scholarly journals A Novel Frequency Domain Iterative Image Registration Algorithm Based on Local Region Extraction

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xiujie Qu ◽  
Haili Huo ◽  
Sitong Lian ◽  
Fei Zhao
Keyword(s):  
High Speed ◽  
Large Angle ◽  
Correlation Method ◽  
Target Position ◽  
Local Region ◽  
Phase Correlation ◽  
Geometric Distortion ◽  
Speeded Up Robust Features ◽  
Correlation Algorithm ◽  
Region Extraction

Because of the differences of imaging time, position between sensor and target position, scaling, rotation, translation, and other transformations between the series of images will be generated by the imaging system. The conventional phase correlation algorithm has been widely applied because of its advantages of high speed, precision, and weak influence of the geometric distortion when computing these changing parameters. However, when the scaling factor and the rotation angle are too large, it is difficult to use the conventional phase correlation method for high precision registration. To solve this problem, this paper presents a novel method, which combines the speeded up robust features algorithm and the phase correlation method under the log polar. Through local region extraction and reusing a two-step iterative phase correlation algorithm, this method avoids excessive computation and the demand of characteristics of the image and effectively improves the accuracy of registration. A plurality of visible light image simulation verifies that this is a fast, accurate, and robust algorithm, even when the image has large angle rotation and large multiple scaling.

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

High-speed digital-image correlation method

2009 ◽  
Vol 34 (13) ◽  
pp. 1955 ◽  
Author(s):  
Min Wang ◽  
Hao Wang ◽  
Yuwan Cen
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Correlation Method ◽  
Image Correlation ◽  
Digital Image Correlation Method

scholarly journals Research on Remote Sensing Image Matching with Special Texture Background

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1380
Author(s):  
Sen Wang ◽  
Xiaoming Sun ◽  
Pengfei Liu ◽  
Kaige Xu ◽  
Weifeng Zhang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Remote Sensing Image ◽  
Geometric Distortion ◽  
Reference Image ◽  
Remote Sensing Images ◽  
Scale Invariant ◽  
Sift Algorithm ◽  
Speeded Up Robust Features ◽  
Adaptive Quantization ◽  
Texture Background

The purpose of image registration is to find the symmetry between the reference image and the image to be registered. In order to improve the registration effect of unmanned aerial vehicle (UAV) remote sensing imagery with a special texture background, this paper proposes an improved scale-invariant feature transform (SIFT) algorithm by combining image color and exposure information based on adaptive quantization strategy (AQCE-SIFT). By using the color and exposure information of the image, this method can enhance the contrast between the textures of the image with a special texture background, which allows easier feature extraction. The algorithm descriptor was constructed through an adaptive quantization strategy, so that remote sensing images with large geometric distortion or affine changes have a higher correct matching rate during registration. The experimental results showed that the AQCE-SIFT algorithm proposed in this paper was more reasonable in the distribution of the extracted feature points compared with the traditional SIFT algorithm. In the case of 0 degree, 30 degree, and 60 degree image geometric distortion, when the remote sensing image had a texture scarcity region, the number of matching points increased by 21.3%, 45.5%, and 28.6%, respectively and the correct matching rate increased by 0%, 6.0%, and 52.4%, respectively. When the remote sensing image had a large number of similar repetitive regions of texture, the number of matching points increased by 30.4%, 30.9%, and −11.1%, respectively and the correct matching rate increased by 1.2%, 0.8%, and 20.8% respectively. When processing remote sensing images with special texture backgrounds, the AQCE-SIFT algorithm also has more advantages than the existing common algorithms such as color SIFT (CSIFT), gradient location and orientation histogram (GLOH), and speeded-up robust features (SURF) in searching for the symmetry of features between images.

scholarly journals Cloud shadow speed sensor

2014 ◽  
Vol 7 (6) ◽  
pp. 1693-1700 ◽  
Author(s):  
V. Fung ◽  
J. L. Bosch ◽  
S. W. Roberts ◽  
J. Kleissl
Keyword(s):  
High Speed ◽  
Sensor Data ◽  
Motion Vectors ◽  
Speed Sensor ◽  
Correlation Algorithm ◽  
High Speed Data Acquisition ◽  
Economical System ◽  
High Speed Data ◽  
Mean Square Difference ◽  
Artificial Shading

Abstract. Changing cloud cover is a major source of solar radiation variability and poses challenges for the integration of solar energy. A compact and economical system is presented that measures cloud shadow motion vectors to estimate power plant ramp rates and provide short-term solar irradiance forecasts. The cloud shadow speed sensor (CSS) is constructed using an array of luminance sensors and a high-speed data acquisition system to resolve the progression of cloud passages across the sensor footprint. An embedded microcontroller acquires the sensor data and uses a cross-correlation algorithm to determine cloud shadow motion vectors. The CSS was validated against an artificial shading test apparatus, an alternative method of cloud motion detection from ground-measured irradiance (linear cloud edge, LCE), and a UC San Diego sky imager (USI). The CSS detected artificial shadow directions and speeds to within 15° and 6% accuracy, respectively. The CSS detected (real) cloud shadow directions and speeds with average weighted root-mean-square difference of 22° and 1.9 m s−1 when compared to USI and 33° and 1.5 m s−1 when compared to LCE results.

Phase Algorithm Integrating Direct-Correlation and Four-Step Phase-Shifting for Electronic Speckle Pattern Interferometry

2013 ◽  
Vol 448-453 ◽  
pp. 3696-3701
Author(s):  
Yan Bin He ◽  
Xin Zhong Li ◽  
Min Zhou
Keyword(s):  
High Speed ◽  
Speckle Pattern ◽  
Phase Shifting ◽  
Electronic Speckle Pattern Interferometry ◽  
High Speed Camera ◽  
Dynamic Measurements ◽  
High Quality ◽  
Correlation Algorithm ◽  
Phase Map

A phase-shifting algorithm, called a (4,4) algorithm, which takes four phase-shifting interferograms before a specimen is deformed and four interferograms after a specimen is deformed, is presented first. This method is most widely used for phase extraction. Its drawback limited it to be used in dynamic measurements. Also shown is an algorithm called a (4,1) algorithm that takes four phase-shifting interferograms before a specimen is deformed and one interferogram after a specimen is deformed. Because a high-speed camera can be used to record the dynamic interferogram of the specimen, this algorithm has the potential to retain the phase-shifting capability for ESPI in dynamic measurements. The quality of the phase map obtained using (4,1) algorithm is quite lower compared to using (4,4) algorithm. In order to obtain high-quality phase map in dynamic measurements, a direct-correlation algorithm was integrated with the (4,1) algorithm to form DC-(4,1) algorithm which is shown to improve significantly the quality of the phase maps. The theoretical and experimental aspects of this newly developed technique, which can extend ESPI to areas such as high-speed dynamic measurements, are examined in detail.

Tracking algorithm of snowboard target in intelligent system

2020 ◽  
pp. 1-9
Author(s):  
Zhipeng Li ◽  
Xiaolan Li ◽  
Ming Shi ◽  
Wenli Song ◽  
Guowei Zhao ◽  
...  
Keyword(s):  
Target Tracking ◽  
High Speed ◽  
Intelligent System ◽  
Mean Shift ◽  
Target Position ◽  
Tracking Algorithm ◽  
Tracking Accuracy ◽  
Mean Shift Algorithm ◽  
Target Track ◽  
The Mean

Snowboarding is a kind of sport that takes snowboarding as a tool, swivels and glides rapidly on the specified slope line, and completes all kinds of difficult actions in the air. Because the sport is in the state of high-speed movement, it is difficult to direct guidance during the sport, which is not conducive to athletes to find problems and correct them, so it is necessary to track the target track of snowboarding. The target tracking algorithm is the main solution to this task, but there are many problems in the existing target tracking algorithm that have not been solved, especially the target tracking accuracy in complex scenes is insufficient. Therefore, based on the advantages of the mean shift algorithm and Kalman algorithm, this paper proposes a better tracking algorithm for snowboard moving targets. In the method designed in this paper, in order to solve the problem, a multi-algorithm fusion target tracking algorithm is proposed. Firstly, the SIFT feature algorithm is used for rough matching to determine the fuzzy position of the target. Then, the good performance of the mean shift algorithm is used to further match the target position and determine the exact position of the target. Finally, the Kalman filtering algorithm is used to further improve the target tracking algorithm to solve the template trajectory prediction under occlusion and achieve the target trajectory tracking algorithm design of snowboarding.

The Research on Phantom-Bit Technology of Digital Phase Shifters for Satellite Tracking System of Phase Array

2014 ◽  
Vol 644-650 ◽  
pp. 4555-4558
Author(s):  
Chao Hai Li ◽  
Wen Xian Jiang ◽  
Guo Long Wang
Keyword(s):  
High Speed ◽  
Phased Array ◽  
Tracking System ◽  
Correlation Method ◽  
Digital Signal ◽  
Satellite Tracking ◽  
Phase Shifters ◽  
Phase Array ◽  
Satellite Platform ◽  
Beam Displacement

Phased array satellite platform self-tracking system is for the stability between the missiles and other high-speed movement of the platform and the relay satellite two-way information transmission needs to carry out the self-tracking technology research of onboard platform-dimensional active phased array satellite. The system uses a sub-array correlation method for accurate measurement of the angle of the satellite signal. Receiving array is divided into four 4 * 4 sub-array, each antenna signal combining unit 4 sub array for 4-way A / D to be converted, through down-conversion, filtering, extraction and other processes to get a digital baseband signal, the baseband digital signal processing is to extract the angle error information into digital beam orientation system for tracking filtering operation, thereby ensuring that the transceiver has been aligned with the satellite antenna beam direction. In this paper ,phantom-bit technology for satellite tracking system under the condition of minimum beam displacement is researched for satellite tracking system.

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