International Journal of Engineering Trends and Technology (IJETT) – Volume 24 Number 2- June 2015 Comparative Analysis of Image De-noising with Different Filters in Wavelet Domain Mr.Ashutosh Dwivedi1, Mr.Pratik Soni2, Mr.Virendra k Verma3 Department of Electronics and Communication Engineering, SIMS Indore MP Abstract- Graphical images are very fundamental type of data for transmission. Due to the different components and high speed transmission, image is corrupted by the noises. Image detection is required during data receiving end for the faithful communication. There are various methods for picture denoising in spatial and transform domain. The present trends of the picture detection research are the evolution of mixed domain methods. In this comparison paper, a comparative analysis of picture denoising using different filters with mixed domain image denoising method is proposed, which is based on the wavelet transform, median filter and nonlinear diffusion based methods. The wavelet transform is used in this paper to convert the spatial domain image to wavelet domain coefficients. WT produces approximation, horizontal detail, vertical detail and diagonal detail coefficient which represent the various spatial frequency bands. The detail component are removed due to the most of the image part is in approximation part. Median and wiener filter are used to apply the filtering on probabilistic way. The trapezoidal membership function are used for the filtering .The peak signal to noise ratio (PSNR) and mean square error (MSE) are used as the performance parameter. The Haar wavelet is used with various filters to optimize the performance of denoising. Keywords: MSE, PSNR, Wavelet Transform. 1. 2. DENOISING METHODS 2.1. Wavelet Transform The wavelet expansion set is not unique. A wavelet system is a set of building blocks to construct or represent a signal or function. While concerning 2D image wavelet decomposition the transform can be carried out with a vertical operation to obtain finally four sub image representation [5]. As shown in figure1 two sub images are generate after 2D image decomposition original image into two parts one high frequency coefficient and low frequency. The image HL is the vertical direction high frequency component, LH the horizontal direction high frequency component and LL sub image is the horizontal and vertical direction low frequency component and the HH sub image is the diagonal direction high frequency component. [6]. 2.2. Wiener Filter INTRODUCTION Denoising picture is a method to make an image comprehensible to the human visual system. Digital image are often effect by noise or blurred. Every digital camera imperfection called noise that is nothing but noise which affects the image such as in visual quality and others. Noise may be classified as substitutive noise (impulsive noise: e.g., salt and pepper noise, random valued impulse noise, etc.)[1], additive noise (e.g., additive white Gaussian noise) and multiplicative noise (e.g. speckle noise). Types of image denoising are spatial domain methods and wavelet domain methods [2]. The special filtering is one of the classical linear filtering in spatial domain while the wavelet domain is a new signal estimation method [3]. Wiener Filter for image restoration of blurred image, Wiener Filter shows noise as random process and find estimate of the uncorrupted image such as mean square error between them in minimized e.g. wiener filter can be regarded as a linear estimating method[4]. when we apply Wavelet transform on 2D image and work with their detail and approximate coefficient in wavelet domain ,the wavelet domain is used for ISSN: 2231-5381 disintegration of image, but still there is some draw backs for those we will use Fuzzy logic in future which will be based on triangular member function (e.g. ATMAV, ATMED FILTERS[10]) and performance evaluated on MATLAB. The most important technique for removal of blur in images due to linear motion or unfocussed optics is the Wiener Filter. From a signal processing standpoint, blurring due to linear motion in a photograph is the result of poor sampling. Each pixel in a digital representation of the photograph should represent the intensity of a single stationary point in front of the camera. Unfortunately, if the shutter speed is too slow and the camera is in motion, a given pixel will be an amalgam of intensities from points along the line of the camera's motion [7]. The process of extracting the information carrying signal X(n) from the observed signal Y(n). Y(n) = X(n) + N(n) Where: N (n) = noise process X(n) X Y(n) H(n) Y(n) N(n) http://www.ijettjournal.org Page 77 International Journal of Engineering Trends and Technology (IJETT) – Volume 24 Number 2- June 2015 2.3. Median Filter The Median Filter in the Fourier domain is given by the expression [8] median filter is presented to provide optimum detail preservation along with very high density noise removal. The quantitative measures in terms of MSE and PSNR and as well as visual comparisons, it is evident that for high-density noise levels Mr. Madeena sultana proposed algorithm confirms it effectiveness in removing high-density impulse noises as well as preserving fine details. Where: H (u,v) is the degraded function H* (u; v) is the complex conjugate of H (u,v) jH(u; v)j2 = H*(u; v)H(u; v) S´(u; v) = jN(u; v)j2 is the power spectrum of the noise Sf (u; v) = jF (u; v)j2 is the power spectral density (PSD) of the undergirded image The above expression is based on the following assumptions: Figure 2. Comparison of PSNRs for the restored “mandrill” image obtained after applying different filters at different noise densities. [12] 1. The noise and the image are uncorrelated 2. The noise or the image has zero mean 3. The gray levels in the estimate are a linear function of the levels in the degraded image. The Median Filter handles the situation in which the degradation function is zero, unless both the degradation function as well as the noise power spectrum is zero. 3. LITERATURE REVIEW One of the fundamental challenges is to estimate the original image by suppressing noise from a noise-contaminated version of the image. Image noise may be caused by different intrinsic (i.e., sensor) and extrinsic (i.e., environment) conditions which are often not possible to avoid in practical situations. Now here there are some problems which are investigated during the study of papers on previous years work done 3.1 High Density impulse denoising by A novel Adaptive Fuzzy Filter by Mr. Madeena Sultana [12] Traditional median filters perform well in restoring the images corrupted by low density impulse noise, but fail to restore highly corrupted images. Conversely, the advanced adaptive median filters are capable of denoising high density impulse noise but the image details are compromised significantly. In this paper, a new adaptive fuzzy ISSN: 2231-5381 The problem in the above methodology is that it does not minimize the quantization Error as well as peak signal to noise ratio has not sufficient values as compare to original value. 3.2 High Performance Filter Based on Statistic methods for image processing by Pao-ta yu [11] Experimental results demonstrate that the HPFSM system achieves high performance for image processing and outperforms the existing wellknown methods, even if there are many blocks of noisy pixels at the high noise rate of images Figure. 3 Comparison of various filters in terms of PSNR for corrupted “Lena” image. [11] Simulation results show that the HPFSM system definitely serves as a perfect image processor and outperforms the existing well-known filters, even in many blocks of noisy pixels at the high noise rate of images. http://www.ijettjournal.org Page 78 International Journal of Engineering Trends and Technology (IJETT) – Volume 24 Number 2- June 2015 This paper has proposed an image processing technology, called the HPFSM system, which integrates with Chebyshev’s theorem and a fuzzy mean process to estimate the Dependable Interval for impulse noise detection. And a novel method by the scope of mean-closure function with a Growing Window is proposed to use for restoring corrupted pixels. Now the problem in this research work is still not improve the peak signal to noise ratio apart from minimizing the root mean square error. 3.3 Performance Evaluation and comparison of modified Denoising method and the local adaptive wavelet image denoising method by Ms. Jignasa M. permar [10] The denoising of image is initial step in image processing. The quality of the denoise image depends on the two major parts: wavelet transform for decomposition of image and adaptive wiener filtering in wavelet domain and spatial domain. The performance of the local adaptive wavelet image denoising method is good compared to modified denoising method in terms of PSNR between denoise image and original image. Table: 1 Comparison of both method with PSNR between original and denoise image at different noise variance level. [10] Noise Variance 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 Noise image PSNR in db Modified denoising methods 13.8489 11.5180 10.3545 9.6045 9.1220 8.7022 8.3902 8.1842 22.4287 20.7711 19.6614 18.8588 18.2660 17.7009 17.2069 16.9228 The local adaptive wavelet image denoising methods 23.4628 21.2357 19.8178 18.9278 18.3018 17.7499 17.2419 17.0181 Hence, from these results it can be concluded that the local adaptive wavelet image denoising method is more effective for suppression of noisy image with AWGN than others. Thus the image after denoising have a better visual effect and preserve the detail edges of image. In the above research work they have made the filtering with the combination of weiner filter and wavelet transform, results with this are quite better as compare to previous research but still we have to improve the both parameters 4. PROPOSED WORK ISSN: 2231-5381 In the standard moving average filter the value at the central pixel of the window is replaced by the mean value of the corresponding input neighborhood. 4.1. ATMED Asymmetrical Triangular Median Filter (ATMED) is a given neighborhood the filter takes into account the deviation of the pixel value with the median value and replaces the noisy pixel with a fitting output based on fuzzy triangular membership functions [9].The fuzzy filter with triangular function and median value within a window as the center value is given as, O(x,y) Where: Imax(x, y), Imin (x,y), and Imed (x,y) are the maximum value, the minimum value and the median value in the neighborhood [9]. 4.2. ATMAV Asymmetrical Triangular Moving Average Filter (ATMAV) is a given neighborhood the filter takes into account the deviation of the pixel value with the mean value and replaces the noisy pixel with a fitting output based on fuzzy triangular membership functions [9]. O(x,y) Where: IMAX(x, y), Imin (x, y), and Imed (x, y) are the maximum value, the minimum value and the median value in the neighborhood. 4.3. METHODOLOGY First select an image, check, is it gray image or color image? If color image then firstly convert this image into gray image. Then use it as input image. The next step will be to apply wavelet transform (DWT) to decompose the noisy http://www.ijettjournal.org Page 79 International Journal of Engineering Trends and Technology (IJETT) – Volume 24 Number 2- June 2015 image into four sub images: LL, HL, LH, and HH. After this adopt wiener filter for LL sub image and apply thresholding to remaining sub images. After this step we apply median filter and wiener filter with haar wavelet one by one. Then reconstructs image by wavelet inverse transform, and gets the denoise image. Fig 4: (a) Fig 4: (b) Finally, calculate PSNR between original image and noisy image and RMSE between the denoise image and original image.[10] 5. COMPARATIVES RESULTS The performance for denoising of image were tested on set of grayscale images such as Lena image, (512 512). Add the noise to the image based on different values of variance. Perform image denoising via wavelet [8] and wiener filter and median filter with haar wavelet [9]. Table shows the combination different methods (PSNR, RMSE) at different noise level. The Wiener with haar wavelet are giving the best denoising result. Apart from this the comparison has been done including Median filter and high performance filter based on statistic methods for image processing. Robustness and detail preservation are the two most important aspects of modern image enhancement filters. In this paper, we proposed a new fuzzy-based adaptive algorithm that provides robustness across a wide variation of high impulse noise, without significant deterioration of fine details of the original image. Table2: Comparison of various Filters in terms of PSNR values for corrupted “Lena” image [11] Noise variance Median Filters HPFSM 0.01 34.44 42.82 119.42 120.50 0.02 34.14 40.21 76.89 80.60 0.03 33.78 38.18 50.129 60.50 0.04 33.21 36.78 49.235 50.40 ISSN: 2231-5381 Wiener Proposed Fig 4: (c) Fig 4: (d) Figure 4: Resulting images from different noise (a) Original image (b) median filter (c) HPFSM (d) Wiener 6. CONCLUSION Based on the comparative result, we conclude that The median filter with haar gives worst result for image denoising. HPFSM gives better results compare to median filter. The wiener filter with haar wavelet gives good result as compared to median filter. Thus we conclude that with haar wavelet is better technique for image denoising. 7. REFERENCES [1] R C Gonzalez and R .E.Wood Digital image processing Prentice hall, upper saddle river, N .J.,2nd edition, 2002. [2] Huipin Zhang,Aria Nosratinia and R. 0.Wells, “Image Denoising Via Wavelet-Domain Spatially Adaptive FIR Wiener Filtering”, IEEE Trans., pp.2179-2182, 2000. [3] Xiwen Qin , Yang Yue, Xiaogang Dong and Xinmin Wang , ZhanSheng Tao “An Improved Method of Image Denoising Based on Wavelet Transform” International Conference on Computer, Mechatronics, Control and Electronic Engineering (CMCE) 2010. [4] Li Ke, Weiqi Yuan and Yang Xiao, “An Improved Wiener Filtering Method in Wavelet Domain”, IEEE Trans., ICALIP, pp.1527-1531, August 2008. [5] Sachin D Ruikar and Dharmpal D Doye “Wavelet Based Image Denoising Technique” (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 2, No.3, March 2011. [6] Li Shixin, Zhang Xinghui and Wang Jianming “A new Local Adaptive Wavelet Image De-noising Method”, IEEE Computer Society, ISCCS, pp.154-156, 2011. [7]https://www.clear.rice.edu/elec431/projects95/lords/wiener.ht ml [8] Nevine Jacob and Aline Martin “Image Denoising In the Wavelet Domain Using Wiener Filtering” December 17, 2004. http://www.ijettjournal.org Page 80 International Journal of Engineering Trends and Technology (IJETT) – Volume 24 Number 2- June 2015 [9] Stefan Schulte, Valerie De Witte and Etienne E.Kerre, “ A Fuzzy Noise Reduction Method For Color Images” IEEE Transactions on image Processing, Vol 16, No.5, May 2007. [10] Jin F,Fiegush, P,Winger L et al., “Adaptive Wiener filtering of noisy images and image sequences”, Proceedings of the IEEE International Conference on Image Processing, ICIP,Vol.3, pp.349-352, 2003. [11] Pao-Ta Yu*,1, Yui-Lang Chen1 “A High Performance Filter Based on Statistic Methods for image processing “978-0-76953382-7/08 $25.00 © 2008 IEEE DOI 10.1109/ISDA.2008.34 [12] Madeena Sultana” High Density Impulse Denoising by A Novel adaptive fuzzy filter 978-1-4799-0400-6/13/$31.00 ©2013 IEEE ISSN: 2231-5381 http://www.ijettjournal.org Page 81