Adaptive fractional differential approach to enhance underwater images

The visibility of the underwater images is highly affected by two major sources of distortion i.e., light scattering and colour change. The multiple reflection and deflection by particles present in the water cause a decrement in visibility and contrast of the image captured by the camera. Distinct attenuation in different component of colour (R, G, B) consequences the colour change in the image. In this paper, a novel systematic approach based on a fractional filter has been used to enhance the low contrast underwater image. The order of the fractional derivative has been chosen adaptively, which largely depends on the presence of the weak and strong edges. Depending upon the amount of attenuation to each light wavelength, the colour change is compensated in order to restore the colour information. The results obtained demonstrate that there is a significant improvement in visibility and colour fidelity. The result has been compared with some state-of-the-art technique and it is observed that the results obtained are at most comparable to the existing technique.