Method and system for restoring image after fixed-frequency shooting of railway wagon line-scan digital camera
By adding an area scan camera to the TFDS system for visual speed measurement and adjusting the scanning frequency of the line scan camera, the image distortion problem in situations such as vehicle speed change, stopping, and reversing was solved, and accurate identification of key components of railway freight cars was achieved.
Patent Information
- Application Number
- CN202511717389.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-24
AI Technical Summary
In the existing TFDS system, when wheel sensors experience speed changes, stops, or reversing, they cannot acquire image information in real time, resulting in geometric distortion of the images captured by the line scan camera and affecting the accuracy of identifying key components of railway freight cars.
Add an area scan camera to calculate the speed of railway freight cars using visual speed measurement methods. Adjust the scanning frequency of the line scan camera to a fixed frequency. Use the ratio of the shooting frequencies of the area scan camera and the line scan camera to perform equally spaced sampling to achieve unstretched and compressed image restoration.
It achieves image geometric distortion correction under complex train passing conditions, improves the recognition accuracy of key components of railway freight cars, and does not require additional physical sensors, thus possessing high real-time performance and accuracy.
Smart Images
Figure CN121567973A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of image restoration, specifically to a method and system for restoring images captured by a railway freight car line array camera at a fixed frequency. Background Technology
[0002] In the existing TFDS freight car fault trackside image detection system, high-speed linear scan cameras are installed in the middle and on both sides of the track to continuously scan the freight car as it passes, generating high-definition images of the vehicle's bottom, sides, and bogies. These images are transmitted in real time via network to a remote "detection center," where professional inspectors analyze them on computer screens to determine whether critical components (such as brake beams, suspension components, couplers, and wheels) have faults such as breakage, missing parts, or deformation.
[0003] To avoid stretching and compression deformation of the image area captured by the line scan camera, the scanning frequency of the line scan camera needs to be synchronized with the speed of the vehicle passing through the image area. Current speed measurement methods use multiple wheel sensors at known distances to obtain the wheel travel time, thereby calculating the train speed. However, when there are changes in speed, stopping, or reversing between wheel sensors, the system cannot obtain relevant information in real time, leading to geometric distortion of the captured images (train deceleration → camera frequency too high → image stretched; train acceleration → camera frequency too low → image compressed), affecting subsequent automatic identification and manual analysis of key components such as wheels, undercarriage, and sides.
[0004] Therefore, it is particularly important to provide a method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars. Summary of the Invention
[0005] This invention addresses the problem that when wheel sensors experience speed changes, stops, or reversing, they cannot acquire image information in real time, leading to geometric distortion in the captured images and low accuracy in identifying key components of railway freight cars. It proposes a method and system for restoring images captured by a line-scan camera on railway freight cars at a fixed frequency.
[0006] The specific process of a method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars is as follows:
[0007] S1, based on the maximum speed of freight cars on the installed railway line. Obtain the shooting frequency of the line scan camera. ;
[0008] S2. The upper limit frequency supported by the area scan camera is used as the shooting frequency of the area scan camera. ;
[0009] S3. After the railway freight car passes the remote wheel sensor, the area scan camera captures images at a certain frequency. Start fixed-frequency shooting; the line scan camera operates at a shooting frequency. Start fixed-frequency shooting; the shooting start time is the same for both area scan cameras and line scan cameras;
[0010] Based on the shooting frequency of the area scan camera Shooting frequency of line scan camera Obtain the row number of the line scan camera corresponding to the area scan image number captured by the area scan camera;
[0011] S4. Calculate the speed of railway freight cars based on area array images captured by an area array camera. ;
[0012] S5, based on the speed of railway freight cars Calculate the unstretched compression frequency of a linear scan camera. ;
[0013] S6. Calculate the unstretched compression frequency of the linear scan camera. The shooting frequency of the line scan camera obtained from S1 frequency ratio ;
[0014] S7, Based on ratio The line lines captured by the line scan camera are sampled at equal intervals to obtain all sampled line lines;
[0015] S8. Save all sampled lines in the specified format image file according to the set image width, following the sampling order from front to back.
[0016] Preferably, S1 is based on the maximum speed of freight cars on the railway line. Obtain the shooting frequency of the line scan camera. The specific process is as follows:
[0017]
[0018] in, This represents the ratio of distance to the number of pixels in the captured image, where the distance is the actual distance between the line scan camera and the shooting location.
[0019] The value is 1mm / px; The unit is mm / px; The unit is Hz; The unit is m / s.
[0020] Preferably, in S3, after the railway freight car passes the remote wheel sensor, the area array camera captures images at a certain frequency. Start fixed-frequency shooting; the line scan camera operates at a shooting frequency. Start fixed-frequency shooting; the shooting start time is the same for both area scan cameras and line scan cameras;
[0021] Based on the shooting frequency of the area scan camera Shooting frequency of line scan camera The process involves obtaining the row line number captured by the line scan camera corresponding to the area scan image number captured by the area scan camera; the specific process is as follows:
[0022] Each area scan image corresponds to a line scan camera. The row lines correspond to the area array image of camera 1 to the area array image of camera 1. Line 1, area 2 image corresponds to the image captured by the line scan camera. Number Line 3, area array image corresponding to the image captured by the line array camera. Number Line number is obtained by repeating this process to obtain the line number captured by the line scan camera corresponding to the number of all area scan images.
[0023] Preferably, in step S4, the speed of the railway freight car is calculated based on the area array image captured by the area array camera. ; indicates as:
[0024]
[0025] in, Pixel offset of feature points or specific components in adjacent area array images captured by an area array camera;
[0026] This represents the ratio of distance to the number of pixels in the captured image, where the distance is the actual distance between the area scan camera and the shooting location.
[0027] speed The unit is mm / s; The unit is Hz; The unit is mm / px, where px represents the unit pixel.
[0028] Preferably, in S5, the speed of the railway freight car is used as the basis for the calculation. Calculate the unstretched compression frequency of a linear scan camera. ; indicates as:
[0029] .
[0030] Preferably, in S7, the ratio is used as the basis for... The line lines captured by the line scan camera are sampled at equal intervals to obtain all sampled line lines; the specific process is as follows:
[0031] S71. Determine the speed of the railway freight car corresponding to the No. 1 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed.
[0032] S72. Determine the speed of the railway freight car corresponding to the No. 2 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed.
[0033] S73. Determine the speed of the railway freight car corresponding to the No. 3 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed.
[0034] S74. Continue in this manner until the speed of the railway freight car corresponding to all area array images has been determined, and all sampled travel lines are obtained.
[0035] Preferably, in step S71, the speed of the railway freight car corresponding to the No. 1 area array image is determined, and based on the speed, it is determined whether to perform equally spaced sampling of the line lines captured by the line array camera; the specific process is as follows:
[0036] If the speed of the railway freight car corresponding to the image of array 1 is... Positive numbers, based on ratios For line scan cameras at shooting frequency The first to be photographed The line is sampled at equal intervals to obtain the sampled line;
[0037] If the speed of the railway freight car corresponding to the image of array 1 is... The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled.
[0038] If the speed of the railway freight car corresponding to the image of array 1 is... A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. If a freight train reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured line of sight was discarded;
[0039] in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
[0040] Preferably, in step S72, the speed of the railway freight car corresponding to the second area array image is determined, and based on the speed, it is determined whether to perform equally spaced sampling of the line lines captured by the line array camera; the specific process is as follows:
[0041] If the speed of the railway freight car corresponding to the image of area array 2 Positive numbers, based on ratios For line scan cameras at shooting frequency Filmed Number The line is sampled at equal intervals to obtain the sampled line;
[0042] If the speed of the railway freight car corresponding to the image of array 2 is... The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled.
[0043] If the speed of the railway freight car corresponding to the image of array 2 is... A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. If a freight train reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured line of sight was discarded;
[0044] in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
[0045] Preferably, in step S73, the speed of the railway freight car corresponding to the No. 3 area array image is determined, and based on the speed, it is determined whether to perform equally spaced sampling of the line lines captured by the line array camera; the specific process is as follows:
[0046] If the speed of the railway freight car corresponding to the image of area array 3 is... Positive numbers, based on ratios For line scan cameras at shooting frequency Filmed Number The line is sampled at equal intervals to obtain the sampled line;
[0047] If the speed of the railway freight car corresponding to the image of area array 3 is... The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled.
[0048] If the speed of the railway freight car corresponding to the image of area array 3 is... A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. If a freight train reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured line of sight was discarded;
[0049] in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
[0050] A system for restoring images after fixed-frequency shooting by a line scan camera on railway freight cars is used to perform a method for restoring images after fixed-frequency shooting by a line scan camera on railway freight cars.
[0051] The beneficial effects of this invention are as follows:
[0052] This invention relates to a method for restoring images captured by a line-scan camera on railway freight cars at a fixed frequency. It addresses the problem in existing TFDS systems where the system cannot detect changes in speed, stopping, or reversing between adjacent wheel sensors, leading to image distortion due to missynchronization of the line-scan camera's scanning frequency and resulting in stretched / compressed geometric distortion in the captured images. This invention adds an area-scan camera to the existing TFDS system, performing visual speed measurement through analysis of consecutive frames. This addresses complex freight car passing situations, including combinations of speed changes, stopping, and reversing. By adjusting the line-scan camera's scanning frequency to a fixed frequency and using relevant restoration methods, the method accurately restores the freight car image, solving the image geometric distortion problem and improving the accuracy of identifying key components of railway freight cars.
[0053] This invention adds an area array camera for visual speed measurement, directly measuring speed through non-contact image methods, resulting in higher real-time performance and more accurate speed measurement; this invention can handle complex vehicle passage situations for trucks, including combinations of situations such as gear shifting, stopping, and reversing.
[0054] This invention requires no additional physical sensors, is wear-free, and has no blind spots. Its more precise real-time speed ensures more realistic imaging results from the line scan camera. It provides accurate and reliable image data support for railway transportation safety monitoring and freight car condition detection, improving the accuracy of identifying key components of railway freight cars. This invention is applicable to different types of railway freight cars and complex environments, and has broad application prospects. Attached Figure Description
[0055] Figure 1 This is a flowchart of the present invention;
[0056] Figure 2 This is a diagram illustrating camera synchronization and fixed-frequency shooting. Detailed Implementation
[0057] Specific Implementation Method 1: The specific process of this implementation method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars is as follows:
[0058] S1, based on the maximum speed of freight cars on the installed railway line. Obtain the shooting frequency of the line scan camera. ;
[0059] S2. The upper limit frequency supported by the area scan camera is used as the shooting frequency of the area scan camera. ;
[0060] S3. After the railway freight car passes the remote wheel sensor, the area scan camera captures images at a certain frequency. Start fixed-frequency shooting; the line scan camera operates at a shooting frequency. Start fixed-frequency shooting; the shooting start time is the same for both area scan cameras and line scan cameras;
[0061] Based on the shooting frequency of the area scan camera Shooting frequency of line scan camera Obtain the row number of the line scan camera corresponding to the area scan image number captured by the area scan camera;
[0062] S4. Calculate the speed of railway freight cars based on area array images captured by an area array camera. ;
[0063] S5, based on the speed of railway freight cars Calculate the unstretched compression frequency of a linear scan camera. ;
[0064] S6. Calculate the unstretched compression frequency of the linear scan camera. The shooting frequency of the line scan camera obtained from S1 frequency ratio ;
[0065] S7, Based on ratio The line lines captured by the line scan camera are sampled at equal intervals to obtain all sampled line lines;
[0066] S8. Save all sampled lines in the order of sampling from front to back as image files in the specified format (jpg or png) according to the set image width.
[0067] A method for restoring images captured by a line-scan camera on railway freight cars at a fixed frequency is based on existing TFDS equipment. One or more area-scan cameras are added and installed near the original line-scan camera positions to continuously capture images of the train's bottom or sides at a fixed frequency. In consecutive image frames, unique feature points (such as bolts, welds, and textures) or specific components (such as wheel edges) are identified and tracked. An algorithm calculates the pixel displacement of these feature points on the image plane. The line-scan camera in the TFDS equipment is adjusted to capture images at a fixed frequency, which must meet the maximum speed of freight cars passing through the track.
[0068] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that S1 is based on the maximum speed of freight cars on the railway line. Obtain the shooting frequency of the line scan camera. The specific process is as follows:
[0069]
[0070] in, This indicates the ratio of distance to the number of pixels in the captured image, depending on the installation location of the line scan camera. The distance is the actual distance between the line scan camera and the shooting location.
[0071] The value is 1mm / px; The unit is mm / px; The unit is Hz; The unit is m / s.
[0072] The other steps and parameters are the same as in Specific Implementation Method 1.
[0073] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that, in S3, after the railway freight car passes the remote wheel sensor, the area array camera captures images at a certain frequency. Start fixed-frequency shooting; the line scan camera operates at a shooting frequency. Start fixed-frequency shooting; the shooting start time is the same for both area scan cameras and line scan cameras;
[0074] Based on the shooting frequency of the area scan camera Shooting frequency of line scan camera The process involves obtaining the row line number captured by the line scan camera corresponding to the area scan image number captured by the area scan camera; the specific process is as follows:
[0075] Each area scan image corresponds to a line scan camera. The row lines correspond to the area array image of camera 1 to the area array image of camera 1. Line 1, area 2 image corresponds to the image captured by the line scan camera. Number Line 3, area array image corresponding to the image captured by the line array camera. Number Line number is obtained by repeating this process to obtain the line number captured by the line scan camera corresponding to the number of all area scan images.
[0076] Other steps and parameters are the same as in specific implementation method one or two.
[0077] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that, in S4, the speed of the railway freight car is calculated based on the area array images captured by the area array camera. ; indicates as:
[0078]
[0079] in, Pixel offset of feature points (such as bolts, welds, textures) or specific parts (such as wheel edges) in adjacent area array images captured by an area array camera;
[0080] This indicates the ratio of distance to the number of pixels in the captured image, depending on the installation location of the area scan camera. The distance is the actual distance between the area scan camera and the shooting location.
[0081] speed The unit is mm / s; The unit is Hz; The unit is mm / px, where px represents the unit pixel;
[0082] It is obtained by calibrating after the camera is installed. Typically, a checkerboard pattern is installed at the shooting position online, and an area scan camera is used to shoot the checkerboard pattern. The ratio between the actual size of the checkerboard pattern and the corresponding number of pixels in the image is calculated.
[0083] The higher the shooting frequency of the area array camera, the higher the accuracy of the calculated train speed in the time dimension.
[0084] The other steps and parameters are the same as those in one of the specific implementation methods one to three.
[0085] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that S5 is based on the speed of railway freight cars. Calculate the unstretched compression frequency of a linear scan camera. ; indicates as:
[0086] .
[0087] The other steps and parameters are the same as those in one of the specific implementation methods one to four.
[0088] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that, in S7, it is based on the ratio. The line lines captured by the line scan camera are sampled at equal intervals to obtain all sampled line lines; the specific process is as follows:
[0089] S71. Determine the speed of the railway freight car corresponding to the No. 1 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed.
[0090] S72. Determine the speed of the railway freight car corresponding to the No. 2 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed.
[0091] S73. Determine the speed of the railway freight car corresponding to the No. 3 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed.
[0092] S74. Continue in this manner until the speed of the railway freight car corresponding to all area array images has been determined, and all sampled travel lines are obtained.
[0093] The other steps and parameters are the same as those in one of the specific implementation methods one to five.
[0094] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that, in S71, the speed of the railway freight car corresponding to the No. 1 area array image is determined, and based on the speed, it is determined whether to perform equally spaced sampling of the line lines captured by the line array camera; the specific process is as follows:
[0095] If the speed of the railway freight car corresponding to the image of array 1 Positive numbers, based on ratios For line scan cameras at shooting frequency The first to be photographed The line is sampled at equal intervals to obtain the sampled line;
[0096] If the speed of the railway freight car corresponding to the image of array 1 The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled.
[0097] If the speed of the railway freight car corresponding to the image of array 1 A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. If a freight train reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured train line is discarded (after returning to the position before reversing, the speed of the railway freight car is determined again);
[0098] in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
[0099] The other steps and parameters are the same as those in one of the specific implementation methods one to six.
[0100] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One through Seven in that, in S72, the speed of the railway freight car corresponding to the No. 2 area array image is determined, and based on the speed, it is determined whether to perform equally spaced sampling of the line lines captured by the line array camera; the specific process is as follows:
[0101] If the speed of the railway freight car corresponding to the image of area array 2 Positive numbers, based on ratios For line scan cameras at shooting frequency Filmed Number The line is sampled at equal intervals to obtain the sampled line;
[0102] If the speed of the railway freight car corresponding to the image of area array 2 The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled.
[0103] If the speed of the railway freight car corresponding to the image of area array 2 A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. If a freight train reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured train line is discarded (after returning to the position before reversing, the speed of the railway freight car is determined again);
[0104] in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
[0105] The other steps and parameters are the same as those in any of the specific implementation methods one to seven.
[0106] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One through Eight in that, in S73, the speed of the railway freight car corresponding to the No. 3 area array image is determined, and based on the speed, it is determined whether to perform equally spaced sampling of the line lines captured by the line array camera; the specific process is as follows:
[0107] If the speed of the railway freight car corresponding to the image of area array 3 is... Positive numbers, based on ratios For line scan cameras at shooting frequency Filmed Number The line is sampled at equal intervals to obtain the sampled line;
[0108] If the speed of the railway freight car corresponding to the image of area array 3 is... The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled.
[0109] If the speed of the railway freight car corresponding to the image of area array 3 is... A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. If a freight train reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured train line is discarded (after returning to the position before reversing, the speed of the railway freight car is determined again);
[0110] in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
[0111] The other steps and parameters are the same as those in one of the specific implementation methods one to eight.
[0112] By using the fixed shooting frequencies of line scan and area scan cameras, a corresponding relationship can be obtained. For example, if a line scan camera scans 1000 lines per second and an area scan camera takes 10 images, then one area scan image corresponds to 100 lines. After calculating the speed from this area scan image, the image-undistorted shooting frequency can be calculated. This frequency is definitely lower than the fixed shooting frequency of the current line scan camera. Therefore, based on the ratio of these two frequencies, these 100 lines need to be sampled at equal intervals. The sampled data needs to be retained. The process of calculating the speed from the area scan image and sampling the line scan lines is repeated. All the sampled lines are arranged in order and stored from front to back according to the image width.
[0113] The default image width for freight train images is 1400px. Therefore, after the entire train passes, all the line scan cameras that have taken pictures of the train's path will store one image every 1400 pixels in sequence until the end.
[0114] Each line has a fixed width of 1 pixel, while the height depends on whether the line scan camera is 1K or 2K, with heights of 1024 and 2048 pixels respectively. This way, storing 1400 lines sequentially results in an image. or size;
[0115] The aforementioned fixed-frequency shooting method can be combined with the existing TFDS variable-frequency shooting method. When railway freight cars are passing normally and the speed is relatively stable, the wheel sensor speed measurement can be used to synchronously shoot with the line array camera using variable-frequency shooting. When the train enters a deceleration phase, the fixed-frequency shooting method can be used to restore the image. This method offers greater flexibility and faster processing speed.
[0116] A line-scan camera, fixed beside the track, continuously captures images of passing freight cars at a constant frequency. If the area scan image calculates the train speed to be 0, it indicates the train is currently stationary. The line-scan camera continues scanning, consistently capturing the train's position at that fixed point, and discards the scanned lines from that stationary period. If the train reverses after stopping, the area scan camera calculates a negative speed. In this case, the line scan is capturing a previously captured area, which is considered a duplicate and is discarded. If the train continues moving forward after reversing, the line-scan camera will scan a section of the train body that was just reversed through, which is also discarded. Data is only retained after the freight car has moved back to its initial stopping position.
[0117] Specific Implementation Method 10: This implementation method is a system for restoring images after fixed-frequency shooting by a line array camera on railway freight cars. The system is used to execute a method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars.
[0118] This invention may have other embodiments. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.
Claims
1. A method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars, characterized in that: The specific process of the method is as follows: S1, based on the maximum speed of freight cars on the installed railway line. Obtain the shooting frequency of the line scan camera. ; S2. The upper limit frequency supported by the area scan camera is used as the shooting frequency of the area scan camera. ; S3. After the railway freight car passes the remote wheel sensor, the area scan camera captures images at a certain frequency. Start fixed-frequency shooting; the line scan camera operates at a shooting frequency. Start fixed-frequency shooting; the shooting start time is the same for both area scan cameras and line scan cameras; Based on the shooting frequency of the area scan camera Shooting frequency of line scan camera Obtain the row number of the line scan camera corresponding to the area scan image number captured by the area scan camera; S4. Calculate the speed of railway freight cars based on area array images captured by an area array camera. ; S5, based on the speed of railway freight cars Calculate the unstretched compression frequency of a linear scan camera. ; S6. Calculate the unstretched compression frequency of the linear scan camera. The shooting frequency of the line scan camera obtained from S1 frequency ratio ; S7, Based on ratio The line lines captured by the line scan camera are sampled at equal intervals to obtain all sampled line lines; S8. Save all sampled lines in the specified format image file according to the set image width, following the sampling order from front to back.
2. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 1, characterized in that: S1 is based on the maximum speed of freight cars on the railway line. Obtain the shooting frequency of the line scan camera. The specific process is as follows: in, This represents the ratio of distance to the number of pixels in the captured image, where the distance is the actual distance between the line scan camera and the shooting location. The value is 1mm / px, where px represents the unit pixel; The unit is mm / px; The unit is Hz; The unit is m / s.
3. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 2, characterized in that: In S3, after the railway freight car passes the remote wheel sensor, the area array camera captures images at a certain frequency. Start fixed-frequency shooting; the line scan camera operates at a shooting frequency. Start fixed-frequency shooting; the shooting start time is the same for both area scan cameras and line scan cameras; Based on the shooting frequency of the area scan camera Shooting frequency of line scan camera The process involves obtaining the row line number captured by the line scan camera corresponding to the area scan image number captured by the area scan camera; the specific process is as follows: Each area scan image corresponds to a line scan camera. The row lines correspond to the area array image of camera 1 to the area array image of camera 1. Line 1, area 2 image corresponds to the image captured by the line scan camera. Number Line 3, area array image corresponding to the image captured by the line array camera. Number Line number is obtained by repeating this process to obtain the line number captured by the line scan camera corresponding to the number of all area scan images.
4. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 3, characterized in that: In step S4, the speed of the railway freight car is calculated based on the area array images captured by the area array camera. ; indicates as: in, Pixel offset of feature points or specific components in adjacent area array images captured by an area array camera; This represents the ratio of distance to the number of pixels in the captured image, where the distance is the actual distance between the area scan camera and the shooting location. speed The unit is mm / s; The unit is Hz; The unit is mm / px.
5. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 4, characterized in that: The S5 is based on the speed of railway freight cars. Calculate the unstretched compression frequency of a linear scan camera. ; indicates as: 。 6. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 5, characterized in that: The ratio-based S7 The line lines captured by the line scan camera are sampled at equal intervals to obtain all sampled line lines; The specific process is as follows: S71. Determine the speed of the railway freight car corresponding to the No. 1 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed. S72. Determine the speed of the railway freight car corresponding to the No. 2 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed. S73. Determine the speed of the railway freight car corresponding to the No. 3 area array image, and determine whether to perform equal-interval sampling on the line lines captured by the line array camera based on the speed. S74. Continue in this manner until the speed of the railway freight car corresponding to all area array images has been determined, and all sampled travel lines are obtained.
7. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 6, characterized in that: In S71, the speed of the railway freight car corresponding to the No. 1 area array image is determined, and based on the speed, it is determined whether to perform equal-interval sampling of the line lines captured by the line array camera. The specific process is as follows: If the speed of the railway freight car corresponding to the image of array 1 Positive numbers, based on ratios For line scan cameras at shooting frequency The first to be photographed The line is sampled at equal intervals to obtain the sampled line; If the speed of the railway freight car corresponding to the image of array 1 The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled. If the speed of the railway freight car corresponding to the image of array 1 A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. ; If the railway freight car reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured line of sight was discarded; in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
8. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 7, characterized in that: In S72, the speed of the railway freight car corresponding to the No. 2 area array image is determined, and based on the speed, it is determined whether to perform equal-interval sampling of the line lines captured by the line array camera. The specific process is as follows: If the speed of the railway freight car corresponding to the image of array 2 is... Positive numbers, based on ratios For line scan cameras at shooting frequency Filmed Number The line is sampled at equal intervals to obtain the sampled line; If the speed of the railway freight car corresponding to the image of array 2 is... The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled. If the speed of the railway freight car corresponding to the image of array 2 is... A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. ; If the railway freight car reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured line of sight was discarded; in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
9. The method for restoring images after fixed-frequency shooting by a line array camera on railway freight cars according to claim 8, characterized in that: In S73, the speed of the railway freight car corresponding to the No. 3 area array image is determined, and based on the speed, it is determined whether to perform equal-interval sampling of the line lines captured by the line array camera. The specific process is as follows: If the speed of the railway freight car corresponding to the image of area array 3 is... Positive numbers, based on ratios For line scan cameras at shooting frequency Filmed Number The line is sampled at equal intervals to obtain the sampled line; If the speed of the railway freight car corresponding to the image of area array 3 is... The speed of the railway freight car is set to 0. The corresponding line scan camera uses a shooting frequency The captured lines are discarded and not sampled. If the speed of the railway freight car corresponding to the image of area array 3 is... A negative value indicates that the railway freight car is reversing, reducing its speed. The corresponding line scan camera uses a shooting frequency The captured train tracks are discarded, no sampling is performed, and the reversing distance of the railway freight cars is calculated using calculus. ; If the railway freight car reverses and then moves forward again, the distance it travels will also be the same. The time indicates that the train has returned to its previous position before reversing. The corresponding line scan camera captures images at a specific frequency during the process of moving forward and returning to the previous position. The captured line of sight was discarded; in, The time interval is used to calculate the velocity using adjacent area scan cameras. Values .
10. A system for restoring images after fixed-frequency shooting by a linear array camera on railway freight cars, characterized in that: The system is used to perform a method for restoring images after fixed-frequency shooting by a line array camera for railway freight cars, as described in any one of claims 1 to 9.