i-manager's Journal on Image Processing (JIP)


Volume 1 Issue 3 July - September 2014

Article

A Review of Intensity and Model Based Segmentation Methods for MRI

R. Neela* , R. Kalaimagal**
* Research Scholar, Manonmaniam Sundaranar University, Tirunelveli, India.
** Assistant Professor, Department of Computer Science, Govt. Arts College for Men (Autonomous), Chennai, India.
Neela, R., and Kalaimagal, R. (2014). A Review of Intensity and Model Based Segmentation Methods for MRI. i-manager’s Journal on Image Processing, 1(3), 1-10. https://doi.org/10.26634/jip.1.3.2958

Abstract

Segmentation of various structures is a crucial step in the diagnosis and treatment of various diseases. Various imaging techniques such as X-ray, CT, (Computer Tomography), DTI (Diffusion Tensor Image), MRI (Magnetic Resonance Imaging), FMRI (Functional Magnetic Resource Imaging), PET (Positron Emission Tomography), SPECT (Single Photon Emission Computed Tomography), etc. are used in the treatment of diseases. Selection of the segmentation method depends on the modality used and the structures to be segmented. Accurate segmentation of various structures and computation of volume of tissues are required in the treatment of various diseases. In this paper, the authors present an overview of various segmentation techniques used in MRI analysis and their pros and cons. Also, the performance measures of some methods are evaluated.

Research Paper

Noise Minimization in Images using Dual-Tree Complex Wavelet Transform

M. Arunkumar* , D. Leela Rani**
* Student, Department of Electronics and Communication Engineering, Sree Vidyanikethan Engineering College, Tirupathi, A.P., India.
** Associate Professor, Department of Electronics and Communication Engineering, Sree Vidyanikethan Engineering College, Tirupathi, A.P., India.
Arunkumar, M., and Rani, D.L., (2014). Noise Minimization in Images using Dual-Tree Complex Wavelet Transform. i-manager’s Journal on Image Processing, 1(3), 11-17. https://doi.org/10.26634/jip.1.3.2959

Abstract

This paper presents a novel way to reduce noise introduced by different image enhancement techniques. As the human visual system is highly sensitive to change in brightness, the proposed method is applied to the luma channel of both the non-enhanced and enhanced image. The basic assumption is that the non-enhanced image is either free of noise or noise is present but not perceivable. In order to avoid inappropriate assumptions on the statistical characteristics of noise, a different one is proposed. Also, it gives the importance of directional content in human vision and the analysis is performed through the Dual-Tree Complex Wavelet Transform (DTCWT). Compared to discrete wavelet transform, the DTCWT provides distinction of data directionality in the transform space. The standard deviation for each level of the transform of an non-enhanced image coefficients is computed and normalized across the six orientations of the DTWCT. The normalized said map is then used to shrink the coefficients of the enhanced image. The shrunk coefficients of the enhanced image are mixed according to data directionality, with the coefficients of non-enhanced image. Finally, the inverse transform provides the noise-reduced version. The proposed one thoroughly reduces the noise introduced by the enhancement methods and produces better improvement in PSNR of the image. In order to confirm the validity of the proposed method, a through numerical analysis of the results has been done.

Research Paper

Comparison of PSNR of DCT, DWT and DTT using Telenuclear Medical Image

N. Harathi* , V. Meenakshi**, C.H. Suneetha***
*-** Assistant Professor, Department of EIE, Sree Vidyanikethan Engineering College, Tirupati.
*** Associate Professor, Department of ECE, Vignana Bharathi Institute of Technology, Aushapur.
Harathi, N., Meenakshi, V., and Suneetha, C.H. (2014). Comparison of PSNR of DCT, DWT and DTT using Telenuclear Medical Image. i-manager’s Journal on Image Processing, 1(3), 23-32. https://doi.org/10.26634/jip.1.3.2961

Abstract

The proliferation of digitized media due to the rapid growth of networked multimedia systems has created an urgent need for copyright enforcement technologies that can protect copyright. In this paper implementation of three different watermarking algorithms in the frequency domain is presented. The first algorithm is based on the Discrete Cosine Transform (DCT), the second one is based on the Discrete Wavelet Transform (DWT) and the third algorithm is based on the Discrete Tchebichef Transform (DTT).Embedding the watermark is done by modifying the coefficients of the middle frequency band so that the visibility of the image and diagnosis capability will not be affected. All schemes are tested using images and the simulation results are compared and the comparison shows the best scheme.

Research Paper

New Lifting Wavelets based Medical Image Compression with Entropy Coding

A. Hazarathaiah* , B. Prabhakara Rao**
* Head, Department of Electronics and Communications, S V College of Engineering.
** Rector, Jawarhalal Nehru technological University, Kakinada.
Hazarathaiah, A., and Rao, B.P. (2014). New Lifting Wavelets based Medical Image Compression with Entropy Coding. i-manager’s Journal on Image Processing, 1(3), 33-39. https://doi.org/10.26634/jip.1.3.2963

Abstract

The main limitations on any communication system are “channel bandwidth” and “noise”. This paper deals with the data rate which is related to channel bandwidth. The real time images from any source will occupy large amount of space on a storage device. Hence it consumes maximum bandwidth for transmitting it and there are so many methods to reduce the image size and hence the bandwidth of the signal. This paper shows wavelet based compression methods. Discrete Wavelet Transform is a powerful tool for analyzing the signals. With the help of a thresholding function, it will be more useful in compression, but this method has some disadvantages like selectivity and shift invariance. So a much better method is proposed. In the proposed method a completely new set of wavelets were designed with lifting filters. Arithmetic coding is combined with proposed algorithm for reducing the size of images with less mean square error (MSE) at high compression ratio (CR).