A method for identifying fast-moving targets

Abstract

The present invention provides a method for identifying fast-moving targets, which is applied to the technical field of astronomical target identification, and includes: acquiring a series of sequential observation images containing fast-moving targets and establishing an image database, wherein the series of sequential observation images includes multiple original observation images; respectively preprocessing the multiple original observation images; respectively performing astronomical position calibration on the preprocessed multiple original observation images; performing color assignment on each original observation image after preprocessing and astronomical position calibration; merging and superimposing the multiple original observation images after color assignment to obtain a target observation image; and identifying the fast-moving targets based on the dynamic trajectories in the target observation image. The fast-moving targets identified by this method simultaneously satisfy specific color characteristics and straight-line motion trajectories, and can improve the accuracy of identification and the stability of the recognition rate.

Description

Technical Field

[0001] The present invention relates to the technical field of astronomical target recognition, and particularly to a method for recognizing fast-moving targets. Background Art

[0002] In the observation images in the current fields of astronomy and space technology, due to the similarity in color and morphology between fast-moving targets and background stars, it is difficult to distinguish between stars, planets, and space debris targets, especially under the influence of background noise and target feature similarity.

[0003] To address this problem, the currently developed technologies mainly include background subtraction, inter-frame difference method, and optical flow method, etc. The background subtraction method detects the regions with a difference from the background exceeding a certain threshold as the moving regions by comparing the current frame with the background model; the inter-frame difference method determines the moving regions by calculating the pixel value differences between several consecutive frames of images and then performing threshold processing. However, when the size of the moving target is small, more errors will be introduced through background subtraction or subtraction of inter-frame images, making it difficult to detect the target; the optical flow method utilizes the motion information of pixel points in the image sequence to track the moving target through the optical flow equation, but the optical flow method usually assumes that the motion of objects in the scene is within a small range. For fast-moving or large-range moving objects, the optical flow method may not be able to accurately estimate the motion. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] In view of the above deficiencies, the main object of the present invention is to provide a method for recognizing fast-moving targets, which fuses color features and motion features to quickly locate and recognize fast-moving targets, thereby ensuring timely monitoring of fast-moving targets mainly including space debris targets and near-Earth asteroids, and being able to detect crisis moments in a timely manner and intervene in a timely manner.

[0006] (II) Technical Solutions

[0007] To achieve the above object, the present invention provides a method for recognizing fast-moving targets, including: acquiring a series of sequential observation images containing fast-moving targets and establishing an image database, where a series of sequential observation images includes multiple original observation images; respectively preprocessing the multiple original observation images; respectively performing astronomical position calibration on the preprocessed multiple original observation images; performing color assignment on each original observation image after preprocessing and astronomical position calibration; merging and superimposing the multiple original observation images after color assignment to obtain a target observation image; and recognizing fast-moving targets based on the dynamic trajectories in the target observation image.

[0008] In the above solution, a series of sequential observation images includes at least 3 original observation images; and multiple original observation images in a series of sequential observation images are acquired at a preset time interval.

[0009] In the above solution, preprocessing is performed on multiple original observation images respectively. Among them, the preprocessing includes: correcting the background image and the flat-field image for each of the multiple original observation images; and removing cosmic rays from each of the original observation images.

[0010] In the above solution, astronomical position calibration is performed on the multiple preprocessed original observation images respectively, including: performing astronomical position calibration on the original observation images respectively through WCS (World Coordinate System) to determine the specific positions on the celestial sphere to which the pixel points on the original observation images are mapped.

[0011] In the above solution, color assignment is performed on each of the original observation images that have been preprocessed and astronomically position-calibrated, and the colors of each of the original observation images after color assignment are all different.

[0012] In the above solution, the multiple original observation images after color assignment are combined and superimposed to obtain a target observation image, including: taking the astronomical position as a reference, combining and superimposing the multiple original observation images after color assignment in a series of time-sequence observation images to obtain a single target observation image.

[0013] In the above solution, fast-moving targets are identified based on the dynamic trajectories in the target observation image, including: determining one or more dynamic trajectories formed by the convergence of targets of different colors in the target observation image.

[0014] In the above solution, identifying fast-moving targets based on the dynamic trajectories in the target observation image further includes: when the dynamic trajectory is a straight line, determining the straight-line motion trajectory as the trajectory of a fast-moving target in space; and identifying the fast-moving target according to the trajectory of the fast-moving target in space.

[0015] (III) Beneficial effects

[0016] The technical solution of the embodiment of the present invention has at least the following beneficial effects:

[0017] (1) By performing color assignment on the time-sequence observation images, the method aligns a series of time-sequence images after color assignment according to the astronomical coordinate positions and directly combines the images to obtain an observation image that simultaneously has color characteristics and motion trajectory characteristics. Fast-moving targets are manifested as straight-line motion trajectories composed of different-color target sources in the image. The fast-moving targets identified by this method simultaneously satisfy specific color characteristics and straight-line motion trajectories, which can improve the accuracy of identification and the stability of the recognition rate.

[0018] (2) This method can more effectively identify fast-moving targets from complex backgrounds, not only ensuring the uniqueness of extracting fast-moving targets, but also having no other potential interferences, thereby providing more accurate and stable recognition features, improving the efficiency and accuracy of recognition, and enhancing the subsequent precise monitoring of fast-moving targets. Description of the Drawings

[0019] Figure 1 Schematically shows a flowchart of a method for identifying fast-moving targets according to an embodiment of the present invention;

[0020] Figure 2 Shows a series of time-sequential observation images according to an embodiment of the present invention;

[0021] Figure 3 Shows a colorized image of an observation image after preprocessing and astronomical position calibration according to an embodiment of the present invention;

[0022] Figure 4 Shows an effect diagram of a target observation image according to an embodiment of the present invention;

[0023] Figure 5 Shows an effect diagram of identifying a space debris target according to an embodiment of the present invention;

[0024] Figure 6 Shows an effect diagram of synthesizing a multi-color time-sequence diagram according to an embodiment of the present invention. Detailed Embodiments

[0025] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0026] The terms used herein are merely for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0027] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0028] Figure 1 Schematically shows a flowchart of a method for identifying a fast-moving target according to an embodiment of the present invention.

[0029] Please refer specifically to Figure 1 In an embodiment of the present invention, the method for identifying a fast-moving target specifically includes steps S110 to S160.

[0030] Step S110, obtain a series of sequential observation images including the fast-moving target and establish an image database, where the series of sequential observation images includes multiple original observation images.

[0031] In an embodiment of the present invention, the series of sequential observation images includes at least 3 original observation images; and a plurality of original observation images in the series of sequential observation images are obtained at a preset time interval.

[0032] Specifically, in order to obtain the position change of the fast-moving target, there needs to be a certain time interval between the observation shooting times of the multiple original observation images that make up the database, for example, it can range from several minutes to half an hour.

[0033] It should be noted that when observing the target for shooting, in order to obtain better motion trajectory features, the target is generally shot at the same time interval, but different interval durations are also possible. In addition, in order to obtain a complete motion trajectory and more motion trajectory data points, it is necessary to ensure that the number of original observation images in the series of sequential images for observation is greater than 3.

[0034] For example, shoot multiple FITS format images including the fast-moving target and establish a processing database. The normal background of a FITS image is gray, and the white bright sources are various celestial bodies. When observing the target for shooting, the target is shot with the same exposure duration and the same interval time, and the sequential observation images are saved for subsequent processing.

[0035] Step S120, perform preprocessing on the multiple original observation images respectively.

[0036] In an embodiment of the present invention, perform preprocessing on the multiple original observation images respectively, where the preprocessing includes: correcting the background image and flat-field image for each of the multiple original observation images; and removing cosmic rays from each of the original observation images.

[0037] Specifically, in order to exclude the interference items brought by the machine to the original observation images, preprocessing is performed on the multiple original observation images respectively to correct the background image and flat-field image, and remove cosmic rays from each of the original observation images, etc.

[0038] Step S130, perform astronomical position calibration on the multiple preprocessed original observation images respectively.

[0039] In an embodiment of the present invention, astronomical position calibration is performed on multiple preprocessed original observation images respectively, including: performing astronomical position calibration on the original observation images respectively through WCS (World Coordinate System) to determine the specific positions on the celestial sphere to which the pixel points on the original observation images are mapped.

[0040] Specifically, performing astronomical position calibration on multiple preprocessed original observation images respectively is an important step in astronomical data processing, which ensures the precise alignment of the images and the accuracy of subsequent analysis.

[0041] The WCS (World Coordinate System) system is used for astronomical position calibration. It is a coordinate system for astronomical images that describes the geometric transformation relationship between the pixel coordinates of the image and the celestial coordinates. WCS can map the pixel points on the original observation image to specific positions on the celestial sphere, so that the relative relationship between the position of the celestial body and the original observation image can be accurately determined.

[0042] Step S140: Perform color assignment on each original observation image that has been preprocessed and astronomically position-calibrated.

[0043] In an embodiment of the present invention, color assignment is performed on each original observation image that has been preprocessed and astronomically position-calibrated, and each original observation image after color assignment has a different color.

[0044] Exemplarily, a color assignment is performed on each single image in a series of sequential observation images to ensure that each image in the sequential images has a different color. For example, the colors can refer to the common RGB color combination, where RGB respectively represent Red, Blue, and Green, or refer to the CMYK color combination, which respectively represent Cyan, Magenta, Yellow, and Black. According to the number of original observation images in the sequential observation images, various color combinations can be set or combined.

[0045] Step S150: Merge and stack the multiple original observation images after color assignment to obtain a target observation image.

[0046] In an embodiment of the present invention, merging and stacking the multiple original observation images after color assignment to obtain a target observation image includes: taking the astronomical position as a reference, merging and stacking the multiple original observation images after color assignment in a series of sequential observation images to obtain a single target observation image.

[0047] Step S160: Identify fast-moving targets based on the dynamic trajectories in the target observation image.

[0048] In an embodiment of the present invention, based on the dynamic trajectories in the target observation image, fast-moving targets are identified, including: determining one or more dynamic trajectories formed by the convergence of targets of different colors in the target observation image. When the dynamic trajectory is a straight line, determining the straight-line motion trajectory as the spatial fast-moving target trajectory; and identifying the fast-moving target according to the spatial fast-moving target trajectory.

[0049] Exemplarily, search for one or more dynamic trajectories formed by the convergence of circular targets of different colors or short lines of different colors in the superimposed target observation image. Fast-moving targets appear as straight-line motion trajectories composed of target sources of different colors in the image. Therefore, when the dynamic trajectory is a straight line, determine the straight-line motion trajectory as the spatial fast-moving target trajectory; and identify the fast-moving target according to the spatial fast-moving target trajectory.

[0050] It can be seen that when the identified fast-moving target simultaneously satisfies specific color characteristics and a straight-line motion trajectory, this trajectory is the spatial fast-moving target trajectory. The spatial fast-moving target trajectory can intuitively reflect the position and motion state of the fast-moving target.

[0051] Through the embodiment of the present invention, the method for identifying fast-moving targets using color characteristics and motion trajectories can, compared with the prior art, more effectively identify fast-moving targets from a complex background, not only ensuring the uniqueness of the extracted fast-moving targets, with almost no other potential interference, thus providing more accurate and stable identification features, improving the efficiency and accuracy of identification, and improving the subsequent precise monitoring of fast-moving targets.

[0052] Based on the above method for identifying fast-moving targets, the present invention is illustrated by taking a series of time-sequence observation images including 3 original observation images as an example.

[0053] Figure 2 Shows a series of time-sequence observation images according to an embodiment of the present invention.

[0054] As Figure 2 shown, this series of time-sequence observation images includes 3 original observation images in FITS format. The white target source within the green circle is a near-Earth asteroid target, and the remaining white target sources are stars.

[0055] Furthermore, preprocess the 3 original observation images respectively to correct the background image and the flat-field image and remove cosmic rays from each original observation image.

[0056] Furthermore, perform astronomical position calibration on the 3 preprocessed original observation images respectively to ensure the precise alignment of the images and the accuracy of subsequent analysis.

[0057] Figure 3Shows a colorized image of the observed image after preprocessing and astronomical position calibration according to an embodiment of the present invention.

[0058] As Figure 3 shown, three colors, namely red, green, and blue, are respectively used to colorize the set of images, and the near-Earth asteroid target is within the green circle.

[0059] Figure 4 Shows the effect diagram of the target observation image according to an embodiment of the present invention. Figure 5 Shows the effect diagram of identifying space debris targets according to an embodiment of the present invention. Figure 6 Shows the synthesis effect diagram of the multi-color time series diagram according to an embodiment of the present invention.

[0060] Furthermore, a series of 3 original observed images that have been colorized are merged and superimposed based on the astronomical position to obtain a single target observation image. The synthesis effect is as Figure 4 shown. In the image, two dynamic trajectories (marked by the green frame) formed by the convergence of red, green, and blue dot targets are obtained. For another example, Figure 5 is the synthesis effect diagram when identifying space debris. In addition, when setting multiple color combinations, such as Figure 6 the synthesis effect diagram of the multi-color time series diagram shown. It can be seen that by combining the color and straight-line trajectory features, the position and motion state of the fast-moving target can be intuitively reflected.

[0061] Through the embodiments of the present invention, by assigning colors to the time series observed images, a series of time series images after color assignment are aligned according to the astronomical coordinate positions and directly merged to obtain an observed image with both color features and motion trajectory features. The fast-moving target appears as a straight-line motion trajectory composed of different color target sources in the image. The fast-moving target identified by this method needs to satisfy specific color features and a straight-line motion trajectory at the same time, which can improve the accuracy of identification and the stability of the recognition rate.

[0062] The above specific embodiments have further detailed the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for identifying fast-moving targets, applied to the identification of astronomical targets, characterized in that: include: Acquire a series of time-series observation images containing fast-moving targets and establish an image database, wherein the series of time-series observation images include a plurality of original observation images; Preprocessing the multiple original observation images respectively; Perform astronomical position calibration on multiple pre-processed original observation images respectively; Assigning a color to each original observed image after preprocessing and astronomical position calibration, wherein the color of each original observed image after color assignment is different; The multiple original observation images after color assignment are combined and superimposed to obtain the target observation image; Based on the dynamic trajectory in the target observation image, a fast-moving target is identified.

2. The method for identifying fast-moving targets according to claim 1, characterized in that: The series of time-series observation images includes at least 3 original observation images; and A plurality of original observation images in the series of time-series observation images are acquired at preset time intervals.

3. The method for identifying fast-moving targets according to claim 1, characterized in that: The preprocessing is performed on the plurality of original observed images respectively, wherein the preprocessing comprises: Performing background image and flat field image correction on each of the plurality of original observation images; and Remove cosmic rays from each original observed image.

4. The method for identifying fast-moving targets according to claim 1, characterized in that: The astronomical position calibration is performed on the pre-processed multiple original observation images respectively, including: The original observation images are calibrated for astronomical positions through the world coordinate system to determine the specific positions on the celestial sphere mapped to the pixels on the original observation images.

5. The method for identifying fast-moving targets according to claim 1 or 4, characterized in that: The step of merging and superimposing the multiple original observation images after color assignment to obtain the target observation image includes: Based on the astronomical position, multiple original observation images with color assignment in a series of time-series observation images are merged and superimposed to obtain a single target observation image.

6. The method for identifying fast-moving targets according to claim 1, characterized in that: The identifying of the fast-moving target based on the dynamic trajectory in the target observation image includes: One or more dynamic tracks formed by targets of different colors are determined in the target observation image.

7. The method for identifying fast-moving targets according to claim 1 or 6, characterized in that: The step of identifying a fast-moving target based on the dynamic trajectory in the target observation image further includes: When the dynamic trajectory is a straight line, determining the straight-line motion trajectory as a spatial fast-moving target trajectory; The fast-moving target is identified according to the spatial fast-moving target trajectory.

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