Color Medical Image Edge Detection based on Higher Dimensional Fourier Transforms Applied in Diabetic Retinopathy Studies
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Date
2019-04-25
Authors
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Addis Ababa University
Abstract
Various edge detection techniques for color images that have been proposed in the last two
decades showed that color images contain 10% additional edge information as compared to their
gray scale counterparts. For color image edge detection, the traditional methods used for grayscale
images
are
usually
extended
and
applied
to
the
three-color
channels
separately.
This
leads
to
lose the intrinsic inter-correlation information embedded in color image components in
addition to computational complexity incurred. Efficient and accurate edge detection leads to
increased performance of subsequent image processing and analysis techniques including image
segmentation and quantification.
In this thesis, an edge detection algorithm has been proposed that treats color value triplets as
vectors based on higher dimensional algebra. A human perception-based color space has been
used due to its importance in color image edge detection. The trinion based algorithm has
provided an efficient method to represent the color information vectorally. Color edge features
are extracted based on a second order statistical technique using the weibull distribution method.
A suitable color space transformation and a way of extracting robust higher order features are
included in the method. Performance of the proposed scheme is compared against classical and
other vectorial approaches which have been proposed in the literature based on objective criteria.
Results showed that the proposed approach wins the other techniques available in the literature.
Application of the proposed method has been shown in edge detection applied on color images
taken from patients treated for diabetic retinopathy acquired from publicly available databases
and St. Paul’s Hospital Millennium Medical College. The algorithm performs well in detecting
exudates, hemorrhages, optical disc and blood vessels.
Description
Keywords
Color image analysis, Trinion, Quaternion, Opponent color space, Localized window, Central voxel, Diabetic Retinopathy, Hemorrhage, Exudates, Color gradient, Weibull distribution