| To improve the statistical accuracy of seabed polymetallic nodule coverage, a morphological reconstruction algorithm is proposed as an optimized method in post-image processing. In the experiment, the methods of grid-counting, image binaryzation and morphological reconstruction are carried out to compute and analyze the coverage of the seabed polymetallic nodule images taken by the “Jiao long” manned deep-sea research submersible. As a result, the traditional artificial grid-counting method is proved to have the shortcomings of big workload, time consumption and unstable statistical errors. In contrast, the image binaryzation method can greatly improve the efficiency and accuracy of the statistical work, however, this method couldn’t avoid some statistical errors, resulting in low values generated from the cover of some obstacles, such as soft mud and gravels, on the surface of polymetallic nodules. The optimized algorithm can extract the threshold automatically and fill the covered areas. The shortcomings of the other two methods are thus compensated, achieving satisfying efficiency and accuracy. |
