Automatic Control for Adaptive Lighting System for Underwater Photogrammetry Image Acquisition

Underwater photogrammetry has been used for multiple applications in research, analysis and entertainment activities. It allows the generation of three-dimensional (3D) representation of underwater ecosystems, which provides helpful information. In addition, according to technological developments, this technique has become an inexpensive and simple alternative to generate a 3D model. However, underwater photogrammetry has some challenges related to illumination in medium-depth and large-depth zones, and how it influences image quality. Therefore, this paper presents the design and testing of automatic control for an adaptive lighting system. The purpose is to generate adequate illumination over the area of interest and obtain images with optimal illumination, which could allow building better 3D models. From the results, we will analyze the control signal convergence, stabilization time, appearance of the real image and robustness to different values of the control parameters. Particularly, according to the control parameters selected and the considerations over the tests, a 22.5% and 15.3% illumination capacity is required for underwater and ground image acquisition, respectively.