Edges Detection Based On Renyi Entropy with Split/Merge

Most of the classical methods for edge detection are based on the first and second order derivatives of gray levels of the pixels of the original image. These processes give rise to the exponential increment of computational time, especially with large size of images, and therefore requires more time for processing. This paper shows the new algorithm based on both the Rényi entropy and the Shannon entropy together for edge detection using split and merge technique. The objective is to find the best edge representation and decrease the computation time. A set of experiments in the domain of edge detection are presented. The system yields edge detection performance comparable to the classic methods, such as Canny, LOG, and Sobel.  The experimental results show that the effect of this method is better to LOG, and Sobel methods. In addition, it is better to other three methods in CPU time. Another benefit comes from easy implementation of this method. Keywords: Rényi Entropy, Information content, Edge detection, Thresholdin

An exploratory investigation of low-altitude aerial image acquisition for land surface studies

In the context of environmental monitoring and sustainable land management this thesis seeks to evaluate the application of low-altitude remote sensing from a DIY perspective in the lower Ashburton River catchment. It seeks to demonstrate that the innovative synergistic use of airborne digital videography and CIR (colour infrared) 35mm photography can provide near real-time photomapping at local levels. These technologies are relatively inexpensive, easy-to-use and have proven successful in other countries. Used together with Desktop software systems for image processing, measurement and spatial calibration one can fulfil many community based environmental monitoring and sustainable land use management tasks. The concept of sustainable land use also implies we have an understanding of the landscape processes past and present that have occurred in the region. This is assessed using historical documents so that we may better appreciate the pace of rapid transformation. The role of GPS technology for the georeferencing of selected images into a GIS system is evaluated. The potential adoption of environmental monitoring index systems developed in Australia and Canada is investigated which would rely partly on the proposals recommended in this study