P. Rajesh Kumar

Work place: Dept. of Electronics and Communication Engineering, Andhra University, Visakhapatnam, India

E-mail: rajeshauce@gmail.com


Research Interests: Image Compression, Image Manipulation, Image Processing


Dr. P. Rajesh Kumar is a Professor in Electronics and Communication Engineering department, College of Engineering, Andhra University, Visakhapatnam, India. He received his M.E. and Ph.D. from Andhra University. He has twenty two years experience of teaching undergraduate, postgraduate and guided more than hundred postgraduate theses. He has published more than hundred research papers in National and International Journals and fifteen research scholars received PhD under his guidance. Presently he is guiding ten PhD students and his research interests are in the area of Digital image processing, Digital signal processing, Radar signal processing and Biomedical signal processing.

Author Articles
A New Robust and Imperceptible Image Watermarking Scheme Based on Hybrid Transform and PSO

By Tamirat Tagesse Takore P. Rajesh Kumar G. Lavanya Devi

DOI: https://doi.org/10.5815/ijisa.2018.11.06, Pub. Date: 8 Nov. 2018

In this paper, a new robust and imperceptible digital image watermarking scheme that can overcome the limitation of traditional wavelet-based image watermarking schemes is proposed using hybrid transforms viz. Lifting wavelet transform (LWT), discrete cosine transform (DCT) and singular value decomposition (SVD). The scheme uses canny edge detector to select blocks with higher edge pixels. Two reference sub-images, which are used as the point of reference for watermark embedding and extraction, have been formed from selected blocks based on the number of edges. To achieve a better trade-off between imperceptibility and robustness, multiple scaling factors (MSF) have been employed to modulate different ranges of singular value coefficients during watermark embedding process. Particle swarm optimization (PSO) algorithm has been adopted to obtain optimized MSF. The performance of the proposed scheme has been assessed under different conditions and the experimental results, which are obtained from computer simulation, verifies that the proposed scheme achieves enhanced robustness against various attacks performed. Moreover, the performance of the proposed scheme is compared with the other existing schemes and the results of comparison confirm that our proposed scheme outperforms previous existing schemes in terms of robustness and imperceptibility.

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Robust Image Watermarking Scheme Using Population-Based Stochastic Optimization Technique

By Tamirat Tagesse Takore P. Rajesh Kumar G. Lavanya Devi

DOI: https://doi.org/10.5815/ijigsp.2017.07.06, Pub. Date: 8 Jul. 2017

Designing an efficient watermarking scheme that can achieve better robustness with limited visual quality distortion is the most challenging problem. In this paper, robust digital image watermarking scheme based on edge detection and singular value decomposition (SVD) is proposed. Two sub-images, which are used as a point of reference for both watermark embedding and extracting, are formed from blocks that are selected based on the number of edges they have. Block based SVD is performed on sub-images to embed a binary watermark by modifying the singular value (S). A population-based stochastic optimization technique is employed to achieve enhanced performance by searching embedding parameters which can maintain a better trade-off between robustness and imperceptibility. The experimental results show that the proposed method achieves improved robustness against different image processing and geometric attacks for selected quality threshold. The performance of the proposed scheme is compared with the existing schemes and significant improvement is observed.

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Color Histogram and DBC Co-Occurrence Matrix for Content Based Image Retrieval

By K. Prasanthi Jasmine P. Rajesh Kumar

DOI: https://doi.org/10.5815/ijieeb.2014.06.06, Pub. Date: 8 Dec. 2014

This paper presents the integration of color histogram and DBC co-occurrence matrix for content based image retrieval. The exit DBC collect the directional edges which are calculated by applying the first-order derivatives in 0º, 45º, 90º and 135º directions. The feature vector length of DBC for a particular direction is 512 which are more for image retrieval. To avoid this problem, we collect the directional edges by excluding the center pixel and further applied the rotation invariant property. Further, we calculated the co-occurrence matrix to form the feature vector. Finally, the HSV color histogram and the DBC co-occurrence matrix are integrated to form the feature database. The retrieval results of the proposed method have been tested by conducting three experiments on Brodatz, MIT VisTex texture databases and Corel-1000 natural database. The results after being investigated show a significant improvement in terms of their evaluation measures as compared to LBP, DBC and other transform domain features.

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Color and Local Maximum Edge Patterns Histogram for Content Based Image Retrieval

By K. Prasanthi Jasmine P. Rajesh Kumar

DOI: https://doi.org/10.5815/ijisa.2014.11.09, Pub. Date: 8 Oct. 2014

In this paper, HSV color local maximum edge binary patterns (LMEBP) histogram and LMEBP joint histogram are integrated for content based image retrieval (CBIR). The local HSV region of image is represented by LMEBP, which are evaluated by taking into consideration the magnitude of local difference between the center pixel and its neighbors. This LMEBP differs from the existing LBP in a manner that it extracts the information based on distribution of edges in an image. Further the joint histogram is constructed between uniform two rotational invariant first three LMEBP patterns. The color feature is extracted by calculating the histogram on Hue (H), Saturation (S) and LMEBP histogram on Value (V) spaces. The feature vector of the system is constructed by integrating HSV LMEBP histograms and LMEBP joint histograms. The experimentation has been carried out for proving the worth of our algorithm. It is further mentioned that the databases considered for experiment are Corel-1K and Corel-5K. The results after being investigated show a significant improvement in terms of their evaluation measures as compared to previously available spatial and transform domain methods on their respective databases.

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Color and Rotated M-Band Dual Tree Complex Wavelet Transform Features for Image Retrieval

By K. Prasanthi Jasmine P. Rajesh Kumar

DOI: https://doi.org/10.5815/ijigsp.2014.09.01, Pub. Date: 8 Aug. 2014

In this paper, a novel algorithm which integrates the RGB color histogram and texture features for content based image retrieval. A new set of two-dimensional (2-D) M-band dual tree complex wavelet transform (M_band_DT_CWT) and rotated M_band_DT_CWT are designed to improve the texture retrieval performance. Unlike the standard dual tree complex wavelet transform (DT_CWT), which gives a logarithmic frequency resolution, the M-band decomposition gives a mixture of a logarithmic and linear frequency resolution. Most texture image retrieval systems are still incapable of providing retrieval result with high retrieval accuracy and less computational complexity. To address this problem, we propose a novel approach for image retrieval using M_band_DT_CWT and rotated M_band_DT_CWT (M_band_DT_RCWT) by computing the energy, standard deviation and their combination on each subband of the decomposed image. To check the retrieval performance, two texture databases are used. Further, it is mentioned that the databases used are Brodatz gray scale database and MIT VisTex Color database. The retrieval efficiency and accuracy using proposed features is found to be superior to other existing methods.

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Wavelet Transform Techniques for Image Compression – An Evaluation

By S. Sridhar P. Rajesh Kumar K.V.Ramanaiah

DOI: https://doi.org/10.5815/ijigsp.2014.02.07, Pub. Date: 8 Jan. 2014

A vital problem in evaluating the picture quality of an image compression system is the difficulty in describing the amount of degradation in reconstructed image, Wavelet transforms are set of mathematical functions that have established their viability in image compression applications owing to the computational simplicity that comes in the form of filter bank implementation. The choice of wavelet family depends on the application and the content of image. Proposed work is carried out by the application of different hand designed wavelet families like Haar, Daubechies, Biorthogonal, Coiflets and Symlets etc on a variety of bench mark images. Selected benchmark images of choice are decomposed twice using appropriate family of wavelets to produce the approximation and detail coefficients. The highly accurate approximation coefficients so produced are further quantized and later Huffman encoded to eliminate the psychovisual and coding redundancies. However the less accurate detailed coefficients are neglected. In this paper the relative merits of different Wavelet transform techniques are evaluated using objective fidelity measures- PSNR and MSE, results obtained provide a basis for application developers to choose the right family of wavelet for image compression matching their application.

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