796 research outputs found
A Novel Approach for Quaternion Algebra Based JSEG Color Texture Segmentation
In this work, a novel colour quantization approach has been applied to the JSEG colour texture segmentation using quaternion algebra. As a rule, the fundamental vectors of the colour space are derived by inverting the three RGB colour directions in the complex hyperplanes. In the proposed system, colour is represented as a quaternion because quaternion algebra provides a very intuitive means of working with homogeneous coordinates. This representation views a colour pixel as a point in the three-dimensional space. A novel quantization approach that makes use of projective geometry and level set methods has been produced as a consequence of the suggested model. The JSEG colour texture segmentation will use this technique. The new colour quantization approach utilises the binary quaternion moment preserving thresholding methodology, and is therefore a splintering clustering method. This method is used to segment the colour clusters found inside the RGB cube and the colour consistency throughout the spectrum and in the space are both considered. The results of the segmentation are compared with JSEG as well as with the most recent standard segmentation techniques. These comparisons show that the suggested quantization technique makes JSEG segmentation more robust
Two-sided Clifford Fourier transform with two square roots of -1 in Cl(p,q)
We generalize quaternion and Clifford Fourier transforms to general two-sided
Clifford Fourier transforms (CFT), and study their properties (from linearity
to convolution). Two general \textit{multivector square roots} \in \cl{p,q}
\textit{of} -1 are used to split multivector signals, and to construct the left
and right CFT kernel factors.
Keywords: Clifford Fourier transform, Clifford algebra, signal processing,
square roots of -1 .Comment: 19 pages, 1 figur
The development of the quaternion wavelet transform
The purpose of this article is to review what has been written on what other authors have called quaternion wavelet transforms (QWTs): there is no consensus about what these should look like and what their properties should be. We briefly explain what real continuous and discrete wavelet transforms and multiresolution analysis are and why complex wavelet transforms were introduced; we then go on to detail published approaches to QWTs and to analyse them. We conclude with our own analysis of what it is that should define a QWT as being truly quaternionic and why all but a few of the “QWTs” we have described do not fit our definition
A Method of Segmentation for Hyper spectral & Medical Images Based on Color Image Segmentation
The paper propose an original and simple segmentation strategy based on the EM approach for hyper spectral images . In a first step, to simplify the input color textured image into a color image without texture. The final segmentation is simply achieved by a spatially color segmentation using feature vector with the set of color values contained around the pixel to be classified. The spatial constraint allows taking into account the inherent spatial relationships of any image and its colours. This approach provides effective PSNR for the segmented image. These results omit the better performance athe segmented images are compared with Watershed & Region Growing Algorithm. This approach provides the effective segmentation for the Spectral Images & Medical Images. With proposed approach it can be fascinated that the data obtained from the segmentation can provide accurate information from the huge image
Automatic age and gender classification using supervised appearance model
YesAge and gender classification are two important problems that recently gained popularity in the
research community, due to their wide range of applications. Research has shown that both age and gender
information are encoded in the face shape and texture, hence the active appearance model (AAM), a statistical
model that captures shape and texture variations, has been one of the most widely used feature extraction
techniques for the aforementioned problems. However, AAM suffers from some drawbacks, especially when
used for classification. This is primarily because principal component analysis (PCA), which is at the core of
the model, works in an unsupervised manner, i.e., PCA dimensionality reduction does not take into account
how the predictor variables relate to the response (class labels). Rather, it explores only the underlying structure
of the predictor variables, thus, it is no surprise if PCA discards valuable parts of the data that represent discriminatory
features. Toward this end, we propose a supervised appearance model (sAM) that improves on AAM
by replacing PCA with partial least-squares regression. This feature extraction technique is then used for the
problems of age and gender classification. Our experiments show that sAM has better predictive power than the
conventional AAM
Multi-directional colour edge detector using linear quaternion system convolution
A new linear colour image filter based on linear quaternion systems (LQSs) is introduced. It detects horizontal, vertical, left- and right-diagonal edges with a single LQS convolution mask. The proposed filter is a canonic minimal filter of four LQS filters, each with different angles of rotation combined parallel wise. Different angles of rotation are a key features of the new filter such that horizontal, vertical, left, and right-diagonal LQS filter masks rotate pixels through angles π/2, 5π/2, 3π/2, and 7π/2, respectively. Although, the four LQS masks are combined parallel to make a single LQS mask but derived using four quaternion convolutions, one for each direction of edges, the LQS filter produces a result without the combination of results from four separate edge detectors. This methodology could be generalised to design more elaborate LQS filters to perform other geometric operations on colour image pixels. The proposed filter translates smoothly changing colours to different shades of grey and produces coloured edges in multiple directions, where there is a sudden change of colour in the original image. Another key idea of the proposed filter is that it is linear because it operates in homogeneous coordinates
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