Noise Reduction is an important block in the image processing system. The main problem in image processing is to find the suitable method for reducing noise presented in the captured image. The extent of noise reduction is directly proportional to the quality of the image produced. In this paper, we introduce some basic noise types, traditional noise reduction methods and a proposed method to reduce the Gaussian, Salt and Pepper noise from the PGM images. The proposed methodology discussed here is specially developed to reduce impulse noises efficiently than average or median filter. There are various methods for enhancing the image that is degraded by noise like average filter, median filter and fuzzy filter. This paper is based on the enhanced average filter that gives better result than simple average filter.

1. Lan Huang, Chiou-Shann Fuh ;Noise Reduction Using Enhanced Bilateral Filter ,Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan, 10617, R. O. C,2006,vol 12,No 4.
2. Dimitri Van De Ville, Dietrich Vander Weken, Etienne E. Kerre, Wilfried Philips,and Ignace Lemahieu ,Noise Reduction by Fuzzy Image Filtering; IEEE Transactions On Fuzzy Systems, Vol. 11, No. 4, August 2003.
3. Jagadish H. Pujar,Robust Fuzzy Median Filter for Impulse Noise Reduction of Gray Scale Images, World Academy of Science, Engineering and Technology 40 2010.
4. Jaspreet Kaur,Salt & Pepper Noise Removal using Fuzzy Based Adaptive Filter;International Journal of Science, Engineering and Technology Research (IJSETR) Volume 1, Issue 1, July 2012.
5. R C Gonzales and R E Woods, Digital Image Processing, 2nd ed. Reading, MA: Addison –Wesley, 2002.
6. C. Tomasi, R. Manduchi, "Bilateral Filtering for Gray and Color Images," Proceedings of International Conference on Computer Vision, Bombay, pp. 839-846, 1998.
7. R. C. Gonzalez and R. E. Woods, Digital Image Processing, 2nd Ed. , Prentice-Hall, Upper Saddle River, NJ,2002.
8. D. Van De Ville, W. Philips, and I. Lemahieu, Fuzzy Techniques in Image Processing. New York: Springer-Verlag, 2000, vol. 52, Studiesin Fuzziness and Soft Computing, ch. Fuzzy-based motion detectionand its application to de-interlacing, pp. 337–369.
9. F. Russo and G. Ramponi, "A fuzzy operator for the enhancement of blurred and noisy images," IEEE Trans. Image Processing, vol. 4, pp. 1169–1174, Aug. 1995.
10. C. -S. Lee and Y. -H. Kuo, Fuzzy Techniques in Image Processing. New York: Springer Verlag, 2000, vol. 52, Studies in Fuzziness and Soft Computing, ch. Adaptive fuzzy filter and its application to image enhancement, pp. 172–193.
11. Shyam Lal1, Sanjeev Kumar 2and Mahesh Chandra3:Removal of High Density Salt & Pepper Noise Through Super Mean Filter for Natural Images. 1ECE Department, Moradabad Institute of Technology, Moradabad-244001(UP), India 2,3, ECE Department, Birla Institute of Technology,Mesra,Ranchi-835215(JH),India.
12. An Improved Adaptive Median Filtering Method for Impulse Noise Detection Mamta Juneja,Rajni Mohana Computer Science and Engineering Department Rayat and Bahara Institute of Engineering and Technology (RBIEBT).

Noise Reduction Images Pgm Images.