entire process of capturing 9,000 images is at least 50 seconds at full speed, plus 50 to 100 seconds of movement time. The total time for one detection cycle is as long as 100 to 150 seconds. The camera actually only achieves 1 / 2 to 1 / 3 of the highest imaging efficiency of the photographic device (18,000 images @ 100 seconds ~ 27,000 images @ 150 seconds), resulting in low utilization and significant room for improvement.

[0004] The conventional technique of depth-focused (DFF) measurement of object surface profile is described in detail below for ease of understanding. Figure 2 and Figure 3 Only five slice images (0a, 1a, 2a, 3a, and 4a) of the top vertex 91f of the object under test 90f are plotted, because the same photographic device 10a has a fixed focal length. Figure 2 and Figure 3 It can be seen that the top vertex 91f is only clearly visible in slice image 2a. In slice images 0a, 1a, 3a, and 4a, the top vertex 91f is a slightly out-of-focus to severely out-of-focus blurry image. The depth of focus (DFF) is determined by analyzing the changes in the image characteristics of the object from blurry to clear to blurry, and then resolving the slice index number (i.e., the relative height of the top vertex 91f) of the image where the outline of the object under test is clearly focused. In this example of five slice image sequences, slice image 91f with index number 2a is the clearest.

[0005] The most common method for evaluating object sharpness in scene images is to use a Laplace filter to assess the gradient of grayscale values ​​between adjacent feature points. This is a gradient function convolution operation that calculates the grayscale gradient change at each pixel location, i.e., convolving each pixel's grayscale with its surrounding pixels.

[0006]

[0007] The kernel As shown in Table 1 below:

[0008]

[0009] Table 1. Example of meta-parameters for 3x3 convolution operation of gradient function (@ Convolution range values ​​a and b are both 1)

[0010] If there are noise concerns in the sliced ​​images acquired by the imaging device 100a, a smoothing filter (such as a Gaussian filter) can be used first, followed by a Laplace operation. The smoothing filter and the Laplace filter can be combined into a single filter (LoG) to save computing power. Details of the Gaussian filter will not be elaborated here.

[0011] The convolution values ​​of the same pixel in each slice are aggregated to form a one-dimensional array of image sharpness evaluation intensity values. The slice index number containing the maximum evaluation value is searched within this one-dimensional array and recorded. To obtain more accurate depth resolution, trend interpolation can be performed on the focus evaluation values ​​of the preceding and following slice images to obtain a higher-precision floating-point index number. In conventional technical practice, DFF detection applications mostly involve narrow-angle field-of-view equivalent long focal length imaging. When the camera or the object under test is moved relative to the fixed focal length plane, there is a slight magnification variation between the out-of-focus imaging on the non-focus plane and the focused imaging on the focus plane. However, this does not affect the one-dimensional array focus layer index resolution of each pixel region (e.g., 3x3, 5x5). Using a telecentric lens (virtual super telephoto) design can achieve higher accuracy, but the lens cost is significantly higher.

[0012] The matrix of slice index records for all pixels represents the relative depth of the three-dimensional shape of the object's surface in the image coordinate system. Furthermore, the distance between adjacent slice layers on the object-side focusing plane of the photographic apparatus 100a (the distance between adjacent layers 0, 1, 2, 3, and 4 of the focusing plane) is the unit constant for the transformation from the image pixel coordinate system to the real-world coordinate system. From this, the final three-dimensional depth map of the object in the real world can be obtained.

[0013] The depth-of-focus (DFF) measurement system can acquire images by moving the camera 100a along the Z-axis on a transfer platform (not shown) that carries the camera 100a, or by moving the object platform to be measured along the Z-axis. It should be noted that the Z-axis direction here refers to the vertical direction. Both relative movement imaging methods can utilize a series of slice images obtained by focusing on different positions (relative depth) of the object before and after measurement.

[0014] Recently, while some optical lenses have incorporated variable-curvature liquid lenses or adopted DLP (DMD) reflective lenses to implement electronic analog focusing ring functions, eliminating the need to move the camera device 100a or the object under test 90f, and while images obtained using liquid lenses or DLP (DMD) reflective lenses offer the advantage of low vibration, the non-linear relationship between the lens object distance (p) and image distance (q) due to the hyperbolic nature of the lens (1 / p + 1 / q = 1 / f) results in significant variations in the resolution accuracy of image acquisition distance control. Furthermore, the need for magnification correction during image acquisition at progressively higher magnification levels (compared to that described in paragraph 0007) increases the complexity of subsequent image processing. Moreover, it still requires a fixed point (horizontally stationary) and multiple slice images along the vertical direction (Z-axis), making it impossible to escape the low uptime issue described in paragraph 0003. Summary of the Invention

[0015] The main objective of this invention is to provide an object shape image acquisition system that uses sliced ​​images obtained from multiple focusing planes of the object under test that are tilted (not parallel) to the moving path of the photographic device to analyze the three-dimensional contour of the object under test.

[0016] The main objective of this invention is to provide a method for capturing object shape images by resolving slice images obtained from multiple focusing planes on the object side that are tilted (not parallel) to the moving path of the photographic device to extract the three-dimensional contour of the object shape.

[0017] To achieve the above objectives, the object shape image acquisition system and method of the present invention analyzes the three-dimensional contour of the object under test by evaluating the focus quality changes of slice images obtained from multiple object-side focusing planes tilted relative to the moving path of the photographic device. The system includes a photographic device, a moving device, and a control device. The photographic device includes a lens module and an image sensor imaging module, and an object-side focusing plane corresponding to the relative positions of the lens module and the image sensor imaging module. The moving device allows the photographic device to move relative to the object under test along a moving path, which is not perpendicular to the object-side focusing plane. The control device is electrically connected to the photographic device and the moving device to control the movement of the moving device and, while the photographic device moves relative to the object under test along the moving path, controls the photographic device to acquire multiple slice images of the object under test.

[0018] This invention utilizes the characteristic that the moving path of the imaging device is not perpendicular to the focusing plane of the object under test. The imaging device of this invention only needs to continuously acquire images during lateral movement (e.g., along the X-axis of the platform carrying the imaging device, or along the path interleaving on the XZ plane of the platform carrying the imaging device), allowing the imaging rate of the imaging device to approach the maximum detection imaging rate. Taking the example mentioned in paragraph 0003 of the prior art, this invention only requires approximately 51 to 52 seconds (including forward and backward acceleration and deceleration buffers) for image acquisition and 2.5 to 5 seconds of idle time during column repositioning (e.g., along the Y-axis), for a total time of less than 57 seconds. This is only about 40% to 50% of the detection cycle time of the prior art, equivalent to increasing the online detection capability of the production line by 2 to 2.5 times or more, and improving the image acquisition utilization rate of the imaging device. This solves the shortcomings of the prior art, where the imaging device is idle and does not acquire images during movement across multiple fields of view, resulting in low image acquisition utilization and detection capability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a prior art imaging system;

[0020] Figure 2 This is a schematic diagram of a prior art imaging system acquiring a slice image;

[0021] Figure 3 This is a schematic diagram of the selection of the slice image index sequence number in the previous focused analysis technique;

[0022] Figure 4A This is a top view of the object shape image capturing system of the present invention;

[0023] Figure 4B This is a block diagram of the image processing module of the object shape image capturing system of the present invention;

[0024] Figure 5A This is a side view of the object shape image capturing system of the present invention, which uses the lens module of the third embodiment to move and capture images along the moving path of the first embodiment.

[0025] Figure 5B A schematic diagram of pixel offset superposition processing of sliced ​​images according to the present invention;

[0026] Figure 6 This is a schematic diagram of a first embodiment of a lens module applicable to the object shape image capturing system of the present invention;

[0027] Figure 7 This is an application description of the first embodiment of the lens module of the present invention based on the Schiemfrug principle;

[0028] Figure 8 This is a schematic diagram of a second embodiment of the lens module of the object shape image capturing system applicable to the present invention;

[0029] Figure 9 This is a schematic diagram of a third embodiment of the lens module of the object shape image capturing system applicable to the present invention;

[0030] Figure 10 This is a side view of the object shape image capturing system of the present invention, which uses the lens module of the second embodiment to move and capture images along the moving path of the second embodiment.

[0031] Figure 11 This is a flowchart of the first embodiment of the object shape image capturing method of the present invention;

[0032] Figure 12 This is a schematic diagram of pixel offset superposition processing performed on the sliced ​​image obtained by the lens module of the second embodiment of the present invention.

[0033] Figure 13A and Figure 13B A schematic diagram of the image to be evaluated generated by performing pixel offset overlay processing on the sliced ​​image;

[0034] Figure 14A and Figure 14B This diagram shows a sliced ​​image obtained using the lens module of the second embodiment of the present invention, which is a three-dimensional depth map of the object image coordinate system with the normal of the focusing plane of the object side as the reference coordinate and the three-dimensional depth map of the world coordinate system with the normal of the first plane as the reference.

[0035] Figure 15 This is a flowchart of a second embodiment of the object shape image capturing method of the present invention;

[0036] Figure 16 This is a schematic diagram of the focal plane corresponding to the trapezoidal distortion correction of the image sensor image;

[0037] Figure 17 This is a flowchart of the third embodiment of the object shape image capturing method of the present invention;

[0038] Figure 18 This is a schematic diagram of the image focusing of an object point on the focusing surface of the lens module of the third embodiment of the present invention, which corresponds to the image sensor, from blurry to clear and then back to blurry.

[0039] Figure 19 This is a schematic diagram of pixel offset superposition processing performed on the sliced ​​image obtained by the lens module of the third embodiment of the present invention.

[0040] Figures 20 to 22 This is a schematic diagram showing how the sliced ​​image obtained by the lens module of the third embodiment of the present invention is finally converted into a world coordinate system image after being processed by the object shape image capturing method of the present invention.

[0041] [Symbol Explanation]

[0042] Object shape image acquisition system 1, 1a

[0043] Photographic devices 10, 10a, 10b, 100a

[0044] Lens modules 11, 11a, 11b

[0045] Lens optical center axis 111

[0046] Lens focal point 112

[0047] Image sensor imaging plane normal 131

[0048] Image sensor imaging module 13

[0049] 3D Depth Map in World Coordinate System (300)

[0050] Object side focal plane normal 151

[0051] Perceptor deviation angle 17

[0052] Lens deviation angle 18

[0053] Focusing plane deviation angle 19

[0054] Mobile device 20

[0055] Reference planes 35 and 35a of the test platform

[0056] Test platform 30, 30a

[0057] Control device 50

[0058] Image processing module 60

[0059] Evaluation Module 61

[0060] Image spatial conversion module 62

[0061] Matrix Transformation Module 63

[0062] First plane 70

[0063] First plane normal 71

[0064] Object points 92c, 92d, 92e

[0065] Top vertex 91f

[0066] First axis transfer guide rail 21

[0067] Second axis transfer guide rail 22

[0068] Movement paths 80, 80a, 81a, 80b, 80c

[0069] Third axis transfer guide rail 23

[0070] Test samples 90, 90a, 90b, 90c, 90d, 90e, 90f

[0071] Image Center Reference Point 817

[0072] Image interval distance 890

[0073] Layer spacing thickness 880

[0074] 700 images to be evaluated

[0075] Visible range 31

[0076] Unit image capture range 33

[0077] Pixel offsets T and T'

[0078] Center points 16a, 16b, 16c, 16d, 16e

[0079] Image coordinate system 3D depth map 710

[0080] Location pixels A, B, C, D, a, b, c, d

[0081] Mirror surface 14

[0082] Schiemfrug paid a total of 90

[0083] The focusing planes on the side of the object under test are 15a, 15b, 15c, 15d, 15e, 0, 1, 2, 3, 4.

[0084] Sliced ​​images 800a, 800b, 800c, 800d, 800e, 0a, 1a, 2a, 3a, 4a

[0085] Post-alignment slice images 800a', 800b', 800c', 800d', 800e'

[0086] Trapezoidal / rectangular correction of projected slice images 800a*, 800b*, 800c*, 800d*, 800e*

[0087] Contour feature point images 820, 820a, 820b, 820c, 820d, 820e

[0088] Contour feature point images 830, 830a, 830b, 830c, 830d, 830e

[0089] Contour feature point images 840, 840a, 840b, 840c, 840d, 840e Detailed Implementation

[0090] To better understand the technical content of this invention, preferred embodiments are described below. Please refer to the following description as well. Figure 4A , Figure 5A and Figure 5B The diagram includes a top view of the object shape image capturing system of the present invention, a side view of the object shape image capturing system of the present invention using the lens module of the third embodiment to move and capture images along the first embodiment of the moving path, and a diagram of pixel offset superposition processing of the sliced ​​image.

[0091] like Figure 4A and Figure 5A As shown, in the first embodiment of the present invention, the object shape image acquisition system 1 of the present invention is used to find the shape contour 91 of an object 90 under test 90 by evaluating the focus quality changes of multiple slice images obtained from the object-side focus plane tilted in the moving direction of the photographic device. The object 90 under test 90 can be a circuit board, motherboard, surface mount device, such as IC chip, resistor, capacitor, inductor, bare die, and wafer. In this embodiment, the object shape image acquisition system 1 of the present invention includes a photographic device 10, a moving device 20, an object-side platform 30, and a control device 50. The photographic device 10 includes a lens module 11 and an image sensor imaging module 13, wherein the relative positions of the lens module 11 and the image sensor imaging module 13 correspond to the object-side focus plane 15, which can be basically regarded as the image-clear slice plane of the photographic device 10. According to a specific embodiment of the present invention, the relative positions of the lens module 11 and the image sensor imaging module 13 are determined by the corresponding object-side focusing plane 15 according to the Scheimpflug Intersection Principle, but the present invention is not limited to this embodiment.

[0092] The moving device 20 moves the imaging device 10 relative to the object 90 along a moving path 80, wherein the moving path 80 of the moving device 20 is not perpendicular to the focusing plane 15 on the object side. The control device 50 is electrically connected to the imaging device 10 and the moving device 20. The control device 50 controls the movement of the moving device 20, and while the imaging device 10 moves relative to the object 90 along the moving path 80, it controls the imaging device 10 to acquire slice images of the object 90 at the focusing planes 15c, 15d, and 15e, respectively, thus forming multiple slice images as referred to in this invention. It should be noted that, as Figure 5AAs shown, in this embodiment, the photographic device 10 moves along the moving path 80 relative to the object to be tested 90 on the first plane 70. The first plane 70 in this embodiment is parallel to the reference plane 35 of the object to be tested platform 30, which is... Figure 5A The XY plane in the diagram. It should be noted here that, as... Figure 5A and Figure 5B As shown, the object-side focusing plane 15 has a focusing surface normal 151. The straight-line distance (along the direction of the focusing surface normal 151) between adjacent object-side focusing planes 15c, 15d, and 15e is defined as the slice interval thickness 880. The moving distance of the photographic device 10 from the object-side focusing plane 15c along the path 80 direction to the next object-side focusing plane (e.g., from the object-side focusing plane 15d to the object-side focusing plane 15e) in the first plane 70 is defined as the image acquisition interval distance 890.

[0093] According to a specific embodiment of the present invention, the imaging device 10 has an image capture frequency of 1 to 1000 frames per second. The lens module 11 may be a lens composed of one or more optical lenses, such as a microscope lens, a shallow depth-of-field large aperture lens, or a telecentric lens with an ultra-long equivalent focal length (EFL). The image sensor imaging module 13 may be a photocoupled device (CCD), a complementary metal-oxide-semiconductor (CMOS) element, or an indium gallium arsenide (InGaAs) element. The object-side focusing plane 15 is determined according to the Schiemfrug principle, by the relative angle between the lens module 11 and the image sensor imaging module 13 actually used in the imaging device 10. Figure 6 The sensor deviation angle shown is 17 (φ).

[0094] like Figure 4A and Figure 5AAs shown, the object under test 90 is placed on the object under test platform 30, and the object under test platform 30 forms an object under test platform reference plane 35. The object under test platform 30 can be divided into multiple camera field of view (FOV) 31 so that the imaging device 10 can obtain sliced ​​images of the object under test 90. In this embodiment, the moving device 20 includes a first axis transfer guide 21, a second axis transfer guide 22, a third axis transfer guide 23, and a driver (not shown) disposed on each transfer axis, thereby allowing the appropriate height measurement range of the imaging device 10 to be adjusted according to the needs of different applications. In this embodiment, the first axis transfer guide 21 is the X-axis transfer guide, the second axis transfer guide 22 is the Y-axis transfer guide, and the third axis transfer guide 23 is the Z-axis transfer guide. The third axis transfer guide 23 can move along the first axis transfer guide 21 and the second axis transfer guide 22, allowing the imaging device 10 to perform various combinations of oblique linear movements (XZ, XY, YZ, XYZ) in space and plane, moving up, down, left, right, forward, and backward above the stage 30. In this embodiment, the imaging device 10 is positioned on the third axis transfer guide 23. Through the first axis transfer guide 21, the second axis transfer guide 22, and the third axis transfer guide 23, the imaging device 10 forms the full-area imaging range of the object platform 35 as shown in Figure 4. In this embodiment, the control device 50 is a controller, processor, or control software located in an electronic device (such as a computer or a programmable logic controller (PLC)).

[0095] It should be noted that the first plane 70 has a first plane normal 71. When the first plane 70 is an XY plane, the first plane normal 71 is the Z-axis, and the imaging device 10 takes an image along the moving path 80 in the XY plane, the third axis transfer guide 23 (Z-axis) does not need to move perpendicularly relative to the first axis transfer guide 21 (X-axis). That is, the third axis transfer guide 23 carrying the imaging device 10 only needs to move horizontally relative to the first axis transfer guide 21 (e.g., ...). Figure 4A , Figure 5A Moving the image left or right (as shown) completes the sequence image acquisition. Figure 4A , Figure 5A and Figure 5B As shown, during the movement of the imaging device 10 along the moving path 80, the imaging device 10 is actually in different positions (displacement interval distance 890). Therefore, during the continuous movement and image acquisition process of the imaging device 10, the imaging device 10 acquires slice images of the corresponding object-side focusing planes 15c, 15d, and 15e at each image acquisition position. These slice images acquired by the imaging device 10 can provide images of the object 90 from blurry to clear and then back to blurry, for subsequent analysis of the three-dimensional outline of the object 90.

[0096] Furthermore, according to a specific embodiment of the present invention, such as Figure 5A As shown, the normal 151 of the focusing plane 15 on the object-side is perpendicular to the normal 71 of the first plane. The normal 151 forms a focusing plane deviation angle 19(ω) with the normal 71 of the first plane. The focusing plane deviation angle 19(ω) ranges from 0.1 degrees to 60 degrees, 1 degree to 10 degrees, 0.5 degrees to 20 degrees, or 0.1 degrees to 45 degrees. Figure 5A As shown, because the focusing plane 15 on the side of the object under test is not parallel to the first plane 70, the sliced ​​image obtained by the photographic device 10 continuously capturing images along the moving path 80 on the first plane 70 is actually a slanted slice. This slanted sliced ​​image can present more of the external contour features of the side of the object under test 90. Furthermore, one advantage of the present invention having a focusing plane deviation angle 19(ω) is that the focusing plane deviation angle 19(ω) of the present invention can be adjusted according to the different depth measurement range requirements of the object under test 90. For example, when the object under test 90 is a circuit board, a motherboard, or a surface-mounted component with a high component height, the focusing plane deviation angle 19(ω) can be increased, such as 25 degrees, 45 degrees, 60 degrees, etc., to obtain a clearer and more detailed contour of the side of the object under test 90. When the device under test 90 is a low-height component such as an IC chip, resistor, capacitor, inductor, bare die, or wafer, the focusing plane deviation angle 19 (ω) can be reduced, such as by 1 degree, 5 degrees, or 10 degrees, to obtain measurement information on the internal depth of the hole with a larger height-to-depth ratio in the device under test 90.

[0097] Taking the SONY CMOS IMX535, 4Kx3K, H x V 11.2mm x 8.2mm, 12 million pixels, 2.74um pixel size image sensor imaging module 13 as an example, if the object shape image capturing system 1 of the present invention is used in optical inspection systems such as surface mount technology (SMT / SMD) production lines, since the measurement height range of the object under test in such systems is relatively wide, according to trigonometric geometry, if the focal plane deviation angle 19 (ω) is 30 degrees, and the optical magnification of the photographic device 10 is 0.5X, the measurement height range can be approximately 11.2mm (Sin30° / 0.5X=1). If the object shape image capturing system 1 of the present invention is used in a wafer surface optical inspection system, since the object measurement height range of such production lines is relatively narrow, and the focal plane deviation angle 19 (ω) is 2.56 degrees, and with the optical magnification of the photographic device 10 of 5X (e.g., a microscope objective lens), a height measurement range of approximately 100 μm can be obtained. This provides a flexible adjustable measurement height range of approximately 1120 times.

[0098] Please continue to refer to the following. Figure 4A and Figure 5A and refer to them together. Figure 6 and Figure 7A schematic diagram of a first embodiment of a lens module applicable to the present invention and an explanation of the application of the Schiemfrug principle in this embodiment.

[0099] like Figure 6 As shown, in the first embodiment of the lens module 11, the moving path 80 refers to the path along which the photographic device 10 moves horizontally (X-axis) parallel to the first plane 70 (XY plane) formed by the first axis transfer guide 21 (X-axis) and the second axis transfer guide 22 (Y-axis). In this embodiment, the lens optical center axis 111 formed by the lens module 11 moves perpendicularly to the moving path 80. The angle range of the angle 17 (φ) between the normal 131 of the image sensor imaging plane formed by the image sensor imaging module 13 and the sensor deviation angle formed by the lens optical center axis 111 is 0.1 degrees to 60 degrees. When the photographic device 10 moves along the moving path 80 on the first plane 70, the images formed by the image sensor imaging module 13 on the object-side focusing planes 15a, 15b, 15c, 15d, and 15e are respectively... Figure 6 The slice images shown are 800a, 800b, 800c, 800d, and 800e, and their tilted focal plane angles are as follows: Figure 7 The correspondence is determined according to the Schiemfrug principle. It should be noted that the sensor deviation angle 17(φ) of this invention can be adjusted accordingly depending on the shape and size of the object 90 being measured in practical applications. When the object 90 is a circuit board, motherboard, or a surface-mounted component with a large height measurement range, the sensor deviation angle 17(φ) can be increased (e.g., 25°, 45°, 60°, etc.). When the object 90 is an IC chip, resistor, capacitor, inductor, bare die, or wafer, or a component with a small height measurement range, the sensor deviation angle 17(φ) can be decreased to 1 degree, 5 degrees, 10 degrees, etc., suitable for measuring micron-level high-resolution three-dimensional shapes and hole bottom depths.

[0100] Please continue to refer to the following. Figure 4A and Figure 5A and refer to them together. Figure 8 A schematic diagram of a second embodiment of the lens module applicable to the present invention.

[0101] like Figure 8As shown, in the second embodiment of the lens module 11, the moving path 80 refers to the path along which the photographic device 10 moves horizontally (X-axis) on the first plane 70 (XY plane). In this embodiment, the lens module 11a forms a lens optical center axis 111 that is not perpendicular to the moving path 80, and the image sensor imaging module 13 is perpendicular to the lens optical center axis 111; that is, the normal 131 of the image sensor imaging plane of the image sensor imaging module 13 is parallel to the lens optical center axis 111. Furthermore, the lens deviation angle 18(θ) formed by the lens optical center axis 111 and the moving path 80 in this embodiment ranges from 0.1 degrees to 60 degrees. It should be noted that the photographic device lens 11a in this embodiment is a commonly used optical lens module. Because the optical center axis 111 of the lens is not perpendicular to the moving path 80, when the lens module 11a moves along the moving path 80 on the first plane 70, the images formed by the object-side focusing planes 15a, 15b, 15c, 15d, and 15e on the image sensor imaging module 13 are respectively... Figure 8 The sliced ​​images shown are 800a, 800b, 800c, 800d, and 800e. It should be noted that the lens deviation angle 18(θ) formed by the lens optical center axis 111 and the moving path 80 in this embodiment can be adjusted accordingly depending on the shape and size of the object under test 90. In application, when the object under test 90 is a circuit board, motherboard, or a surface-mounted component with a high component height, the lens deviation angle 18(θ) can be increased (e.g., 25°, 45°, 60°, etc.), and the contour measurement of the side of the object under test 90 can be obtained (which cannot be achieved by the conventional DFF method where the lens center line is vertically up and down along the Z-axis). When the object under test 90 is an IC chip, resistor, capacitor, inductor, bare die, or wafer, etc., with a small height measurement range, the lens deviation angle 18 (θ) can be adjusted to 1 degree, 5 degrees, 10 degrees, etc., and can measure the side of the object's appearance or the depth ratio of 57.3:1 and the inner wall of the hole (@1°Tilt).

[0102] Please continue to refer to the following. Figure 4A and Figure 5A and refer to them together. Figure 9 A schematic diagram of a third embodiment of the lens module applicable to the present invention.

[0103] like Figure 9As shown, in the third embodiment of the lens module 11, the moving path 80 refers to the path along the horizontal (X-axis) of the photographic device 10 on the first plane 70 (XY plane). In this embodiment, the lens optical center axis 111 formed by the lens module 11b is not perpendicular to the moving path 80, and the image sensor imaging plane 13 is parallel to the moving path 80, i.e., the sensor deviation angle 17 (φ) is equal to the lens deviation angle 18 (θ), where the angles φ and θ both range from 0.1 degrees to 60 degrees. When the camera module 10b moves along the moving path 80 on the first plane 70, the images formed by the object-side focusing planes 15a, 15b, 15c, 15d, and 15e on the image sensor imaging module 13 are... Figure 9 The slice images shown are 800a, 800b, 800c, 800d, and 800e. It should be noted that in this embodiment, the sensor deviation angle 17 (φ) and lens deviation angle 18 (θ) can be adjusted according to different objects under test 90. In practical applications, when the object under test 90 is a circuit board, motherboard, or a surface-mounted component with a high component height, the sensor deviation angle 17 (φ) and lens deviation angle 18 (θ) can be increased, such as φ and θ being 25 degrees, 45 degrees, 60 degrees, etc., thereby obtaining a clearer and more detailed outline of the side of the object under test 90. When the object under test 90 is a low-height component such as an IC chip, resistor, capacitor, inductor, bare die, or wafer, the sensor deviation angle 17 (φ) and lens deviation angle 18 (θ) can be reduced, such as φ and θ being 1 degree, 5 degrees, 10 degrees, etc., so that the measurable depth ratio is 57:1 or greater and deeper (similar to the lens module 11a of the second embodiment).

[0104] Please continue to refer to the following. Figure 4A and Figure 5A and refer to them together. Figure 10 A side view of the object shape image capturing system of the present invention, which uses the lens module of the second embodiment to move and capture images along the moving path.

[0105] like Figure 4A , Figure 5A and Figure 10As shown, the difference between the second embodiment of the moving paths 80b and 80c and the first embodiment of the moving path 80 is that when the photographic device 10 takes an image along the second embodiment of the moving paths 80b and 80c, while the third axis transfer guide rail 23 (Z-axis) moves horizontally (left and right) relative to the first axis transfer guide rail 21 (X-axis), the third axis transfer guide rail 23 also moves vertically relative to the first axis transfer guide rail 21, so that the third axis transfer guide rail 23 carrying the photographic device 10 moves obliquely (obliquely upward, obliquely downward) relative to the first axis transfer guide rail 21. That is, the moving path 80 in this embodiment has an upward path (shown in moving path 80c) and a downward path (shown in moving path 80b). At this time, the first plane 70a is the moving inclined plane (XZ) of the photographic device 10 formed by the photographic device 10 on the first axis transfer guide rail 21 and the third axis transfer guide rail 23. Specifically, with Figure 10 As shown in the side view, the normal 131 of the image sensor of the photographic device 10b is parallel to the optical central axis 111 of the lens, and the normal 131 of the image sensor's imaging plane and the optical central axis 111 of the lens are perpendicular to the reference plane 35 of the object platform. Meanwhile, in Figure 10 From the perspective shown, the photographic device 10b, viewed as a whole, forms a path resembling the letter V (V, VV, VVV…) consisting of continuous repeating movement paths 80b and 80c on the XZ plane perpendicular to the first axis transfer guide 21. The first axis transfer guide 21 and the third axis transfer guide 23 move in tandem, forming a straight, oblique path (+XZ, +X+Z). It should be noted that the focusing planes 15a, 15b, 15c, 15d, 15e, 15f, 15g, 15h, and 15i on the object side, which mate with the movement paths 80b and 80c, are parallel to the reference plane 35 of the object platform. Furthermore, the object shape image acquisition system 1 of this embodiment uses… Figure 8 The photographic device 10a shown is a lens module 11a in which the normal 131 of the image sensor imaging plane is parallel to the optical center axis 111 of the lens. This lens module 11a is a common existing optical lens module.

[0106] like Figure 10 As shown, in this embodiment, because the focusing plane 15 on the object under test side is parallel to the reference plane 35 of the object under test platform (similar to the conventional DFF imaging focusing plane), therefore, in such an embodiment... Figure 10In the embodiment shown, where the first axis transfer guide 21 and the third axis transfer guide 23 move in tandem along the inclined straight lines (+XZ, +X+Z) on the moving paths 80b and 80c, when the photographic device 10a moves along the moving path 80b toward the object under test 90, the photographic device 10a first sequentially acquires slice images of the focusing planes 15a, 15c, 15e, 15g, and 15i on the side of the object under test. When the photographic device 10a moves along the moving path 80c toward the direction away from the object under test 90, the photographic device 10a then sequentially acquires slice images of the focusing planes 15h, 15f, 15d, and 15b on the side of the object under test. In other words, according to a specific embodiment of the present invention, when the moving paths 80b and 80c on the first plane 70a are not parallel to the first axis transfer guide rail 21, the respective image slice interval thickness 880 of the photographic device 10a along the moving paths 80b and 80c is such that, since the V-shaped image path interval images of the moving paths 80b and 80c are interleaved and combined, the actual slice interval thickness of the photographic device 10a in the overall image acquisition of the moving paths 80b and 80c becomes half of the slice interval thickness 880, and the slice resolution of the photographic device 10a in the overall image acquisition of the moving paths 80b and 80c is increased by two times.

[0107] For example, such as Figure 10 As shown, when the photographic device 10a moves along the moving paths 80b and 80c to capture images on the first plane 70a, the photographic device 10a captures images at intervals along the moving paths 80b and 80c (e.g., capturing layers with index numbers 1, 3, and 5 on the moving path 80b, and then capturing layers 2, 4, and 6 on the moving path 80c). Then, the original 8-column arrangement is re-overlaid (according to the order of index numbers 1, 2, 3, 4, 5, and 6). The depth range of the photographic device 10a along the moving paths 80b and 80c in this embodiment is determined by the working distance specification of the lens, similar to conventional techniques. Furthermore, in this embodiment, the paths 80b and 80c are formed by the hypotenuse of a right triangle created by the horizontal field of view half-width of the photographic device 10a and the depth of the Z-axis moving slice.

[0108] Furthermore, when the imaging device 10a changes from the moving path 80b (upward path) to the moving path 80c (downward path), or from the moving path 80c (downward path) to the moving path 80b (upward path), the imaging device 10a needs to be offset by half a slice interval thickness 880 at the start of the moving path 80b or moving path 80c, so that the slice images of the imaging series of moving paths 80b and 80c can be staggered and superimposed for subsequent focusing analysis. However, the present invention is not limited to the foregoing embodiments, such as... Figure 10As shown, if the photographic device 10a has m unit imaging ranges 31 along the moving direction, and the photographic device 10a moves in a V-shaped path (moving paths 80b, 80c), when the photographic device 10a completes one V-shaped path, that is, after the photographic device 10a completes one upward path (moving path 80b) and one upward path (moving path 80c), the photographic device 10a moves from the nth unit imaging range 31 to the (n+1)th unit imaging range 31, the present invention applies, where n and m are natural numbers, and m > n.

[0109] Please refer to the following: Figure 4A , Figure 5A , Figure 5B , Figures 6 to 10 and refer to them together. Figure 4B A block diagram of the image processing module of the object shape image capturing system of the present invention.

[0110] like Figure 4A and Figure 4B As shown, the object shape image acquisition system 1 of the present invention further includes an image processing module 60. The image processing module 60 is signal-connected to the control device 50 to receive multiple slice images 800. The image processing module 60 includes an evaluation module 61, an image space conversion module 62, and a matrix conversion module 63. If the photographic device 10 moves along the moving path 80 relative to the object under test 90 at a magnification and acquires multiple slice images 800 of the object under test 90, and the spacing between adjacent slice images 800 has an image acquisition interval distance 890, the image processing module 60 performs a pixel offset superposition processing on the multiple slice images 800 according to a combination of parameters such as magnification, image acquisition interval distance 890, and focus plane deviation angle 19 to generate multiple images to be evaluated. The evaluation module 61 uses a Laplace filter focus evaluation operation program of depth of focus (DFF) to evaluate the focus quality of the multiple images to be evaluated, so as to complete a three-dimensional depth map 710 of the image coordinate system with the focus plane normal 151 of the object under test as the reference coordinate. The image space conversion module 62 converts the object image coordinate system three-dimensional depth map 710, which is based on the normal 151 of the focusing plane of the object to be measured, into a world coordinate system three-dimensional depth map 300 based on the normal 71 of the first plane, according to the focusing plane deviation angle and the image acquisition interval distance.

[0111] It should be noted that, because the image sensor imaging module 13 of the lens module 11 in the first embodiment is not parallel to the focusing plane 15 on the object side, for the lens module 11 of the first embodiment of this invention, before the image processing module 60 performs the pixel offset superposition processing on each of the plurality of sliced ​​images 800, the matrix transformation module 63 performs a geometric deformation matrix transformation on each of the plurality of sliced ​​images 800. For the lens module 11b of the third embodiment of this invention, after the three-dimensional depth map of the image coordinate system is completed, the matrix transformation module 63 performs a geometric deformation matrix transformation on each of the plurality of sliced ​​images 800. In a preferred embodiment of the above modules, each module is a software program, and each module is executed by a processor (not shown) or control device 50 in the object shape image acquisition system 1 to achieve the function of the image processing module 60.

[0112] Please refer to the following: Figure 4A , Figure 5A and Figure 8 and refer to them together. Figure 11 A flowchart of the first embodiment of the object shape image capturing method of the present invention.

[0113] like Figure 4A , Figure 5A and Figure 11 As shown, the object shape image capturing method of the present invention is used in the object shape image capturing system 1 of the present invention. The following describes the steps of the object shape image capturing method of the present invention. Figure 11 As shown, the object shape image capturing method of the present invention includes steps S1 to S5.

[0114] Step S1: The photographic device 10 moves along the moving path 80 relative to the object to be measured 90, wherein the moving path 80 is not perpendicular to the focusing plane 15 on the side of the object to be measured.

[0115] like Figure 4A , Figure 5A and Figure 10 As shown, there are two ways in which the photographic device 10 moves relative to the object 90 along the moving path 80. Method 1: The photographic device 10 moves to capture an image. Two embodiments of the photographic device 10 along the first plane 70 are: the XY plane formed by the first axis transfer guide rail 21 and the second axis transfer guide rail 22 (the first plane 70 in Figure 5), or the inclined plane formed by the two transfer platforms of the photographic device 10 on the first axis transfer guide rail 21 and the third axis transfer guide rail 23. Figure 10 The first plane 70a) moves continuously while performing step S2: When the photographic device 10 moves along the moving path 80 relative to the object to be tested 90, the photographic device 10 acquires multiple slice images 800 of the object to be tested 90.

[0116] Method 2: The imaging device remains stationary, while the object under test 90 moves relative to the imaging device 10 along the first plane 70 in both embodiments. Simultaneously, while the object under test 90 moves, step S2 is executed: as the imaging device 10 moves relative to the object under test 90 along the moving path 80, the imaging device 10 acquires multiple slice images 800 of the object under test 90. It should be noted that the imaging effects of the two aforementioned moving imaging methods are the same. Method 2 (object under test 90 moves, imaging device 10 remains stationary) can be used for measurements on laboratory benchtop platforms requiring high-resolution object images and extremely high transfer accuracy.

[0117] Please refer to the following: Figure 12 , Figure 13A , Figure 13B , Figure 14A ,and Figure 14B This is to understand the schematic diagram of the image to be evaluated generated by the pixel offset superposition processing of the sliced ​​image in steps S3 to S5 of the present invention, and the processing method of converting the sliced ​​image from the image coordinate system three-dimensional depth map 710 with the normal 151 of the focusing plane of the object under test as the reference to the world coordinate system three-dimensional depth map 300 with the normal 71 of the first plane as the reference.

[0118] Step S3: Perform pixel offset superposition processing on multiple slice images according to magnification, image interval distance and focal plane deviation angle to generate multiple images to be evaluated.

[0119] Because the photographic apparatus of this invention performs continuous image acquisition while in motion, the positions of object points 92c, 92d, and 92e of the object under test 90 change continuously in different slice images 800, 800a, 800b, 800c, and 800d. Therefore, relative pixel translation regression correction is required to correctly overlay the positions of the object under test 90 in the slice images 800, 800a, 800b, 800c, 800d, and 800e to produce the desired image. Figure 13A The multiple images 700 shown are used for subsequent depth position evaluation (from blurred to clear and then back to blurred) to resolve the depth map of the image coordinate system with the clear distance focal layer index number (relative height). Specifically, this invention corrects the pixel offset of adjacent layers in the obliquely sliced ​​images 800a, 800b, 800c, 800d, and 800e by overlaying the images based on the adjacent image acquisition interval distance 890 and the image magnification of the photographic device.

[0120] like Figure 5A and Figure 12 As shown, the photographic device 10b is a conventional camera, consisting of... Figure 8It can be seen that along the moving path 80, for example, the photographic device 10b moves equidistantly to the left of the image. The normal 151 of the focusing surface of the photographic device 10b is parallel to the optical central axis 111 of the lens, and the normal 151 of the focusing surface is parallel to the normal 131 of the imaging plane of the image sensor. Therefore, at this time, the lens deviation angle 18 (θ, the angle between the normal 151 of the focusing surface and the normal 131 of the imaging plane of the image sensor) is equal to the focusing surface deviation angle 19 (ω, the angle between the normal 151 of the focusing surface and the normal 71 of the first plane), and the sensor deviation angle 17 (φ, the angle between the optical central axis 111 of the lens and the normal 131 of the imaging plane of the image sensor) is 0 degrees. It is also assumed that θ=ω=10 degrees and the magnification is 0.5X.

[0121] like Figure 12 As shown, the photographic device 10a captures cross-sectional images 800a, 800b, 800c, and 800d of a single object 90 on the focusing planes 15a, 15b, 15c, 15d, and 15e of the object under test, respectively. The contour feature points 92c, 92d, and 92e of the object 90 in the cross-sectional image 800a are represented by 820a, 830a, and 840a, respectively. The object points 92c, 92d, and 92e in the cross-sectional images 800b, 800c, and 800d are also presented in the same manner as in the cross-sectional image 800a. Figure 12 For ease of display, the specific positions of the photographic device 10a during movement are represented by the lens center points 16a, 16b, 16c, 16d, and 16e on the lens module 11, and the lens center points 16a, 16b, 16c, 16d, and 16e correspond to image reference points 817a, 817b, 817c, 817d, and 817e respectively in the sliced ​​images 800a, 800b, 800c, and 800d. Figure 12 It can be seen that in slice image 800a, the contour feature point image 820b of object point 92c and the mirror point 16b have a pixel offset T between the image reference point 817b of slice image 800a. The contour feature point image 820a of object point 92c and the mirror point 17a have a pixel offset T' between the image reference point 819a of slice image 800a, where T=2T'. The reason why the pixel offsets T and T' are different in slice images 800a, 800b, 800c, and 800d is that this invention takes slice image 800c as the center, and the image reference point 817c of slice image 800c as the central reference point. Therefore, the farther away from slice image 800c, the larger the pixel offset T. Assuming the total number of slice images is p+1, taking the p+1th slice image as the center reference point... The layer is the central slice, and the image acquisition interval between two adjacent slice images is q, which is 890. Layer and First The pixel offset T of each layer is q, and the pixel offset T of the first layer and the (p+1)th layer is q. This allows Figure 12 The sliced ​​images 800a, 800b, 800c, and 800d were generated after pixel offset overlay processing, as shown below. Figure 13A The image shown contains 700 images to be evaluated. Figure 13A As shown, object point 92c has a clear image in the post-alignment slice image 800c'.

[0122] Step S4: Use the Laplacian filter focus evaluation operation program with depth of focus (DFF) to evaluate the multiple images to be evaluated, so as to complete a three-dimensional depth map in an image coordinate system.

[0123] Specifically, step S4 follows the conventional technique of using the Laplacian filter focus evaluation operation procedure for depth of focus (DFF). From the series of images 700 to be evaluated, the image slice index number of the best focus (convolution operation value) is found for each pixel of the slice image of the object 90 (finding that 800c corresponding to 820c is the focus position of object point 92c), and the three-dimensional depth map 710 of the object image coordinate system 200 with the normal 151 of the focus plane of the object side as the reference coordinate is completed (e.g., Figure 13B As shown), assuming as Figure 13A As shown, object point 92c has a clear contour feature point image 820c in the aligned slice image 800c'. Therefore, the Laplace filter records the index number (relative height) of the aligned slice image 800c' corresponding to the clear contour feature point image 820c. It should be noted that the three-dimensional depth map 710 can present the outline 91 of the object 90 under test. The technical details of the Laplace filter focus evaluation calculation procedure for depth of focus (DFF) are known techniques, so its detailed calculation procedure will not be repeated here.

[0124] Step S5: Convert the three-dimensional depth map in the image coordinate system into a three-dimensional depth map in the world coordinate system based on the focal plane deviation angle and the image acquisition interval distance.

[0125] Furthermore, the three-dimensional depth map generated in step S4 is a three-dimensional depth map 710 generated in an image coordinate system with the normal 151 of the focusing plane of the object under test as the reference coordinate. Therefore, further image space transformation (step S5) is required, involving a spatial rotation matrix. , Where ω is the focal plane deviation angle 19(ω), the image coordinate system three-dimensional depth map 710 with the normal 151 of the focal plane on the side of the object to be measured as the reference coordinate is transformed into a world coordinate system three-dimensional depth map 300 (real world) with the normal 71 of the first plane as the reference, such as Figure 14A and Figure 14B As shown, the true three-dimensional depth dimension (3D point cloud) of the object under test 90 relative to the first plane 70 (XY plane) is obtained.

[0126] Please continue to refer to the following. Figure 4A , Figure 5A , Figure 6 , Figure 7 and Figure 9 and refer to them together. Figure 15 and Figure 16 The flowchart of the second embodiment of the object shape image capturing method of the present invention is provided to understand the image processing method of projection coordinate transformation with the focal plane corresponding to the trapezoidal distortion correction of the image sensor.

[0127] Because the object-side focusing plane 15 of the lens modules 11 and 11b (first and third embodiments) of the present invention is not parallel to the imaging plane 13 of the image sensor and has an angle, the object focusing plane in the multiple slice images 800a, 800b, 800c, 800d, and 800e obtained by the photographic device 10 will have perspective distortion. Therefore, the slice images 800a, 800b, 800c, 800d, and 800e need to be processed for spatial projection geometric transformation in order to correctly present the image position of the object 90 in the world coordinate system 300 with the first plane normal 71 as the reference.

[0128] like Figure 7 As shown, the basic thin lens optical imaging principle is based on the intersection of the focal point of the object being measured, the central ray, and parallel rays passing through the lens and then through the central focal point. If the image sensor is placed at this point, a clearly focused image point can be obtained, while other objects in front of and behind the object being measured will gradually become blurred. If two specific points (or three points, or a plane) that do not overlap in the field of view are desired, the tilt angle of the image sensor can be adjusted so that these two points (or three points, or a plane) are simultaneously clear. This is the Scheimpflug Intersection Principle of optical path imaging. The Scheimpflug Principle states that when a planar object is not parallel to the image plane, oblique tangent lines can be drawn from the image plane, the object plane, and the lens plane, and the intersection point is called the Scheimpflug intersection point. This invention applies this principle to determine the locked relationship between the lens deviation angle 18 (φ), the sensor deviation angle 17 (θ), and the focusing plane deviation angle 19 (ω).

[0129] Because the feature of this invention is that the photographic device 10 moves to acquire a sliced ​​image of the oblique focal plane of the object under test 90 (oblique sliced ​​image 800), the object under test 90 will be imaged at different positions along the path of the image sensor imaging surface of the image sensor imaging module 13. Therefore, for the lens modules 11 and 11b of this invention (first and third embodiments), as... Figure 15As shown, before performing pixel alignment along moving direction (step S3), a geometric matrix transformation step (step S21: perform a geometric deformation matrix transformation on each slice image 800) is required, whereby the focal plane corresponds to the image sensor spatial geometric matrix image coordinate transformation.

[0130] like Figure 16 As shown, according to the aforementioned Scheimpflug Intersection Principle, for the lens modules 11 and 11b of the present invention (first and third embodiments), the lens modules 11 and 11b are tilted, and their respective focal plane deviation angles 19(ω) ≠ 0. Figure 16 As shown, the image sensor imaging surface 13 of the lens module 11 in the first embodiment and the focusing plane 15 of the object under test on the object side will have a rectangular image sensor plane corresponding to a trapezoidal focusing plane. Projecting the object in the world coordinate system with the first plane normal 71 as the reference to the image coordinate system with the focusing plane normal 151 of the object under test as the reference coordinate will cause deformation. Therefore, multiple slice images 800 need to be transformed by a geometric deformation matrix so that the trapezoidal image included in each slice image obtained by the lens modules 11 and 11b can be transformed back into a rectangle in the world coordinate system. The coordinate system of the position pixels a(-20.5, 14.27), b(11.055, 7.70), c(-20.5, -14.27), d(11.055, -7.70) in the slice image 800 and the coordinate system of the feature points of the object under test A(-30, 20), B(30, 20), C(-30, -20), D(30, -20) on the focal plane 15 of the object under test is determined by... Figure 16 The transformation matrix shown is complete; the parameters of this matrix are based on... Figure 7 The Schiemfrug principle shown is obtained.

[0131] Please continue to refer to the following. Figure 4A , Figure 5A , Figure 6 , Figure 7 and Figure 9 and refer to them together. Figures 17 to 22 The flowchart of the third embodiment of the object shape image capturing method of the present invention is provided to understand the image processing method of projection coordinate transformation corresponding to the focal plane corresponding to the image sensor trapezoidal distortion correction.

[0132] like Figure 18 As shown, for ease of display, slice images 800, 800a, 800b, 800c, and 800d are all displayed on the screen. Figure 12 On the image sensing imaging surface 13. For example... Figure 18As shown, because the focal length and focus of the photographic device 10b are fixed, the contour feature point images 820 (image of object point 92c in slice image 800a), 830 (image of object point 92 in slice image 800a), and 840 (image of object point 92e in slice image 800a) corresponding to object points 92c, 92d, and 92e in the slice images 800a, 800b, 800c, and 800d acquired by the photographic device during its movement, along with object point 92c, 92d, and 92e, are generated. As objects 92d and 92e enter the field of view of the camera, object points 92c, 92d, and 92e gradually become clearer as they move closer to the focal point. Conversely, as object points 92c, 92d, and 92e move away from the focal point, they gradually become blurred. Meanwhile, the sliced ​​images 800, 800a, 800b, 800c, and 800d display contour feature point images 820, 830, and 840, which transition from blurry to clear and then back to blurry, facilitating subsequent depth position assessment. It should be noted that... Figure 18 The slice images 800, 800a, 800b, 800c, and 800d shown are the original images. Because the focal plane 15 of the object under test is tilted, the actual trapezoidal / rectangular shape of the focal plane 15 of the object under test is transformed into the corrected projected slice images 800*, 800a*, 800b*, 800c*, and 800d*. Figure 19 As shown, the present invention only illustrates the process of focusing the image of the object point on the focal plane corresponding to the image sensor when the lens module of the third embodiment moves to capture the image, from blurry to clear and then back to blurry. The first and second embodiments will also produce an image that is blurry to clear and then back to blurry when the lens module moves to capture the image, so they will not be described in detail.

[0133] like Figure 9 and Figure 5A As shown, in the third embodiment, if the image sensor 13 is set to be parallel to the moving path 80 on the first plane 70 (the measured point and the camera sensor module 13 maintain a fixed depth distance), since the sensor deviation angle 17 (φ) is equal to the lens deviation angle 18 (θ), the image state of the measured object during the moving image acquisition process does not change proportionally from focused to out of focus. Therefore, the trapezoidal correction of each slice before the shift can be postponed to after S4 to save computer computing power. At this time, the third embodiment's lens module 11b and the second embodiment's lens module 11a (telecentric lens is better, as described in paragraph 0007) only need to perform equidistant translation correction between slices before performing focused slice search to establish the three-dimensional object shape. If the sensor deviation angle 17 (φ) is not equal to the lens deviation angle 18 (θ), then the third embodiment's lens module 11b, like the first embodiment's lens module 11, must first perform a trapezoidal distortion geometric deformation matrix transformation on each slice image (step S21 needs to be executed), but if Figure 17 As shown, unlike the order in which the lens module 11 in the first embodiment performs step S21, the lens module 11b in the third embodiment performs step S21 after step S4 is completed.

[0134] The photographic device 10 uses the lens module 11b of the third embodiment to acquire a series of consecutive images (acquiring multiple sliced ​​images 800), such as... Figures 19 to 22 As shown. Figure 19 and Figure 20 As shown, the pixel offset of the image area of ​​adjacent slices is corrected according to the magnification of the imaging device 10 and the multiple image acquisition intervals, and a pixel offset superposition process is performed to generate multiple images 700 to be evaluated (see reference). Figure 13A (The relevant content will not be repeated) and execute the Laplacian filter focus evaluation operation program for depth of focus (DFF) to generate a three-dimensional depth map 710 of the object image coordinate system in image coordinate system 200. Figure 21 Finally, as Figure 22 As shown, image space transformation is performed (step S5), converting the three-dimensional depth map 710 in the image coordinate system to a three-dimensional depth map 300 in the world coordinate system (real world), thus obtaining the correct three-dimensional depth dimension (3D data point cloud) of the object to be measured 90 relative to the first plane 70 (XY plane).

[0135] The object shape image acquisition system 1, 1a of the present invention utilizes the feature that the moving path 80 of the photographic device 10 is not perpendicular to the focusing plane 15 of the object under test, so that the photographic device of the present invention only needs to acquire images at high speed and continuously in the horizontal direction (e.g., the X-axis or the XZ plane). This solves the problem in the prior art that when the object under test is larger than the field of view of the camera, the conventional photographic device 100a is idle and does not acquire images during the movement of the XY transfer platform or the movement of the object under test to the new field of view area of ​​the conventional photographic device 100a, resulting in low image acquisition utilization and detection capability of the conventional photographic device.

[0136] It should be noted that the above embodiments are merely examples for illustrative purposes, and the scope of the claims of this invention should be determined by the claims, and not limited to the above embodiments.

Claims

1. A system for capturing three-dimensional images of an object, characterized in that, The system, used to determine the shape and contour of an object by evaluating the focus quality changes of multiple slice images, includes: A photographic device includes a lens module and an image sensor imaging module, wherein the lens module and the image sensor imaging module form a focusing plane on the object to be measured. A moving device for moving the photographic apparatus relative to the object under test along a moving path, wherein the moving path is not perpendicular to the focusing plane of the object under test; and A control device electrically connected to the photographic device and the moving device is used to control the movement of the moving device and, when the photographic device moves along a moving path relative to the object under test, control the photographic device to acquire the multiple slice images of the object under test.

2. The system as described in claim 1, characterized in that, The moving device includes a first axis transfer guide rail, a second axis transfer guide rail, and a third axis transfer guide rail. Any two of the first axis transfer guide rail, the second axis transfer guide rail, and the third axis transfer guide rail form a first plane, allowing the photographic device to move relative to the object under test along the moving path on the first plane. A first plane normal of the first plane and a focal plane normal of the focal plane on the side of the object under test form a focal plane deviation angle, which is 0.1 degrees to 60 degrees.

3. The system as described in claim 2, characterized in that, The optical center axis of the lens module is perpendicular to the moving path, and the angle between the normal of the imaging plane of the image sensor module and the sensor deviation formed by the optical center axis of the lens is 0.1 degrees to 60 degrees.

4. The system as described in claim 2, characterized in that, The optical center axis of the lens module is not perpendicular to the moving path, and the lens deviation angle formed by the optical center axis of the lens and the moving path is 0.1 degrees to 60 degrees.

5. The system as described in claim 4, characterized in that, The normal to the imaging plane of the image sensor is parallel to the optical center axis of the lens.

6. The system as described in claim 4, characterized in that, The normal to the imaging plane of the image sensor is not parallel to the optical center axis of the lens, and the sensor deviation angle formed by the normal to the imaging plane of the image sensor and the optical center axis of the lens is 0.1 degrees to 60 degrees.

7. The system as described in claim 1, characterized in that, The camera takes pictures at a rate of 1 to 1000 times per second.

8. The system as described in claim 2, characterized in that, The photographic device has m units of image capture range along a moving direction. The moving path is a V-shaped path. When the photographic device completes the V-shaped path, the photographic device moves from the nth unit of image capture range to the (n+1)th unit of image capture range. n and m are natural numbers, and m > n.

9. The system as described in claim 8, characterized in that, There is a slice interval thickness between two adjacent slice images. The V-shaped path has a down path and an up path, wherein the depth difference between the end point of the down path and the start point of the up path is 0.5 times the slice interval thickness.

10. The system as described in claim 2, characterized in that, The system also includes an image processing module that is signal-connected to the control device. The camera moves along the moving path relative to the object under test at a magnification and acquires multiple slice images of the object under test. The spacing between adjacent slice images is an image acquisition interval. The image processing module performs a pixel offset superposition process on the multiple slice images according to the magnification, the image acquisition interval, and the focal plane deviation angle to generate multiple images to be evaluated.

11. The system as claimed in claim 10, characterized in that, The image processing module includes an evaluation module that uses a Laplacian filter focusing evaluation operation program based on depth of focus (DFF) to evaluate the multiple images to be evaluated, thereby completing a three-dimensional depth map in an image coordinate system.

12. The system as described in claim 10, characterized in that, The image processing module includes an image space conversion module, which converts the three-dimensional depth map in the image coordinate system into a three-dimensional depth map in the world coordinate system based on the focal plane deviation angle and the image acquisition interval distance 890.

13. The system as described in claim 10, characterized in that, The image processing module includes a matrix transformation module. When the image sensor imaging module is not parallel to the focusing plane of the object under test, before the image processing module performs pixel offset superposition processing on each of the plurality of slice images, the matrix transformation module performs a geometric deformation matrix transformation on each of the plurality of slice images.

14. The system as claimed in claim 10, characterized in that, The image processing module includes a matrix transformation module. When the image sensor imaging module is not parallel to the focusing plane of the object under test, after the three-dimensional depth map of the image coordinate system is completed, the matrix transformation module performs a geometric deformation matrix transformation on each of the multiple slice images.

15. A method for capturing a three-dimensional shape image of an object, characterized in that, A method for moving a photographic device relative to an object under test via a moving device to acquire multiple slice images of the object under test and determining the external contour of the object under test by evaluating the focus quality changes of the multiple slice images, wherein the photographic device includes a lens module and an image sensor imaging module, wherein the lens module and the image sensor imaging module form a side focal plane of the object under test, the method includes the following steps: The photographic device moves relative to the object under test along a moving path, wherein the moving path is not perpendicular to the focusing plane of the object under test; and When the photographic device moves along a moving path relative to the object under test, the photographic device acquires multiple slice images of the object under test.

16. The method as described in claim 15, characterized in that, The photographic device moves relative to the object under test along the moving path on a first plane. A normal of the first plane and a normal of the focal plane on the side of the object under test form a focal plane deviation angle. The photographic device moves relative to the object under test along the moving path at a magnification and acquires multiple slice images of the object under test. The spacing between adjacent slice images has an image acquisition interval distance. The method includes: Based on the magnification, the image acquisition interval, and the focal plane deviation angle, multiple sliced ​​images are overlaid with a one-pixel offset to generate multiple images to be evaluated; and The multiple images to be evaluated are evaluated using a Laplacian filter focusing evaluation program based on depth of focus (DFF) to complete a three-dimensional depth map in an image coordinate system.

17. The method as described in claim 16, characterized in that, The focusing plane deviation angle ranges from 0.1 degrees to 60 degrees.

18. The method as described in claim 16, characterized in that, It also includes converting the three-dimensional depth map of the image coordinate system into a three-dimensional depth map of the world coordinate system based on the normal of the first plane, according to the included angle of the focus plane deviation and the image acquisition interval distance.

19. The method as described in claim 16, characterized in that, When the image sensor imaging module is not parallel to the focusing plane of the object under test, before performing the pixel offset superposition processing on each slice image, the method further includes: Perform a geometric deformation matrix transformation on each slice image.

20. The method as described in claim 16, characterized in that, When the image sensor imaging module is not parallel to the focusing plane of the object under test, after the three-dimensional depth map of the image coordinate system is completed, the method further includes: Perform a geometric deformation matrix transformation on each slice image.

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