6,583 research outputs found
M\"obius Invariants of Shapes and Images
Identifying when different images are of the same object despite changes
caused by imaging technologies, or processes such as growth, has many
applications in fields such as computer vision and biological image analysis.
One approach to this problem is to identify the group of possible
transformations of the object and to find invariants to the action of that
group, meaning that the object has the same values of the invariants despite
the action of the group. In this paper we study the invariants of planar shapes
and images under the M\"obius group , which arises
in the conformal camera model of vision and may also correspond to neurological
aspects of vision, such as grouping of lines and circles. We survey properties
of invariants that are important in applications, and the known M\"obius
invariants, and then develop an algorithm by which shapes can be recognised
that is M\"obius- and reparametrization-invariant, numerically stable, and
robust to noise. We demonstrate the efficacy of this new invariant approach on
sets of curves, and then develop a M\"obius-invariant signature of grey-scale
images
Barcode Annotations for Medical Image Retrieval: A Preliminary Investigation
This paper proposes to generate and to use barcodes to annotate medical
images and/or their regions of interest such as organs, tumors and tissue
types. A multitude of efficient feature-based image retrieval methods already
exist that can assign a query image to a certain image class. Visual
annotations may help to increase the retrieval accuracy if combined with
existing feature-based classification paradigms. Whereas with annotations we
usually mean textual descriptions, in this paper barcode annotations are
proposed. In particular, Radon barcodes (RBC) are introduced. As well, local
binary patterns (LBP) and local Radon binary patterns (LRBP) are implemented as
barcodes. The IRMA x-ray dataset with 12,677 training images and 1,733 test
images is used to verify how barcodes could facilitate image retrieval.Comment: To be published in proceedings of The IEEE International Conference
on Image Processing (ICIP 2015), September 27-30, 2015, Quebec City, Canad
Image based visual servoing using bitangent points applied to planar shape alignment
We present visual servoing strategies based on bitangents for aligning planar shapes. In order to acquire bitangents we use convex-hull of a curve. Bitangent points are employed in the construction of a feature vector to be used in visual control. Experimental results obtained on a 7 DOF Mitsubishi PA10 robot, verifies the proposed method
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