Enhancement of dark and low‐contrast images using dynamic stochastic resonance

In this study, a dynamic stochastic resonance (DSR)‐based technique in spatial domain has been proposed for the enhancement of dark‐ and low‐contrast images. Stochastic resonance (SR) is a phenomenon in which the performance of a system (low‐contrast image) can be improved by addition of noise. However, in the proposed work, the internal noise of an image has been utilised to produce a noise‐induced transition of a dark image from a state of low contrast to that of high contrast. DSR is applied in an iterative fashion by correlating the bistable system parameters of a double‐well potential with the intensity values of a low‐contrast image. Optimum output is ensured by adaptive computation of performance metrics – relative contrast enhancement factor ( F ), perceptual quality measures and colour enhancement factor. When compared with the existing enhancement techniques such as adaptive histogram equalisation, gamma correction, single‐scale retinex, multi‐scale retinex, modified high‐pass filtering, edge‐preserving multi‐scale decomposition and automatic controls of popular imaging tools, the proposed technique gives significant performance in terms of contrast and colour enhancement as well as perceptual quality. Comparison with a spatial domain SR‐based technique has also been illustrated.