International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) Analysis of Orthogonal and Biorthogonal Mother Wavelet Using Gaussian noise for Image Denoising Reena Thakur1 Guru Nanak Institute Of Engineering and Technology, Nagpur University, Maharashtra, India Abstract This paper analyzes the performance of orthogonal and Biorthogonal mother wavelets for image denoising using Gaussian noise on various images. These images to be tested are of different size and resolution. The performance of denoised image is measured, subjectively visual quality of image and objectively peak signal to noise ratio and it is found that Biorthogonal wavelets outperform the orthogonal ones in both the criteria. Keywords- Denoising , Wavelets, Peak Signal to noise ratio, Orthogonal, Biorthogonal, Mean Squarred error, Mother Wavelets. 1. INTRODUCTION Computer becoming more powerful day by day. Image denoising is still a challenging problem for researchers as image denoising causes blurring and introduces artifacts .It has become a very critical exercise of inverse problems in image processing. Wavelet denoising using its families is a more successful kind of application of wavelet transforming. The blemish of signal acquisition devices is added with noises which can be reduced by estimator using prior information on signal properties. Noise is unwanted signal that hinders with the original signal and disgraces the visual quality of original image. The key sources of noise in images are imperfect instruments, problem with data gaining process, intrusion natural phenomena, compression and transmission [1]. Image denoising forms the preprocessing step in the field of image processing, medical fields, research, and technology, where somehow image has been degraded and needs to be restored before further processing. Different types of images inherit different types of noise and different noise models are used to present different noise types. Denoising is a way to get rid of the effect of noise and to improve the signal-noise ratio and we have used Gaussian noise. In [1] the author uses wavelet transform in connection with threshold functions for removing noise and also Universal, Visu Shrink, Sure Shrink and Bayes Shrink, normal shrink are compared with their threshold function, which improves the SNR efficiently but depends on the nature of image. In [2] the author proposed a method to remove the noise of QuickBird images based on the wavelet packet transform after analyzing the characteristics of wavelet packet transform. The analytical results show that wavelet packet transform performs effectively in removing the noise of QuickBird images compared with other methods. Wavelet transform is one of the promising methods of image denoising. The basic measure of the performance of a denoising algorithm is the quality of image and peak signal to noise ratio, which is defined by the ratio between original image and denoised image. In the present work, we analyze various wavelet families for image denoising on variety of test images and then compare the performance of wavelets. According to this analysis, we show the selection of the optimal wavelet for image denoising taking into account Peak Signal to Noise Ratio (PSNR) as objective and visual quality of image as subjective quality measure. As we go down, section II describes the methodology used that is Wavelet Families for denoising , section III and IV describes quality measures including type of noise used, section V describes experimental work result and discussion of results and finaly section VI describes conclusion and references. Organized By: GNI Nagpur, India International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) 2. MOTHER WAVELETS Wavelet families can be divided into two main categories, orthogonal and Biorthogonal wavelets, which have different properties of basis functions. Orthogonality decorrelates the transform coefficients there by minimizing redundancy. Symmetry provides linear phase and minimize border arti-facts Other Important properties of wavelet functions in image denoising applications are compact support, symmetry, regularity and degree of smoothness [3] [4]. Figure 1 illustrates some of the commonly used wavelet functions in our experiments. Fig. 1 Some of the wavelet mothers used in our experiments 3. QUALITY MEASURES The performances of image denoising techniques are mainly analyzed on the basis of : Noise varience and Peak Signal to noise ratio (PSNR) which is the ratio between noisy image and denoised image. PSNR provides a measurement of the amount of distortion in a signal [5], with a higher value indicating less distortion. For nbits per pixel image, PSNR is defined as: PSNR 2n 1 20log10 RMSE Where, RMSE is the root mean square difference between two images. The Mean Square Error (MSE) is defined as follows [6]: MSE 1 MN M 1N 1 y (m, n) x(m, n) 2 m 0n 0 where x(m,n),y(m,n) are respectively the original and recovered pixel values at the mth row and nth column for MxN size image. PSNR is normally quoted in decibels (dB), which measure the ratio of the peak signal and the difference between two images (error image). Logically, a higher value of PSNR is good because it means that the ratio of Signal to Noise is higher. So, if we find a denoised scheme having a high PSNR, we can recognize that it is a better one. 4. GAUSSIAN NOISE Gaussian noise is evenly distributed over the signal [7]. This means that each pixel in the noisy image is the sum of the true pixel value and a random Gaussian distributed noise value. This noise has a Gaussian distribution as the name indicates, which has a bell shaped probability distribution function given by, Organized By: GNI Nagpur, India International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) 1 2 F (g) e g m /2 2 2 2 where g represents the gray level, m is the mean or average of the function, and σ is the standard deviation of the noise. 5. EXPERIMENTAL RESULTS , ANALYSIS AND COMPARISON We analyze orthogonal and Biorthogonal wavelet families for image denoising and compare their results. We used four types of test images with different frequency content, different resolution and different size: Rose(128X85),Globe(260X173),Car(259X194),Horse(225X226). TABLE 1 Wavelet family daubachies PSNR (in DB) Horse db6 db10 db20 0.01 28.68 28.81 28.81 28.77 28.75 0.02 28.36 28.47 28.44 28.46 28.41 0.03 28.26 28.31 28.30 28.30 28.23 0.04 28.21 28.25 28.15 28.21 28.23 28.5 0.05 28.12 28.15 28.15 28.16 28.18 28 0.01 29.15 29.16 29.21 29.16 29.13 0.02 27.64 27.63 27.70 27.64 27.65 27.5 db4 0.03 27.06 27.06 27.05 27.08 27.07 27 0.04 26.85 26.85 26.84 26.84 26.87 db6 0.05 26.73 26.71 26.72 26.72 26.73 0.01 28.58 28.57 28.59 28.58 0.02 28.27 28.30 28.26 28.29 0.03 28.13 28.16 28.16 28.13 28.16 0.04 28.08 28.08 28.10 28.08 28.05 0.05 28.02 28.02 28.04 28.01 28.01 0.01 28.52 28.49 28.56 28.53 28.48 0.02 28.15 28.12 28.18 28.15 28.13 0.03 28.01 28.00 28.02 28.01 27.98 0.04 27.96 27.93 27.93 27.92 27.89 0.05 27.90 27.88 27.91 27.89 27.85 29.5 29 db2 26.5 db10 28.58 26 db20 28.27 25.5 Wavelet family biorthogonal PSNR (in DB) Rose Var 0.01 bior 1.3 28.71 bior 1.5 28.73 bior 2.2 28.76 bior 2.4 28.75 bior 2.6 28.83 0.02 28.32 28.37 28.36 28.45 28.48 0.03 28.28 28.22 28.29 28.30 28.29 0.04 28.21 28.17 28.22 28.20 28.23 0.05 28.13 28.11 28.11 28.14 28.20 0.04 Fig. 2 Graphical Performance of Daubachies family TABLE 2 Image 0.01 0.03 25 0.05 Car db4 0.02 Globe db2 0.04 Rose Var 0.01 Image Organized By: GNI Nagpur, India International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) Globe Car Horse 0.01 29.18 29.21 29.27 29.25 29.24 0.02 27.69 27.67 27.66 27.64 27.69 0.03 27.07 27.11 27.09 27.06 27.01 0.04 26.85 26.87 26.82 26.84 26.85 0.05 26.72 26.74 26.74 26.72 26.72 0.01 28.54 28.57 28.60 28.58 28.62 0.02 28.25 28.27 28.27 28.26 28.28 0.03 28.10 28.15 28.14 28.12 28.15 0.04 28.07 28.06 28.07 28.08 28.08 0.05 28.02 28.01 28.02 28.03 28.04 0.01 28.56 28.50 28.52 28.59 28.55 27 bior2.2 0.02 28.14 28.14 28.12 28.18 28.18 26.5 bior2.4 0.03 28.00 27.99 27.97 28.00 28.01 0.04 27.93 27.91 27.92 27.92 27.92 26 bior2.6 0.05 27.85 27.85 27.86 27.88 27.88 29.5 29 28.5 28 bior1.3 27.5 bior1.5 25.5 0.02 0.03 0.04 0.05 0.01 25 Fig 3. Graphical performance of Symlet family TABLE 3 Wavelet family Symlet PSNR (in DB) Image Rose Variance Sym2 Sym3 Sym5 Sym10 Sym12 0.01 28.73 28.73 28.79 28.70 28.72 0.02 28.36 28.37 28.44 28.41 28.42 0.03 28.22 28.27 28.28 28.26 28.24 0.04 28.23 28.19 28.23 28.18 28.13 0.05 28.12 28.16 28.18 28.13 28.19 29.5 29 28.5 28 sym2 0.01 29.19 29.21 29.18 29.14 29.22 27.5 0.02 27.60 27.63 27.60 27.67 27.70 27 0.03 27.09 27.06 27.07 27.07 27.06 0.04 26.81 26.82 26.84 26.88 26.86 26.5 sym10 0.05 26.72 26.73 26.71 26.73 26.71 28.58 28.61 28.62 28.57 28.59 26 sym20 0.01 0.02 28.28 28.30 28.28 28.29 28.28 0.03 28.12 28.16 28.17 28.15 28.15 0.04 28.06 28.10 28.08 28.07 28.07 0.05 28.00 28.06 28.01 28.03 28.02 0.01 28.52 28.51 28.50 28.56 27.87 0.02 28.17 28.13 28.51 28.15 28.49 0.03 27.99 27.96 28.00 28.00 28.15 0.04 27.95 27.91 27.91 27.92 27.99 0.05 PSNR (in DB) 27.89 27.86 27.85 27.85 27.87 Car Horse sym5 25.5 25 0.01 0.04 0.02 0.05 0.03 0.01 0.04 Globe sym3 Fig. 4. Graphical performance of Coiflet family TABLE 4 Waveletfamily Coiflet Organized By: GNI Nagpur, India International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) Rose Globe Car Horse Variance coif1 coif2 coif3 coif4 coif5 0.01 28.69 28.83 28.69 28.71 28.74 0.02 28.40 28.43 28.38 28.39 28.39 0.03 28.30 28.30 28.26 28.27 28.25 0.04 28.20 28.19 28.19 28.20 28.23 0.05 28.10 28.20 28.13 28.17 28.19 0.01 29.20 29.16 29.14 29.20 29.19 0.02 27.65 27.66 27.63 27.71 27.70 0.03 27.04 27.06 27.08 27.08 27.06 0.04 26.86 26.85 26.86 26.81 26.85 0.05 26.74 26.72 26.72 26.71 26.73 0.01 28.58 28.59 28.61 28.56 28.58 0.02 28.30 28.26 28.26 28.26 28.29 0.03 28.13 28.15 28.15 28.14 28.13 0.04 28.10 28.08 28.06 28.10 28.03 0.05 28.02 28.03 28.02 28.03 28.02 0.01 28.50 28.53 28.49 28.55 28.53 0.02 28.11 28.13 28.16 28.16 28.13 0.03 27.97 28.02 27.97 28.01 27.97 0.04 27.90 28.01 27.92 27.93 27.91 0.05 27.87 27.87 27.84 27.87 27.86 29.5 29 28.5 28 27.5 27 26.5 26 25.5 25 coif1 coif2 coif3 coif4 coif5 0.01 0.04 0.02 0.05 0.03 0.01 0.04 Image Fig. 5 Graphical performance of Coiflet family The visual quality results are shown in figure 2. The images shown here are denoised at the noise varience 0.01 to 0.05 each at decomposition level of 5, which is optimum level of denoising. The results show that wavelet function BIOR2.2 provides better results in terms of PSNR for the test image Globe. Also, it is found that the wavelet function BIOR 2.2 gives better visual quality when the test images are in .png format. Secondly DB4 and DB6 provides better results in terms of PSNR for the test image Rose.jpg. While COIF2 and BIOR2.6 shows the Competitive PSNR performance for the large noise varience for the test images Rose.jpg . The analysis and comparison of the results show that the not only in the BIOR family, the wavelet function BIOR 2.2 gives the better denoising results ( in terms of PSNR) in all the wavelet families considered in our experiment. For the denoising performance in terms of visual image quality, the wavelet BIOR 2.2 provides the better results for the test image. While, the wavelet BIOR 2.6 for the images Bird and Bridge gives the better compression performance in terms of visual image quality .This shows that objective as well as subjective quality of the compressed image is better for wavelet family Biortogonal. Motivation following this performance is that Biorthogonal wavelets can use filters with similar or dissimilar order for decomposition (Nd) and reconstruction (Nr). Therefore Biorthogonal wavelet is parameterized by two numbers and filter length is {max (2Nd, 2Nr) +2} [8]. Also these are Symmetric and Symmetry provides linear phase and minimize border arti-facts. In study if decomposition level is increased the compression performance improves but the quality of image deteriorates. Further, it is also observed that the BIOR wavelet families take much more computational time in comparison to other wavelet families considered in our experiment. Also it is found that as the filter order increases in a given wavelet family, the compression performance increases, but the visual quality of compressed image becomes not as good as. The higher order of filters involves the longer filters, which involves more blurring in the compressed image Organized By: GNI Nagpur, India International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) A)ORIGINAL IMAGE b) DENOISED IMAGE BY DB6(VAR 0.01) & C)DB6 VAR 0.05 D) COIF5, VAR=0.05 F)Denoised by bior2.2 var=0.01G) SYM1,VAR=0.01 H) BIOR 2.6, VAR=0.01 Fig. 6 Visual quality and performance 6. CONCLUSION This analysis focuses on the performance of orthogonal and Biorthogonal mother wavelets for image denoising using Gaussian noise on variety of test images. This paper measures the performance of the images in terms of peak signal to noise ratio and visual quality of the image also. it is found that Biorthogonal wavelets outperform the orthogonal ones in both the criteria. References [1] S. Ruikar and D. D. Doye, “Image Denoising Using Wavelet Transform,” 2010 2nd International Conference on Mechanical and Electrical Technology, Singapore, 10-12 September 2010, pp. 509-515. doi:10.1109/ICMET.2010.5598411 [2] W. R. Tettler, J. Huffman and D. C. P.Linden, “Application of compactly supported wavelets to image compression”, Proceeding SPIE-1244, 1990, pp. 150-160. [3] Usevitch, B. E., 2001. A Tutorial on Modern Lossy Wavelet Image Compression: Foundations of JPEG 2000. IEEE Signal Processing Magazine. [4] Rout, S. 2003. Orthogonal vs Biorthogonal Wavelets for Image Compression. MS Thesis, Virgina Polytechnic Organized By: GNI Nagpur, India International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com ISSN 2319 - 4847 Special Issue for National Conference On Recent Advances in Technology and Management for Integrated Growth 2013 (RATMIG 2013) Institute and State University, Virgina. [5] Hong LIU, Lin-pei ZHAI, Ying GAO, Wen-ming LI, Jui-fei ZHOU, “Image Compression Based on Biorthogonal Wavelet Transform”, IEEE Proceedings of ISCIT, 2005. [6] Veeraswamy, K. and Srinivas, Kumar S. 2008. An Improved Wavelet Based Image Compression Scheme and Oblivious Watermarking. IJCSNS International Journal of Computer Science and Network Security, 8, 170-177. [7] Scott E Umbaugh, Computer Vision and Image Processing, Prentice Hall PTR, New Jersey, 1998. [8] Chin-Chuan Han, Hsu-Liang Cheng, et al. Personal authentication using palm-print features. Pattern Recognition 36 (2003) 371 – 381. [9] Kanvel, T. N. and Monie, E. C. 2009. Performance Measure of Different Wavelets for a Shuffled Image Compression Scheme. IJCSNS International Journal of Computer Science and Network Security, 9, 215-221.221. [10]Matlab 6.1, “Wavelet tool box,” http://www.mathworks.com/access/helpdesk/help/toolbox/wavelet/wavelet .shtml. [11] Kumari, S. et al. 2010. Image Quality Prediction by Minimum Entropy Calculation for Various Filter Banks.’, International Journal of Computer Applications, 7(5), 31-34. [12] C. S. Burrus, R. A. Gopinath and H. Guo, “Introduction to Wavelet and Wavelet Transforms,” Prentice Hall, New Jersey, 1997. Mrs. Reena Thakur has received a B.E.(CSE) degree from Amravati University and Master degree in Computer Science and Engineering from Uttar Pradesh Technical University Lucknow(U.P.). She is having 17 yrs of teaching experience. She has written three books. She has more than 10 publications to her credit in international journals, conferences as well as in IEEE Explore. Her fields of interest are Image Processing, Data Mining, Computer Graphics. She is presently working in Guru Nanak Institute of Engineering and Technology, Nagpur. Organized By: GNI Nagpur, India