Imaging Science and Photochemistry ›› 2016, Vol. 34 ›› Issue (6): 541-551.DOI: 10.7517/j.issn.1674-0475.2016.06.541

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Application of Image Displacement Compensation Based on Feature Block Matching for Medical Injection

RUAN Feng, ZHANG Hui, LI Xuanlun, LI Ruoyun   

  1. College of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410004, Hunan, P. R. China
  • Received:2016-06-12 Online:2016-11-15 Published:2016-11-15

Abstract:

The sequence images captured by the intelligent light inspection machine had the displacement deviation caused by mechanical vibration or tracking asynchronization, which affected the subsequent foreign body segmentation and extraction. To obtain the motion vectors to compensate for the image displacement, the method of feature point detection and block matching is adopted. Firstly, the reference frame was detected by FAST feature points, and used the non-maximal suppression,Hessian matrix,the entropy difference and distance constraint to select stable feature points. According to the location information of the feature points, the matching block were selected, of which the center was located by the feature points. Then, an improved horizontal direction search strategy(HHS) was used to match the current frame to find the best matching block. Finally, the motion parameters were obtained, and the motion vectors were obtained. Experimental results show that the real-time performance of this algorithm is 72 ms, much more faster than the 140 ms algorithm of ORB, and faster than the direct use of the original Hexagonal Search(HS) algorithm for block matching nearly 20%. The accuracy is higher than the feature point matching algorithms. Our algorithm overcomed these problems: 1. the traditional feature point matching could produce a large spatial deviation error matching; 2. the traditional block matching need to preprocess the static background blocks; 3. it is difficult to meet the needs of real time for single feature point matching or block matching. Considering the speed and precision, this algorithm can rapidly compensate the displacement deviation in the image of the bottle, and suppress the interference caused by the deviation of the image displacement.

Key words: machine vision, foreign body detection robot, feature point detection, block matching, search strategy, motion compensation