Removal of ladder effects by smoothening the integer format elevation layer via development of a QGIS plugin

Digital elevation model (DEM) images present the elevation information of earth's surface in the form of an image in floating point or integer format. While integer type has substantial space saving capabilities, they show stair-case or ladder effect when an image is draped on DEM using 3D visualization software. Due to wide availability of DEM data in integer format, it becomes imperative to develop a utility to convert the data in floating point format to reduce the staircase effect. The open source capabilities of QGIS provide an ideal platform to develop such plugins with ease. Quantum GIS is a free, open source, cross platform GIS-application software having vast repository of free plugins. Its functionality can be extended by developing plugins in C++/ Python language. Comparison of the resultant image with the parent DEM image shows a significant improvement in reducing the staircase effect.