Analysis of Image Quality using LANDSAT 7 ETM+ and Gaussian Filter

Abstract

Interpretation of image contents is a significant objective in computer vision and image processing. An image contains different information of scene, such as objects shape, size, color and orientation, but discrimination of the objects from their background is the first essential task that should be performed before any interpretation. Filters re-evaluate the value of every pixel in an image. For a particular pixel, the new value is based on pixel values in a local neighborhood, a window centered on that pixel, in order to reduce noise by smoothing and enhance edges. At the same time as reducing the noise in a signal, it is important to preserve the edges. Edges are of critical importance to the visual appearance of images. So, it is desirable to preserve important features, such as edges, corners and other sharp structures, during the denoising process. In this paper an attempt is made to assess the impact of bandwidth on image quality using Gaussian filter and LANDSAT 7 ETM+ satellite imagery. The study area considered for the experimentation is the Mysore city in the state of Katnataka. From the experimental observations, for a satellite image with high resolution around 30m, the window 5x5 is recommended which improves image while preserving the edges.