Image Resolution and Contrast Enhancement of Satellite Geographical Images with Removal of Noise using Wavelet Transforms

摘要

In this paper the technique for resolution and contrast enhancement ofsatellite geographical images based on discrete wavelet transform (DWT),stationary wavelet transform (SWT) and singular value decomposition (SVD) hasbeen proposed. In this, the noise is added in the input low resolution and lowcontrast image. The median filter is used remove noise from the input image.This low resolution, low contrast image without noise is decomposed into foursub-bands by using DWT and SWT. The resolution enhancement technique is basedon the interpolation of high frequency components obtained by DWT and inputimage. SWT is used to enhance input image. DWT is used to decompose an imageinto four frequency sub bands and these four sub-bands are interpolated usingbicubic interpolation technique. All these sub-bands are reconstructed as highresolution image by using inverse DWT (IDWT). To increase the contrast theproposed technique uses DWT and SVD. GHE is used to equalize an image. Theequalized image is decomposed into four sub-bands using DWT and new LL sub-bandis reconstructed using SVD. All sub-bands are reconstructed using IDWT togenerate high resolution and contrast image over conventional techniques. Theexperimental result shows superiority of the proposed technique overconventional techniques. Key words: Discrete wavelet transform (DWT), General histogram equalization(GHE), Median filter, Singular value decomposition (SVD), Stationary wavelettransform (SWT).