Satellite image enhancement techniques — A comparative study

Satellite Images are used nowadays in multiple applications. Generally these Images are very noisy and blurry. This paper presents comparison of different techniques for contrast enrichment on the basis of their PSNR values. In the method proposed by us, for removal of noise and blur different instinctive procedure suggested for pre-processing and it also lowers the consequence of blur and noise. Contrast improvement is being aided by the universal data content of an image by enlarging the dynamic variety of intensity levels, utilized by Conversion functions. Fuzzy based enhancement is also applied to improve the image. To focus adequate details within an image Sharpening filters, based on first and second order derivative, are used. Whereas the other contrast enrichment method, proposed earlier, utilized M-band wavelet transform and singular value decomposition. M-band wavelet transform used to decompose the images into one low frequency and fifteen high frequency sub-bands and approximates the singular value matrix of the sub-band with low frequency, and, then inverse transform is used to restructure the improved image. The output result by all techniques is compared on the basis of their corresponding PSNR values.