Recognition of partially occluded objects

A computer vision system for the recognition of real world image is developed and reported. The system is capable of identifying multiple overlapped objects in a scene without stringent restrictions on their size, shape and orientation. An object shape is identified by the system through the detection of selected discrete feature segments in the contour code instead of attempting to search for a complete boundary. Consequently, an object that is partially occluded can still be recognized with its remaining unmasked portion. Extraction of salient features from an unknown geometry is performed using the nonlinear elastic matching technique. This algorithm is insensitive to sizing and distortions of the feature segments, hence reducing the problems caused by the error imposed during the image capturing process. A multilayer artificial neural network is used to provide the final identification of an unknown object based on the extracted features. A case study on the recognition of handtools with different surface reflectiveness is presented as an example. Possible improvements in the performance of the system are discussed. >

[1]  Zhi-Qiang Liu,et al.  On the minimum number of templates required for shift, rotation and size invariant pattern recognition , 1988, Pattern Recognit..

[2]  King-Sun Fu,et al.  Shape Discrimination Using Fourier Descriptors , 1977, IEEE Trans. Syst. Man Cybern..

[3]  H. Sakoe,et al.  Two-level DP-matching--A dynamic programming-based pattern matching algorithm for connected word recognition , 1979 .

[4]  Min-Hong Han,et al.  The use of maximum curvature points for the recognition of partially occluded objects , 1990, Pattern Recognit..

[5]  Laveen N. Kanal,et al.  Patterns in pattern recognition: 1968-1974 , 1974, IEEE Trans. Inf. Theory.

[6]  Ming-Kuei Hu,et al.  Visual pattern recognition by moment invariants , 1962, IRE Trans. Inf. Theory.

[7]  Terry Caelli,et al.  Fast edge-only matching techniques for robot pattern recognition , 1987 .

[8]  M. H. Chan,et al.  Recognition of partially occluded two-dimensional objects , 1987 .

[9]  W. A. Perkins,et al.  A Model-Based Vision System for Industrial Parts , 1978, IEEE Transactions on Computers.

[10]  Jake K. Aggarwal,et al.  Computer Recognition of Partial Views of Curved Objects , 1977, IEEE Transactions on Computers.

[11]  Dana H. Ballard,et al.  Generalizing the Hough transform to detect arbitrary shapes , 1981, Pattern Recognit..

[12]  Mandyam D. Srinath,et al.  Partial Shape Classification Using Contour Matching in Distance Transformation , 1990, IEEE Trans. Pattern Anal. Mach. Intell..

[13]  Richard A. Volz,et al.  Recognizing Partially Occluded Parts , 1985, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[14]  Terry Caelli,et al.  Invariant pattern recognition using multiple filter image representations , 1989, Comput. Vis. Graph. Image Process..

[15]  Robert B. McGhee,et al.  Aircraft Identification by Moment Invariants , 1977, IEEE Transactions on Computers.

[16]  Yoh-Han Pao,et al.  Adaptive pattern recognition and neural networks , 1989 .