IMAGE QUALITY IMPROVEMENTS IN LOW-COST UNDERWATER PHOTOGRAMMETRY
Keywords: underwater photogrammetry, image quality, action cameras, GoPro, accuracy evaluation, 3D modelling
Abstract. This study presents an evaluation of a cheap consumer-grade camera used for modelling a coral reef section. We evaluate the quality of a reconstructed coral reef using GoPro cameras and a high-end camera with data from an actual coral reef dataset. We also investigate components of the processing pipeline (like image quality) separate from the final results. Because our GoPro images suffer from severe chromatic aberration, we apply different image pre-processing steps to improve their quality and show its effects on the reconstructed object points. Bundle adjustment is carried out as free networks in all cases, with a follow-up rigid 3D Helmert transformation onto a geodetic control network, carried out to define the common datum and to remove the bias from the free network results.