Spectral Subtraction for Image Denoising

This code will add Gaussian noise to an image and denoise it using SSD technique.

This code will add Gaussian noise of a given std.deviation to an image and denoise it using SSD(Spectral Subtraction Denoising)technique.It will plot the psd of original,noisy and denoised images.The code can be run without the noise std.deviation(sigma) information.In that case you have to comment/uncomment the necessary portions which is stated in the code & give some arbitrary sigma(sigma=10).