Blind Separation in Low Frequencies Using Wavelet Analysis, Application to Artificial Vision

We propose a method for image enhancement in colour word when a scattering environment reduces the vision. The main advantage of blind technique is that it does not require any a priori information about the scattering environment but supposes that the observed signals are linear mixtures of sources. Here, the natural logarithm of the degraded image provides an approximative additive mixture of reflectivity and transmittivity coefficients, the colour images provide three coloured mixtures (red, green, blue). They are processed by a Blind Source Separation (BSS) method in low spatial frequencies to display gray levels of pertinent features, which help one to vision enhancement. To display a cleaner vision, the set of mixtures is enriched thanks to classical signal processing technique. The chrominance information is restituted using post-processing techniques on HSV (Hue, Saturation, Value) space of degraded colour image. Experiments are made on images for which scattering environment is simulated in the laboratory. KeywordsScattering environment, Artificial vision, Blind Source Separation, Second order blind identification, Independent component analysis, Wavelet denoising