On the way to solve lighting problems in underwater imaging

R. Garcia, T. Nicosevici, X. Cufi
Oceans '02 MTS/IEEE  
A major obstacle to processing images of the ocean floor comes from the absorption and scattering effects of the light in the aquatic environment. Due to the absorption of natural light, underwater vehicles often require artificial light sources attached to them to provide the adequate illumination. Unfortunately, these flashlights tend to illuminate the scene in a nonuniform fashion, and, as the vehicle moves, induce shadows in the scene. For this reason, the first step towards application of
more » ... rds application of standard computer vision techniques to underwater imaging requires dealing first with these lighting problems. This paper analyses and compares existing methodologies to deal with lowcontrast, nonuniform illumination in underwater image sequences. The reviewed techniques include: (i) study of the illumination-reflectance model, (ii) local histogram equalization, (iii) homomorphic filtering and (iv) subtraction of the illumination field. Several experiments on real data have been conducted to compare the different approaches.
doi:10.1109/oceans.2002.1192107 fatcat:jcqz5gfubzgw3em3ei3valwgte