scholarly journals Lossless Location Coding for Image Feature Points

Author(s):  
Gyeongmin Choi ◽  
Hyunil Jung ◽  
Haekwang Kim
Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1839
Author(s):  
Yutong Zhang ◽  
Jianmei Song ◽  
Yan Ding ◽  
Yating Yuan ◽  
Hua-Liang Wei

Fisheye images with a far larger Field of View (FOV) have severe radial distortion, with the result that the associated image feature matching process cannot achieve the best performance if the traditional feature descriptors are used. To address this challenge, this paper reports a novel distorted Binary Robust Independent Elementary Feature (BRIEF) descriptor for fisheye images based on a spherical perspective model. Firstly, the 3D gray centroid of feature points is designed, and the position and direction of the feature points on the spherical image are described by a constructed feature point attitude matrix. Then, based on the attitude matrix of feature points, the coordinate mapping relationship between the BRIEF descriptor template and the fisheye image is established to realize the computation associated with the distorted BRIEF descriptor. Four experiments are provided to test and verify the invariance and matching performance of the proposed descriptor for a fisheye image. The experimental results show that the proposed descriptor works well for distortion invariance and can significantly improve the matching performance in fisheye images.


2014 ◽  
Vol 519-520 ◽  
pp. 577-580
Author(s):  
Shuai Yuan ◽  
Guo Yun Zhang ◽  
Jian Hui Wu ◽  
Long Yuan Guo

Fingerprint image feature extraction is a critical step to fingerprint recognition system, which studies topological structure, mathematical model and extraction algorithm of fingerprint feature. This paper presents system design and realization of feature extraction algorithm for fingerprint image. On the basis of fingerprint skeleton image, feature points including ending points, bifurcation points and singular points are extracted at first. Then false feature points are detected and eliminated by the violent changes of ambient orientation field. True feature points are marked at last. Test result shows that the method presented has good accuracy, quick speed and strong robustness for realtime application.


2005 ◽  
Vol 1 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Hao Zhang ◽  
Zhan-hua Huang ◽  
Dao-ying Yu

Author(s):  
Sani M. Abdullahi ◽  
Hongxia Wang ◽  
Asad Malik

Fingerprint minutiae is the unique representation of fingerprint image feature points as terminations and bifurcations. Therefore, generating a hash signature from these feature points will unarguably meet the desired properties of a robust hash signature and which will accurately fit in for fingerprint image content authentication purposes. This article proposes a novel minutiae and shape context-based fingerprint image hashing scheme. Fingerprint image minutiae points were extracted by incorporating their orientation and descriptors, then embedded into the shape context-based descriptors in order to generate a unique, compact, and robust hash signature. The robustness of the proposed scheme is determined by performing content preserving attacks, including noise addition, blurring and geometric distribution. Efficient results were achieved from the given attacks. Also, a series of evaluations on the performance comparison between the proposed and other state-of-art schemes has proven the approach to be robust and secure, by yielding a better result.


2012 ◽  
Vol 27 (1) ◽  
pp. 125-129
Author(s):  
丁南南 DING Nan-nan ◽  
刘艳滢 LIU Yan-ying ◽  
朱明 ZHU Ming

2018 ◽  
Vol 6 (4) ◽  
Author(s):  
Ren-Jung Chang ◽  
Jun-Fu Liu

A three-dimensional (3D)-virtual calibration and visual servo are implemented for augmented reality (AR)-assisted peg-in-hole microassembly operations. By employing 3D model and ray casting, the 3D coordinates on virtual mating rod correspondent to the two-dimensional (2D) virtual image points are extracted. The detecting and tracking of image feature points for calibration is carried out by the proposed algorithm of regional template matching (TM) and scanning with edge fitting (RTM-SEF). For achieving subpixel error between the feature points in real and virtual images, a coarse-fine virtual calibration method is proposed. In regard to the image viewed by the real and virtual cameras, a calibrated virtual camera is utilized to track the mating rod. A visual servo control law including coarse and fine tuning is proposed to ensure sub-pixel error between the most important feature point in the real and virtual images. The AR technology is mainly employed in the alignment between micropeg and mating hole for inserting a micropeg of diameter 80 μm with length 1–1.4 mm into a mating rod with 100 μm hole.


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