Scanning device and scanning method
By combining high-speed photosensitive elements and general photosensitive elements, the problem of inaccurate movement trajectory caused by low frame rate in existing scanning devices is solved, enabling accurate scanning of teeth and oral tissues and improving scanning quality.
Patent Information
- Application Number
- CN202410751089.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-05-20
- Filing Date
- 2024-06-12
- Publication Date
- 2025-11-21
AI Technical Summary
Existing scanning devices, due to their use of low-frame-rate photosensitive elements, struggle to calculate accurate movement trajectories, particularly in oral scanning where the classification and evaluation of images of teeth and tissue surfaces are difficult.
By combining a high-speed photosensitive element with a general photosensitive element, and through a displacement calculation unit and a data processing unit, the high frame rate of the high-speed photosensitive element is used to calculate the accurate movement trajectory, and combined with the high-resolution image data of the general photosensitive element, the accurate movement trajectory of the scanned target object is achieved.
It enables precise calculation of the movement trajectory of teeth and oral tissues during scanning, improving the accuracy and precision of scanning, reducing errors, and enhancing scanning quality.
Smart Images
Figure CN120982964A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to scanning apparatus and scanning method, and particularly to scanning apparatus and scanning method that simultaneously possesses a general photosensitive element and a high-speed photosensitive element, enabling the acquisition of more accurate motion trajectories. Background Technology
[0002] Typical scanning devices, such as dental scanners, primarily use cameras (or optical cameras) with high-resolution photosensitive elements to capture images of teeth and / or tissue surfaces as they move along the inner surface of the oral cavity. The camera's movement trajectory within the oral cavity can be used to classify and assess the health status of different areas. However, the photosensitive elements used in typical cameras have a low frame rate (Frames Per Second, FPS), making it difficult to calculate accurate movement trajectories. Summary of the Invention
[0003] In view of this, the scanning device and scanning method provided by the present invention introduce a high-speed photosensitive element to assist in the calculation of the movement trajectory. By utilizing the characteristics of the high-speed photosensitive element, the scanning device simultaneously possesses a camera (general photosensitive element) and a high-speed photosensitive element, enabling the acquisition of a more accurate movement trajectory while scanning the target object.
[0004] A scanning apparatus according to an embodiment of the present invention includes: a first photosensitive element (first imaging device), a second photosensitive element (second imaging device), a displacement calculation unit, and a data processing unit. The first photosensitive element scans or captures a target object at a first frame rate to acquire multiple first frame rate images. The second photosensitive element scans or captures the target object at a second frame rate higher than the first frame rate to acquire multiple consecutive second frame rate images. The displacement calculation unit receives the second frame rate images, calculates the positional change between every two adjacent images in the second frame rate images, and generates multiple displacement data between every two adjacent images accordingly. The data processing unit, based on the displacement data, determines the displacement amount between a current image received from the first frame rate images and a previous image.
[0005] In some of the aforementioned embodiments, the data processing unit further sums up multiple displacement data between every two adjacent images in the second frame rate image obtained during the period from receiving the previous image to receiving the current image, in order to obtain the displacement amount between the current image and the previous image.
[0006] In some of the aforementioned embodiments, the displacement calculation unit further performs the following steps: performing image comparison on two adjacent first and second images in the second frame rate image; identifying a first block and a second block with high similarity in the first and second images respectively; and calculating the displacement of the first block and the second block in the first and second images based on their relative positions, as the displacement data.
[0007] In some of the aforementioned embodiments, the displacement calculation unit identifies a first block and a second block with high similarity based on the highest correlation coefficient or the smallest error.
[0008] In some of the foregoing embodiments, the first photosensitive element has a first resolution, the second photosensitive element has a second resolution, and the second resolution is lower than the first resolution.
[0009] In some of the foregoing embodiments, the first photosensitive element and the second photosensitive element are arranged adjacent to each other in the scanning device. Furthermore, the scanning device is an oral scanning device, and the target object is teeth or oral tissue. In addition, the scanning device also includes one or more light sources.
[0010] A scanning method according to another embodiment of the present invention includes the following steps. First, a target object is captured using a first photosensitive element (first imaging device) having a first frame rate, obtaining a plurality of first frame rate images. Then, the target object is captured using a second photosensitive element (second imaging device) having a second frame rate, obtaining a plurality of consecutive second frame rate images, wherein the second frame rate is higher than the first frame rate. Next, for every two adjacent images in the consecutive second frame rate images, the positional change between each pair of adjacent images is calculated to generate a plurality of displacement data between each pair of adjacent images. Then, based on the displacement data, the displacement amount between a current image received from the first frame rate images and the previous image of the current image is determined.
[0011] In some of the foregoing embodiments, the scanning method further includes summing multiple displacement data between every two adjacent images in the second frame rate image obtained during the period from receiving the previous image to receiving the current image, so as to obtain the displacement between the current image and the previous image. Attached Figure Description
[0012] Figure 1 This diagram shows a scanning device according to an embodiment of the present invention.
[0013] Figure 2 This diagram shows the displacement of feature blocks TP1 and TP2 in two adjacent images Pn and Pn+1 in the second frame rate image.
[0014] Figure 3 This embodiment shows a time series diagram of the displacement data stream and image data stream.
[0015] Figure 4 A flowchart is shown showing the scanning method applied to the scanning device of the present invention.
[0016] [Symbol Explanation]
[0017] 10: Scanning device
[0018] 101: General photosensitive element (first imaging device)
[0019] 102: High-speed photosensitive element (second imaging device)
[0020] 103: Displacement Calculation Unit
[0021] 104: Data Processing Unit
[0022] 105: Light source
[0023] 106: Target Object
[0024] Pn, Pn+1: Adjacent second frame rate images
[0025] TP1, TP2: Feature blocks
[0026] 40: Flowchart
[0027] S41-S46: Steps Detailed Implementation
[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings.
[0029] Figure 1 This diagram shows a scanning device 10 according to an embodiment of the present invention. Figure 1 The scanning device 10 includes a first imaging unit 101, a second imaging unit 102, a displacement calculation unit 103, a data processing unit 104, and at least one light source 105. The light source 105 is, for example, but not limited to, a light-emitting diode (LED).
[0030] The first imaging unit 101 and the second imaging unit 102 can be two separate cameras (not shown) or integrated into a single camera (not shown). The first imaging unit 101 can be a general photosensitive element; while the second imaging unit 102 can be a high-speed photosensitive element. In this embodiment, the imaging unit broadly refers to any device capable of scanning or photographing an object to form an image, and in some respects, it functions equivalent to a photosensitive element. For ease of description, the general photosensitive element will be designated as 101, and the high-speed photosensitive element as 102.
[0031] In this embodiment, a comparison between the general photosensitive element 101 and the high-speed photosensitive element 102 is shown in Table 1 below.
[0032] Table 1
[0033]
[0034]
[0035] Table 1 is merely an example and is not intended to limit the present invention. However, as can be seen from Table 1, the frame rate (Frames Per Second, FPS) of a high-speed image sensor is higher than that of a general image sensor; while the resolution of a high-speed image sensor is lower than that of a general image sensor. In this embodiment, the high-speed image sensor is used to track the displacement of image blocks on the surface of the scanned target object, thus requiring a higher frame rate but using a lower resolution. A general image sensor, on the other hand, is used to capture high-quality images, thus requiring higher resolution but not a high frame rate. Based on the above, in this embodiment, the frame rate of the high-speed image sensor used is higher than that of a general image sensor, while the resolution of the high-speed image sensor is lower than that of a general image sensor. Furthermore, both the high-speed and general image sensors can be, for example, CMOS image sensors, but are not limited thereto. Hereinafter, the frame rate of the general image sensor will be referred to as the first frame rate, and the frame rate of the high-speed image sensor will be referred to as the second frame rate.
[0036] In this embodiment, the first photosensitive element 101 and the second photosensitive element 102 are arranged as close as possible to each other within the scanning device 10.
[0037] Figure 1 In the process, when scanning the target object 106, the scanning device 10 illuminates the target object 106 with a light source 105. A general photosensitive element (first imaging unit) 101 and a high-speed photosensitive element (second imaging unit) 102 receive the reflected light from the target object 106 and respectively generate a first frame rate image and a second frame rate image. Figure 1 The arrow in the image indicates the direction of movement of the scanning device 10.
[0038] The displacement calculation unit 103 calculates the positional change between every two adjacent images in the second frame rate image, thereby generating multiple displacement data between every two adjacent images. Here, adjacent images refer to two images that are consecutive in the time series.
[0039] Specifically, in consecutive second-frame-rate images captured by the high-speed image sensor 102, because any two adjacent images, such as images Pn and Pn+1 captured at time t=n and time t=n+1, have a very short time difference due to the high frame rate of the high-speed image sensor 102, the displacement calculation unit 103 can find the same feature blocks in images Pn and Pn+1. Figure 2 As shown, the same feature blocks TP1 and TP2 can be found by using the images Pn and Pn+1 taken at time t=n and time t=n+1 in the second frame rate image.
[0040] To identify identical feature blocks TP1 and TP2, the displacement calculation unit 103 first performs image comparison on two adjacent images Pn and Pn+1 in the second frame rate image, identifying highly similar feature blocks TP1 and TP2 in images Pn and Pn+1 respectively. In this embodiment, the displacement calculation unit 103 performs image comparison by, for example, using feature block TP1 in image Pn as a feature, moving it in image Pn+1 and calculating its similarity to find the position of the similar feature block TP2. The similarity can be calculated using, for example, the maximum correlation efficient method or the minimum error method, such as the minimum mean-square error (MMSE).
[0041] After locating the feature block TP2 in image Pn+1, the displacement calculation unit 103 calculates the positional changes of feature blocks TP1 and TP2 based on their relative positions. In other words, it calculates the displacement (Δx and Δy) of feature block TP1 from its position in image Pn to its position in image Pn+1, which is then used as the displacement data Δ(x, y). t .
[0042] The displacement calculation unit 103, for the received second frame rate image, obtains the displacement relationship (Δx and Δy) between any two adjacent images (such as Pn and Pn+1 as described above) in the manner described above, and continuously outputs the calculated displacement data Δ(x, y) accordingly. t The output frequency of the displacement data is the same as the second frame rate. In this way, the scanning trajectory of the scanning device 10 can be determined.
[0043] The general photosensitive element 101 outputs the first frame rate image as image data, for example, at the output frequency of the first frame rate. In addition, the scanning device 10 of the present embodiment further has a memory (not shown), which can be used as a buffer device for displacement data and / or image data.
[0044] Since the displacement data and the image data are heterogeneous data, and their data frequencies and attributes are different, further data processing is required to integrate the two. Hereinafter, the operation of the data processing unit 104 of the scanning device 10 in this example will be described in detail.
[0045] Figure 3 Show the time series schematic diagram of the displacement data stream and the image data stream of the present embodiment. Figure 3 In it, Δ(x, y) represents the displacement data, n represents the time of each piece of displacement data, and Δ(x, y) t＝n 、Δ(x, y) t＝n+1 、Δ(x, y) t＝n+2 … respectively represent the displacement data Δ(x, y) at times t = n, t = n + 1, and t = n + 2 …. Figure 3 In it, m represents the time of each piece of image data, and IMG t＝m represents the image data at time t = m. When the data processing unit 104 receives the image data IMG t＝m , it will calculate the total displacement between this image (referred to as the current image) IMG t＝m and the previous image IMG t＝m-1 :
[0046]
[0047] where d is the time gap between two images in the image (first frame rate image) data stream (for example, the time gap between the current image and the previous image), and δ(x, y) t＝m represents the sum of the displacements Δ(x, y) of all two adjacent second frame rate images during the period of m - d < t ≤ m t＝m-d+1 to Δ(x, y) t＝m , that is, it represents the displacement between the previous image and the current image.
[0048] Finally, taking time t = m as an example, the data form output by the data processing unit 104 is (IMG t＝m , δ(x, y) t＝m ). In this way, the current image and the displacement between this current image and the previous image can be associated with each other.
[0049] In this embodiment, the scanning device 10 is, for example, an oral scanning device, and the target object is teeth or oral tissue. Based on the foregoing, the scanning device 10 can output image-to-displacement (IMG) data. t , δ(x,y) t Therefore, the displacement data δ(x, y) can be used. t To construct a precise scanning (movement) trajectory, paired with corresponding image data (IMG). t It can reduce errors and obtain high-quality results when modeling and constructing panoramic images.
[0050] In this embodiment, the scanning device 10 may have hardware such as a digital signal processor (DSP), a controller, an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA), and implements the functions of the displacement processing unit 103 and the data processing unit 104 by loading a program, but is not limited to this.
[0051] Figure 4 A flowchart 40 shows the scanning method applied to the scanning device 10 of the present invention. First, after the scanning device 10 starts operating, in step S41, a target object is captured by a general photosensitive element 101 having a first frame rate (FPS), acquiring multiple first frame rate images; and in step S42, the target object is captured by a high-speed photosensitive element 102 having a second frame rate, acquiring multiple consecutive second frame rate images as image data. The second frame rate is higher than the first frame rate, and the resolution of the high-speed photosensitive element 102 is lower than that of the general photosensitive element 102. Next, in step S43, the displacement calculation unit 103 calculates the positional change between each pair of adjacent images in the consecutive second frame rate images, generating multiple displacement data between each pair of adjacent images. In step S44, the displacement data and the image data corresponding to the first frame rate images are stored in a memory buffer. In step S45, the data processing unit 104, based on the displacement data, calculates the displacement between a current image received from the first frame rate images and the previous image of the current image. Finally, in step S46, the data processing unit 104 outputs a higher resolution current image and the displacement between the current image and the previous image.
[0052] The scanning method of this embodiment further includes summing multiple displacement data between every two adjacent images in the second frame rate image obtained from the period from receiving the previous image to receiving the current image, so as to obtain the displacement amount between the current image and the previous image.
[0053] The embodiments of the present invention have been described in detail above. It should be noted that the above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the scope of the invention. Those skilled in the art can modify and alter the embodiments without departing from the technical principles and spirit of the present invention. Therefore, the scope of protection of the present invention should be determined by the description in the following claims.
Claims
1. A scanning device that can obtain precise location information while scanning a target object, comprising: The first imaging device scans or captures the target object at a first frame rate (Frame Per Second, FPS) to obtain multiple images at the first frame rate. The second imaging device scans and captures the target object at a second frame rate higher than the first frame rate, thereby obtaining multiple consecutive second frame rate images. The displacement calculation unit calculates the positional change between each pair of adjacent images in the second frame rate image, and generates multiple displacement data accordingly. as well as The data processing unit, based on the aforementioned displacement data, calculates the displacement between the current image received from the first frame rate image and the previous image.
2. The scanning device as claimed in claim 1, wherein, The data processing unit sums up multiple displacement data between every two adjacent images in the second frame rate image obtained during the period from receiving the previous image to receiving the current image, so as to obtain the displacement between the current image and the previous image.
3. The scanning device as described in claim 2, wherein, The aforementioned displacement calculation unit also performs: Image comparison is performed on two adjacent first and second images in the second frame rate image described above; In the first image and the second image mentioned above, respectively, identify the first block and the second block with high similarity; Based on the relative positions of the first block and the second block, the displacement of the first block and the second block in the first image and the second image is calculated and used as the displacement data.
4. The scanning device as claimed in claim 3, wherein, The displacement calculation unit identifies the first block and the second block with high similarity based on the highest correlation coefficient or the smallest error.
5. The scanning device as claimed in claim 1, wherein, The first imaging device has a first resolution, the second imaging device has a second resolution, and the second resolution is lower than the first resolution.
6. The scanning apparatus as claimed in claim 1, wherein, The first imaging device and the second imaging device are arranged adjacent to each other in the scanning device.
7. The scanning apparatus as claimed in claim 1, wherein, The aforementioned scanning device is an oral cavity scanning device, and the aforementioned target object is teeth or oral tissue.
8. The scanning device as claimed in claim 1 further includes one or more light sources.
9. A scanning method that can obtain precise location information while scanning a target object, comprising: The target object is captured by a first imaging device having a first frame rate (Frame per second, FPS), and multiple images of the first frame rate are obtained. The target object is captured by a second imaging device having a second frame rate, and multiple consecutive images with a second frame rate are obtained, wherein the second frame rate is higher than the first frame rate. For each pair of adjacent images in the aforementioned consecutive second frame rate images, the positional change in each pair of adjacent images is calculated to generate multiple displacement data between each pair of adjacent images; as well as Based on the displacement data mentioned above, the displacement between the current image received from the first frame rate image and the previous image of the current image is obtained.
10. The scanning method as described in claim 9, further comprising: The displacement data between each pair of adjacent images in the second frame rate image obtained during the period from receiving the previous image to receiving the current image are summed to obtain the displacement between the current image and the previous image.