@conference {14251,
	title = {Real-time shape retrieval for robotics using skip Tri-Grams},
	booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems, 2009. IROS 2009},
	year = {2009},
	month = {2009/10/10/15},
	pages = {4731 - 4738},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {The real time requirement is an additional constraint on many intelligent applications in robotics, such as shape recognition and retrieval using a mobile robot platform. In this paper, we present a scalable approach for efficiently retrieving closed contour shapes. The contour of an object is represented by piecewise linear segments. A skip Tri-Gram is obtained by selecting three segments in the clockwise order while allowing a constant number of segments to be {\~A}{\^A}{\textquestiondown}skipped{\~A}{\^A}{\textquestiondown} in between. The main idea is to use skip Tri-Grams of the segments to implicitly encode the distant dependency of the shape. All skip Tri-Grams are used for efficiently retrieving closed contour shapes without pairwise matching feature points from two shapes. The retrieval is at least an order of magnitude faster than other state-of-the-art algorithms. We score 80\% in the Bullseye retrieval test on the whole MPEG 7 shape dataset. We further test the algorithm using a mobile robot platform in an indoor environment. 8 objects are used for testing from different viewing directions, and we achieve 82\% accuracy.},
	keywords = {Bullseye retrieval test, Clocks, closed contour shape retrieval, Image retrieval, Image segmentation, Indexing, Information retrieval, Intelligent robots, Jacobian matrices, mobile robot, Mobile robots, MPEG 7 shape dataset, piecewise linear segments, Piecewise linear techniques, Real time systems, real-time shape retrieval, robot vision, SHAPE, shape recognition, shape representation, skip Tri-Grams, Testing},
	isbn = {978-1-4244-3803-7},
	doi = {10.1109/IROS.2009.5354738},
	author = {Li,Yi and Bitsakos,K. and Ferm{\"u}ller, Cornelia and Aloimonos, J.}
}
@article {16907,
	title = {Integration of local and global shape analysis for logo classification},
	journal = {Pattern Recognition Letters},
	volume = {23},
	year = {2002},
	month = {2002/10//},
	pages = {1449 - 1457},
	abstract = {A comparison is made of global and local methods for the shape analysis of logos in an image database. The qualities of the methods are judged by using the shape signatures to define a similarity metric on the logos. As representatives for the two classes of methods, we use the negative shape method which is based on local shape information and a wavelet-based method which makes use of global information. We apply both methods to images with different kinds of degradations and examine how a particular degradation highlights the strengths and shortcomings of each method. Finally, we use these results to develop a new adaptive weighting scheme which is based on the relative performances of the two methods. This scheme gives rise to a new method that is much more robust with respect to all degradations examined and works by automatically predicting if the negative shape or wavelet method is performing better.},
	keywords = {Image databases, Logos, shape recognition, shape representation, Symbol recognition},
	isbn = {0167-8655},
	doi = {10.1016/S0167-8655(02)00105-8},
	url = {http://www.sciencedirect.com/science/article/pii/S0167865502001058},
	author = {Neumann, Jan and Samet, Hanan and Soffer,Aya}
}
