Int. J. Communications, Network and System Sciences, 2012, 5, 624-630 doi:10.4236/ijcns.2012.529072 Published Online September 2012 (http://www.SciRP.org/journal/ijcns) A Hybrid Method for Edge Continuity Based on Pixel Neighbors Pattern Analysis (PNPA) for Remote Sensing Satellite Images Waqas Haider, Muhammad Sharif Malik, Mudassar Raza, Abdul Wahab, Izhar Ahmed Khan, Umar Zia, Jawad Tanveer, Hadia Bashir Department of Computer Science, COMSATS Institute of Information Technology, Wah Cantt and Vehari Campus, Islamabad, Pakistan Email: waqasbtn@gmail.com, muhammadsharifmalik@yahoo.com, mudassarr@gmail.com, abdulwahab86@gmail.com, izhar_khan43@yahoo.com, muftiumar@yahoo.com, comsats8@gmail.com, hadia_ciit@yahoo.com Received June 25, 2012; revised July 26, 2012; accepted August 7, 2012 ABSTRACT Edge enhancement is derived from lack of accurate result from edge detection techniques. The image which is captured from long distances carries a lot of noise and blur which causes edge discontinuity. Although some novel algorithms which are based on cellular neural network, fuzzy enhancement and binary morphology have shown accuracy in order to obtain refined edge but still the problem of edge discontinuity arises. Eliminating discontinuity of edge a hybrid technique is proposed based on pixel neighbors pattern analysis PNPA. In the technique Canny operator for initial edge detection, PNPA operation for edge enhancement are performed for remote sensing satellite image successively. The visual and subjective evaluation shows that the proposed PNPA operation can effectively eliminate the influence of edge discontinuity which occurred due to noise and blurr in original captured image, as comparing to existing edge segmenting processes. Keywords: Edge Detection; Edge Enhancement 1. Introduction Segmenting regions in an image applies frequently the operations for determining edges of regions. In many image processing applications, preserving edges of im- ages is important. Edge is the set of pixels which de- scribes the boundary of any region of the image. As in- side an image there may be different regions or multiple structures so edge describes each structure’s boundary. The image which is captured from long distance carries noise which causes burred image which ultimately in- duced discontinuity in edge of that image [1,2] when edge is detected with traditional edge detection operators. Several contributors demonstrated there work in the area of edge detection of remote sensing images which are given in [3-10]. In remote sensing satellite image there are multiple structures in it like roads, fields, rivers, for- est buildings and residential areas. Accurate boundary segmentation of such parts in an image totally based on edge detection and edge enhancement. Edge enhance- ment is a method of image segmentation in which the detected edge should be continuous. But it is an issue which has not been resolved completely so far because in such images which are captured from long distances, the illumination and noise factors are high which causes edge discontinuity. In this research, discontinuity of edge lines are tried to minimize with proposed hybrid edge enhancement tech- nique PNPA, which is expressed briefly in Section 4 of the paper. The rest of this paper is organized as follows. Section 2 reviews the existing work in the domain of edge enhancement and edge continuity. Section 3 reviews the working and merits/demerits of edge detection operators. Section 4 describes the proposed method (e.g. PNPA) for edge continuity. In Section 5, the comparative evaluation of visual and subjective results are given and finally in Section 6, the discussion and conclusion are given. 2. Existing Work in the Domain of Edge Enhancement Acquiring edge continuity has been addressed by differ- ent new novel techniques which are based on cellular neural network [2] and binary morphology [3] proved better edge quality but the operators which are based on mathematical morphology are not effective for images which have too many ramp edges [11]. In [12] the suit- able strategies are expressed for edge thickness and dis- Copyright © 2012 SciRes. IJCNS