APPEARANCE BASED SALIENT POINT DETECTION WITH INTRINSIC SCALE-FREQUENCY DESCRIPTOR

Recent object recognition methods propose to represent objects by collections of local appearance descriptors in sev eral interest points. For recognition, this representatio n is matched to image data. Interest points (candidates for matching) are usually selected from images in a purely bottom-up manner. However, in many situations, there is a limited number of objects to search for, and some information about object characteristics should be employed in the detection of salient points, to reduce the number of potential candidates. In this paper we propose a methodology for the selection of candidates with prior information of the object local appearance. Points are represented by a rotation and scale invariant descriptor, composed by the response of filters derived from Gabor functions, denoted as “intrinsic scale/frequency descriptor”. When compared to classical salient point detectors, like extremal points of laplacian operators at several scales, the proposed methodology is able to reduce the amount of canditates for matching by more than 60%. Since matching is a costly operation, this strategy will improve the efficiency of object recognition methods.

[1]  Andrew Zisserman,et al.  An Affine Invariant Salient Region Detector , 2004, ECCV.

[2]  Pietro Perona,et al.  Towards automatic discovery of object categories , 2000, Proceedings IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2000 (Cat. No.PR00662).

[3]  Alexandre Bernardino,et al.  Gabor Parameter Selection for Local Feature Detection , 2005, IbPRIA.

[4]  Bill Triggs,et al.  Detecting Keypoints with Stable Position, Orientation, and Scale under Illumination Changes , 2004, ECCV.

[5]  Cordelia Schmid,et al.  Local Grayvalue Invariants for Image Retrieval , 1997, IEEE Trans. Pattern Anal. Mach. Intell..

[6]  Alexandre Bernardino,et al.  A Real-Time Gabor Primal Sketch for Visual Attention , 2005, IbPRIA.

[7]  Leonidas J. Guibas,et al.  A metric for distributions with applications to image databases , 1998, Sixth International Conference on Computer Vision (IEEE Cat. No.98CH36271).

[8]  David G. Lowe,et al.  Object recognition from local scale-invariant features , 1999, Proceedings of the Seventh IEEE International Conference on Computer Vision.

[9]  Michael Brady,et al.  Saliency, Scale and Image Description , 2001, International Journal of Computer Vision.

[10]  Cordelia Schmid,et al.  An Affine Invariant Interest Point Detector , 2002, ECCV.

[11]  A. Martínez,et al.  The AR face databasae , 1998 .

[12]  Aleix M. Martinez,et al.  The AR face database , 1998 .