Pavement crack identification method based on point cloud-RGB (Red, Green, Blue) heterogenous image multistage registration mapping

The invention relates to a pavement crack identification method based on point cloud-RGB (Red, Green and Blue) different-source image multistage registration mapping. The method comprises the steps of collecting pavement point cloud data and pavement image data for time and space synchronization, creating a projection image pair for feature extraction, obtaining a local feature descriptor, extracting feature points in the local feature descriptor for matching, obtaining an actual matching point pair, solving parameters of a direct linear transformation equation according to the actual matching point pair, and obtaining a direct linear transformation result. The method comprises the steps of obtaining a mapping relation between RGB image pixel coordinates and three-dimensional point cloud coordinates, traversing coordinates of each point in road surface image data, assigning a mapping relation depth information value to the road surface image data, obtaining a point cloud projection image, generating a depth i