A novel blending technique for two-dimensional forward-looking sonar mosaicing

High-resolution forward-looking sonars are becoming a tool of choice for exploring underwater environments under low visibility conditions. Their imagery can be mosaiced to obtain a global overview of submerged areas of interest and the spatial arrangement of different target features. However, in order to achieve an informative and smooth image composition, the individual sonar frames must be fused. Unlike the blending in optical mosaics, this implies dealing with a high number of overlapping images as well as with sonar specific artifacts arising from its image formation geometry. This work presents a novel blending pipeline designed to cope with these artifacts involving strategies to diminish the impact of all the photometric irregularities that might be present when mosaicing forward-looking sonar imagery. Results of blended mosaics, including data gathered with different sonar models and presenting several artifacts, are presented here to show the applicability of the method.