ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. II, Special Issue XXIII, March 2015 in association with FRANCIS XAVIER ENGINEERING COLLEGE, TIRUNELVELI DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN COMMUNICATION SYSTEMS AND TECHNOLOGIES (ICRACST’15) TH 25 MARCH 2015 Reformulated Fuzzy C - means Based Image Segmentation 1 2 3 S.Rajeswari , K.Thulasi , A.Vijayalakshmi , P.Subbalakshmi 4 U.G. Student, Department of Computer Engineering, PSRR Engineering College, Sivakasi,Tamilnadu India. Associate Professor, Department of Computer Engineering, PSRR Engineering College,SivakasiTamilnadu,India4 Abstract – Image segmentation deals with partition of images in to separate constitutes. Fuzzy C-means (FCM) is a hard clustering algorithm. It uses spatial information and enhances their insensitiveness to noise. But it still lacks enough robustness to noise when the absence of prior knowledge of noise. To overcome this, Fuzzy Local Information C-means (FLICM) is introduced. It is independent to noise and free of parameter selection. Here, Reformulated Fuzzy Local Information C-means (RFLICM) is introduced which replaces spatial information by local coefficient of variation. The local coefficient of variation exploits more contextual information when compared to spatial information. Simulations on the segmentation of synthetic and medical images demonstrate the robustness and advantages of RFLICM algorithm. Performances of medical image is found by means of Segmentation accuracy . Index Terms - FCM, FLICM, RFLICM, Spatial information, Segmentation accuracy. I. INTRODUCTION Fuzzy clustering plays an important role in solving problems in the areas of pattern recognition and fuzzy model identification. A variety of fuzzy clustering methods have been proposed and most of them are based upon distance criteria [3]. One widely used algorithm is the Fuzzy C-Means (FCM) algorithm. It uses reciprocal distance to compute fuzzy weights. Fuzzy c-means (FCM) is one of the most promising fuzzy clustering methods [3]. Clustering, particularly fuzzy C-means (FCM)-based clustering and its variants, have been widely used in the task of image segmentation due to their simplicity and fast convergence [1] [4], [6] [10] - [12]. By carefully selecting input features such as pixel color, intensity, texture, or a weighted combination of these data, the FCM algorithm can segment images to several regions in accordance with resulting clusters [1]. In most cases, it is more flexible than the corresponding hard clustering algorithms. It is effective for spherical clusters; it does not perform well for more general clusters. The FCM algorithm has also been extended to the kernel FCM algorithm, which yields better performance. However, for such kernel-based methods, a crucial step is the combination or selection of the best kernels among an extensive range of possibilities [3]. Recently, the FCM and other clustering based image segmentation approaches use the local spatial information of pixels in classical clustering procedures[1] [4] [6]. Because of the local spatial information, the new FCM algorithm has demonstrated robustness over noises in images [1] [4]. In addition to the incorporation of local spatial information, the FCM has made an improvement in their performance. Clustering is performed on the basis of the gray level histogram of the summed image. However, this FCM do not directly apply on the original image. They need some parameters a (or λ) to control the trade-off between robustness to noise and effectiveness of preserving the details. The selection of these parameters is not an easy task, and has to be made by experience or by using the trial-and-error 257 All Rights Reserved © 2015 IJARTET ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. II, Special Issue XXIII, March 2015 in association with FRANCIS XAVIER ENGINEERING COLLEGE, TIRUNELVELI DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN COMMUNICATION SYSTEMS AND TECHNOLOGIES (ICRACST’15) TH 25 MARCH 2015 method. To overcome the above mentioned problems, Stelios et al.[5] presents a novel robust fuzzy local information c-means clustering algorithm (FLICM), which is free of any parameter selection, as well as promoting the image segmentation performance. In FLICM, a novel fuzzy factor is defined to replace the parameter a used in above algorithms and its variants [2]. In order to overcome the above mentioned disadvantages a new factor in Fuzzy C Means objective function is needed. The new factor should have some special characteristics such as, • Incorporate local spatial and local gray level information in a fuzzy way in order to preserve robustness and noise insensitiveness. • Control the influence of the neighborhood pixels depending on their distance from the central pixel. • Use the original image avoiding preprocessing steps that could cause detail missing . So, Reformulated Fuzzy Local Information C-means (RFLICM) is proposed, which adopts the local coefficient of variation to replace the spatial distance as a local Similarity measure. Furthermore, it presents a more robust result. Although RFLICM algorithm can exploit more local context information to estimate the relationship of pixels in neighbors [3] [7]. II. FLICM (Fuzzy Local Information C-Means) The conventional FCM algorithm[8] [9] works well on noise free images, but it is fails to segment images ruined by noise and other image relics. This algorithm has the drawback of producing the non-robust result because of the ignorance of the spatial contextual information in an image and the use of the non- robust Euclidean distance. In order to overcome these problems, a novel robust fuzzy local information cmeans clustering (FLICM) is introduced which overcomes the problem of parameter selection a and also promotes the image segmentation performance. It determines the spatial and gray level relationship that is free of any parameter selection. The FLICM algorithm has some attractive characteristics like (a) it is independent of the type of noise and is free of any parameter selection. (b) It incorporates both the local spatial and the local gray level relationship simultaneously in a fuzzy way. (c) The fuzzy local constraints are automatically determined; hence there is no need for any parameter selection. (d) The clustering performance is enhanced concurrently by balancing the image details and noise. This is achieved automatically by using fuzzy local constraints. (e) It controls the influence of the neighborhood pixels based on their distance from the central pixel. (f) Uses the original image avoiding the preprocessing steps which could cause the missing of the image details [8]. The objective function is termed as J N m c [u || x v m . ki i 1 k 1 i k || 2 G ki ] (4) The parameter m is a weighting exponent on each fuzzy membership and determines the amount of fuzziness of the resulting classification. Here, we set m = 2 for the following experiments. The fuzzy factor G ki is defined mathematically as follow, G d N ki j i 1 ij 1 u || x v || m 1 kj j 2 k (5) where the ith pixel x i is the center of the local window and the jth pixel x j represents the neighboring pixels falling in to the window around x i , d ij is the spatial Euclidean distance between pixels i and j . N i stands for the set of neighbors in a window around x i . v k represents the prototype of the center of cluster k, and u kj represents the fuzzy membership of gray value x j with respect to the kth cluster. The two necessary conditions with respect to Uki and Vk u ki 1 || || || x v || G x v G c j 1 2 i k 2 i j 1 m 1 (6) ki ji 258 All Rights Reserved © 2015 IJARTET ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. II, Special Issue XXIII, March 2015 in association with FRANCIS XAVIER ENGINEERING COLLEGE, TIRUNELVELI DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN COMMUNICATION SYSTEMS AND TECHNOLOGIES (ICRACST’15) TH 25 MARCH 2015 N v k m ki u i 1 N u i1 x m ki jN i i (7) u u b=b+1 and go to step 4. The advantage of the FLICM algorithm is that the objective function is automatically determined even in the absence of prior noise knowledge. III. RFLICM (Modified Fuzzy Local Information C-Means) Reformulated Fuzzy Local Information c-means clustering (RFLICM) algorithm, which implements the local coefficient of variation to replace the local spatial distance as a local similarity measure. In accordance with the fuzzy factor G ki , it is conditional that the local gray level information and spatial information in G ki are represented by the gray-level difference and spatial distance respectively. The local spatial relationship changes adaptively according to spatial distances from the central pixel. The local coefficient of variation is defined as, c u var x x2 (8) Where varx and x are the intensity variance and the mean in a local window of the image, respectively. 2 min *1 G ki The FLICM algorithm is given as follows: 1)Set the number c of the cluster prototypes, fuzzification factor m and the stopping condition ε. 2) Initialize randomly the fuzzy partition matrix. 3) Set the loop counter b=0. 4) Calculate the cluster prototypes using (6). 5) Compute the membership values using (7). b b 1 < ε then stop, otherwise, set 6) If max 1 j Ni u m || kj j , u 2 c c c c u / x v j k u || 2 , if / 2 j u j c c u u 1 2 min * 1 u m || kj j , u 2 c c c c u / x v j k u || 2 , if / (9) 2 j u j c c u u Where Cu represents the local coefficient of variation of central pixel. c uj represents the j th local coefficient of variation in neighbours, c u is the mean value of c uj that is located in a local window. The fuzzy factor G’ki balances the membership value of the central pixel by considering the local coefficient of variation and the gray level of the neighbouring pixels. When there is a difference between the results of the local coefficient of variation that are obtained by the neighbouring pixels are different, the weightings added to the neighbouring pixel in G’ki will be increased to suppress the influence of outlier, which is expected to be more robust [8]. The RFLICM algorithm is given as follows: 1) Set the number c of the cluster prototypes, fuzzification factor m and the stopping condition ε. 2) Initialize randomly the fuzzy partition matrix. 3) Set the loop counter b=0. 4) Calculate the cluster prototypes using (6). 5) Compute the membership values using (7). b b 1 < ε then stop, otherwise, set 6) If max u u b=b+1 and go to step 4. RFLICM algorithm can exploit more local context information to estimate the relationship of pixels in neighbors. V. RESULTS AND DISCUSSION 259 All Rights Reserved © 2015 IJARTET ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. II, Special Issue XXIII, March 2015 in association with FRANCIS XAVIER ENGINEERING COLLEGE, TIRUNELVELI DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN COMMUNICATION SYSTEMS AND TECHNOLOGIES (ICRACST’15) TH 25 MARCH 2015 In this section the algorithms were run on a computer system. All the programs were written in mat lab and run under Windows XP (64 bit) operating system. Both the images consist of 256 × 256 pixels and include two classes with two intensity value taken as 20 and 120, as shown in Fig. 1(a). The number of clusters is 2. The algorithms (FLICM, and RFLICM) are tested on the images corrupted by Salt & Pepper noise. In our numerical experiments, we generally choose ε = 0.001 [8]. Also the RFLICM algorithm is compared with FLICM. The RFLICM algorithm can detect the clusters of an image overcoming the disadvantages of the FCM based clustering techniques.The below are the simulation results for Brain tumour image using the Clustering techniques like FLICM,RFLICM. (a) Fig. 1. Segmentation results on the Brain tumour image corrupted by Salt & Pepper noise (15%). (a) Original image. (b) Noisy image. (c) Enhanced Image.(d) FLICM result. (a) (b) (c) (d) (b) Fig. 2. Segmentation results on the Brain tumour image corrupted by Salt & Pepper noise (15%). (a) Original image. (b) Noisy image. (c) Enhanced Image. (d) RFLICM result. (c) (d) 260 All Rights Reserved © 2015 IJARTET ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. II, Special Issue XXIII, March 2015 in association with FRANCIS XAVIER ENGINEERING COLLEGE, TIRUNELVELI DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN COMMUNICATION SYSTEMS AND TECHNOLOGIES (ICRACST’15) TH 25 MARCH 2015 VI. PERFORMANCE MEASURES FCM based clustering techniques are compared by means of Segmentation accuracy. It can be defined as the number of correctly classified pixels divided by total number of pixels. FLICM, RFLICM Algorithms are compared by means of features like SA Segmentation accuracy deals with how well the image is segmented. From the tabulation it is clearly found that RFLICM is the best when compared with FLICM. SA= number of classified pixels Total number of pixels Table.1.Comparison of Segmentation accuracy, PSNR for Brain tumour Image Algorithm FLICM RFLICM Segmentation Accuracy 93.18 97.07 VII. CONCLUSION In this paper FCM based clustering techniques are used to identify the tumor in the human brain.FCM has some limitations, that is, it wrongly classifies the noisy pixels in the medical images and has incorrect membership and improper segmentation for noisy images. To overcome that, FLICM with fuzzy factor is introduced which includes spatial and gray level information. Here, RFLICM (Reformulated Fuzzy Local Information C-Means) Algorithm is used which replaces spatial information by local coefficient of variation can exploit more contextual information. Features like Segmentation Accuracy is calculated using Matlab coding and the above two algorithms are compared. Simulation results show that the RFLICM Algorithm gives better results. The results were tabulated and compared. IX. REFERENCES [1].Long Chen, C. L. Philip Chen, Fellow, IEEE, and Mingzhu Lu, Student Member, IEEE, “ A Multiple Kernel Fuzzy C-means Algorithm for Image Segmentation ,” IEEE Transaction on System,Man, and Cybernatics., Feb 2011. [2].Maoguo Gong, Member, IEEE, Yan Liang, Jiao Shi, Wenping Ma, and Jingjing Ma, “Fuzzy C-Means Clustering With Local Information and Kernel Metric for Image Segmentation“IEEE Transactions on Image Processing, Vol. 22, No. 2, February 2013. [3].Mrs.K.Arun Prabha, P.Malini,“An Efficient Algorithm for Clustering of Images using Fuzzy Local Information C Means“The Int. Journal of Computer ISSN–2278--‐1080,Vol.1 Science & Applications No.11,January 2013. [4]. W. L. Cai, S. C. Chen, and D. Q. Zhang, “Fast and robust fuzzy c-means clustering algorithms incorporating local information for image segmentation,” Pattern Recognit., vol. 40, no. 3, pp. 825– 838, Mar. 2007. [5] .S. Krinidis and V. Chatzis, “A robust fuzzy local information C-means clustering algorithm,” IEEE Trans. Image Process., vol. 19, no. 5, pp.1328–1337, May 2010. [6] K. Sikka, N. Sinha, P. K. Singh, and A. K. Mishra, “A fully automated algorithm under modified FCM framework for improved brain MR image segmentation,” Magn. Reson. Imaging, vol. 27, no. 7, pp. 994–1004, Sep. 2009. [7].M. Gong, Z. Zhou, and J. Ma, “Change detection in synthetic aperture radar images based on image fusion and fuzzy clustering,” IEEE Trans. Image Process., vol. 21, no. 4, pp. 2141–2151, Apr.2012. [8].B.Vinodhini, “Survey on Clustering Algorithms“International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 2, Issue 6, November 2013. [9].L. Szilagyi, Z. Benyo, S. Szilagyii, and H. Adam, “MR brain image segmentation using an enhanced fuzzy C-means algorithm,” in Proc. 25th Annu. Int. Conf. IEEE EMBS, Nov. 2003, pp. 17–21. 261 All Rights Reserved © 2015 IJARTET ISSN 2394-3777 (Print) ISSN 2394-3785 (Online) Available online at www.ijartet.com International Journal of Advanced Research Trends in Engineering and Technology (IJARTET) Vol. II, Special Issue XXIII, March 2015 in association with FRANCIS XAVIER ENGINEERING COLLEGE, TIRUNELVELI DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN COMMUNICATION SYSTEMS AND TECHNOLOGIES (ICRACST’15) TH 25 MARCH 2015 [10].S. P. Chatzis and T. A. Varvarigou, “A fuzzy clustering approach toward hidden Markov random field models for enhanced spatially constrained image segmentation,” IEEE Trans. Fuzzy Syst., vol. 16, no. 5, pp. 1351–1361, Oct. 2008. [11] M. A. Jaffar, N. Naveed, B. Ahmed, A. Hussain, and A. M. Mirza, “Fuzzy C-means clustering with spatial information for color image segmentation,”in Proc. 3rd Int. Conf. Elect. Eng., Lahore, Pakistan, Apr. 2009,pp. 136–141. [12] K. S. Chuang, H. L. Tzeng, S. Chen, J. Wu, and T. J. Chen, “Fuzzy c-means clustering with spatial information for image segmentation,” Comput. Med. Imaging Graph., vol. 30, no. 1, pp. 9–15, Jan. 2006. 262 All Rights Reserved © 2015 IJARTET
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