This research work investigates visibility degradation due to poor weather conditions and pro- poses methods to improve the colour, contrast, and visibility of digital images taken under such conditions. It is common knowledge that digital images need post processing not only for better human perception but also to be fed as input to computer vision application systems. Visibility improvement is a process of restoring the true appearance, i.e. recovering what the scene should have looked like on a clear day, by enhancing the colour, contrast and sharpening the details. Amongst the ample...