International Journal of Innovative Research and Development

P. S. Anupama , S. C. Prasanna Kumar , B. G. Sudharshan , N. Pradhan

Abstract

Magnetic Resonance Imaging (MRI) is a powerful diagnostic technique. However, the incorporated noise during image acquisition degrades the human interpretation, or computer-aided analysis of the images. Time averaging of image sequences aimed at improving the signal-to-noise ratio (SNR) would result in additional acquisition time and reduce the temporal resolution. Therefore, denoising should be performed to improve the image quality for more accurate diagnosis.This project implements different approaches of wavelet based image denoising methods. The wavelet transform is a simple and elegant tool that can be used for many digital signal processing applications. It overcomes some of the limitations of the Fourier transform with its ability to represent a function simultaneously in the frequency and time domains using a single prototype function (or wavelet) and its scales and shifts. In this project, some emerging wavelet domain Denoising methods such as soft and hard thresholding, bayeshrink, visushrink and SUREshrink are considered. The basic idea behind this thesis is the estimation of the uncorrupted image from the distorted or noisy image, and is referred to as image "denoising".

Keywords

Image Denoising, Soft and Hard, Thresholding, Bayeshrink, Visushrink, Sureshrink

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J. K. Priyanka , B. G. Sudarshan , S. C. Prasanna Kumar , N. Pradhan

Abstract

Retinex is a method used for image processing. Image processing has a great role in Medical science. Medical images such as MRI, CT, Ultrasound, X-Ray has to be processed for proper diagnosis. Retinex technique can be used for the processing of these images. By retinex processing it can provide better dynamic range compression, color consistency and lightness rendition. The different methods proposed by retinex algorithm includes Light Compensation Algorithm in Color Facial Image, Retinex for bridging the gap between color images and the human observation of scenes, Color Image Contrast Enhancement by Retinex, Color Image Enhancement with Adaptive Filter. In this paper we discuss about an algorithm for frequency domain based high resolution retinex for medical image processing. Initially we introduce Fast Fourier Transform to the image. Then Gaussian filtering is done and the inverse fourier transform is taken. Next step is to apply logarithmic function. Finally gain/offset is applied to obtain the enhanced output image. The method can produce good contrast enhancement. It can be used for both color image and gray image. Since it can process gray images the medical images can be processed successfully. The output for Single Scale Retinex, Multi Scale Retinex and Multi Scale Retinex with Color Restoration are obtained.

Keywords

Retinex, Dynamic Range Compression, Colorconsistency, Gaussian Filtering, Multi-scale Retinex, Multi Scale Retinex with Color Restoration, Single-scale Retinex

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J. K. Priyanka , B. G. Sudarshan , S. C. Prasanna Kumar

Abstract

Retinex is a method used for image processing. A computation for color images that approaches to scene observation must combine dynamic range compression, color consistency and color and lightness tonal rendition. A previously designed Single-Scale Retinex (SSR) to a Multi-Scale Retinex (MSR) version that achieves simultaneous dynamic range compression, color consistency, lightness rendition. But this fails to produce good color rendition. To address this problem, the Multi Scale Retinex with Color Restoration (MSRCR) was proposed. The different methods proposed by retinex algorithm includes the multiscale retinex with color restoration, Light Compensation Algorithm in Color Facial Image, Laminance Based MSR algorithm, Adaptive Color Restoration and Luminance MSR, MSR modification to preserve color fidelity while enhancing contrast, Algorithm for MSR method based on modified color restoration, Color Image enhancement algorithm based on human visual system based on adaptive filter, Fusion based approach on MSRCR, Color Image contrast enhancement algorithm by retinex model, Automated multi scale retinex with color restoration, Enhancement of mammographic feature by multiscale analysis, Nonlinear method to enhance images using improved SSR algorithm, Multi-dimensional multi-scale imageprocessing algorithm, nonlinear multi-scale enhancement algorithm for chest radiography, Ultrasound Liver Image Enhancement Algorithm Based on MSR, Algorithm based on the SSR to enhance the tiny anatomical structures and other regions of interest on the Low-dose CT images. On comparison of original image, SSR image, MSR image, MSRCR image and other image enhancement methods. Finally it is concluded that output of MSRCR is better than other techniques.

Keywords

Retinex, Dynamic Range Compression, Color Restoration, Multi-scale Retinex, Multi Scale, Retinex with Color Restoration, Single-scale Retinex

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P. S. Anupama , S. C. Prasanna Kumar , B. G. Sudharshan , N. Pradhan

Abstract

Removing noise from the original signal is still a challenging problem for researchers. In medical image processing, image denoising has become a very essential exercise all through the diagnose. Arbitration between the perpetuation of useful diagnostic information and noise suppression must be treasured in medical images. In general we rely on the intervention of a proficient to control the quality of processed images. In certain cases, for instance in Ultrasound images, the noise can restrain information which is valuable for the general practitioner, Consequently medical images are very inconsistent, and it is crucial to operate case to case, The wavelet transform is a simple and elegant tool that can be used for many digital image processing applications. It overcomes some of the limitations of the fourier transform with its ability to represent a function simultaneously in the frequency and time domains using a single prototype function (or wavelet) and its scales and shifts. There have been several published algorithms and each approach has its assumptions, advantages, and limitations. This paper presents a review of some significant work in the area of image denoising.

Keywords

Image Denoising, Digital Linage Processing, Ultrasound Imaging, Wavelet
Transform, Fourier Transform

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