Authors:
María Flores
;
Marc Fabregat-Jaén
;
Juan Cabrera
;
Adrián Peidró
;
David Valiente
and
Luis Payá
Affiliation:
Engineering Research Institute of Elche (I3E), Miguel Hernández University, Avda. de la Universidad, s/, 03202, Elche, Alicante, Spain
Keyword(s):
Place Recognition, Equirectangular Images, Semantic Information, Bag of Visual Words.
Abstract:
Place recognition has a crucial relevance in some tasks of mobile robot navigation. For example, it is used for the detection of loop-closure or for estimating the position of a mobile robot along a route in a known environment. If place recognition is based on visual information, it can be approached as an image retrieval problem. The Bag of Visual Words technique can be used for image retrieval. Image retrieval is based on an image representation (for example, a vector) that contains relevant visual information. In this paper, two image signatures are proposed. Both are based on semantic and visual information. A bag of visual words is created for each semantic class. Local feature descriptors are classified according to the projection of their associated point on a segmented semantic map. On the one hand, the image signature is composed of a set of histograms where each cell encodes the frequency with which a visual word appears in the image. On the other hand, the image signature
is composed of a set of vectors where each cell encodes the sum of the cosine distance between the visual word and the nearest extracted features.
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