The studies of the distance-measuring of underwater obstructions by using the image processing technique

The purpose of the present study is to install the distance-measuring module based on the image processing technique with laser instrument to estimate the distance of the expected object. The previous image distancemeasuring technique usually adopted the stereo image method which needs more than two cameras. In order to reduce the cost and avoid the installation errors between two cameras, the present study applies the single camera to estimate the distance and the point or line laser light is also integrated in the system. When the distance of the object changes, the position of the laser light on the object also changes, consequently the distance of the object can be estimated based on this principle. From the test results, we find that the module developed in the study can be applied to be not only in the air but also in the water, which is helpful to the underwater obstacle-avoidance technique in the future.