Short-working-distance optical imaging system and method for surface detection of underwater structures

In the surface imaging of underwater structures, long working distance will reduce image quality due to the turbidity of water. To acquire high definition and large field of view (FOV) images for surface detection, a short-working-distance underwater imaging system is proposed based on camera array. A multi-view calibration and rectification method is developed. A look-up table (LUT) method and a multi-resolution spline (MRS) method are applied to stitch array images real-time and seamlessly. Experiments both in the air and in the water are conducted. Strength and weakness of the LUT and MRS methods are discussed. Based on the results, the effectiveness in surface detection of underwater structures is verified.