Multi-source point cloud data registration method and system based on different scales

The invention relates to the technical field of photogrammetry, and particularly discloses a multi-source point cloud data registration method based on different scales, and the method comprises the steps: obtaining a laser point cloud and an image point cloud of a target object; processing the image point cloud of the target object to obtain a dense image point cloud of the target object; performing coarse registration on the dense image point cloud to a coordinate system of the laser point cloud according to a 4PCS algorithm added with a scale factor so as to complete coarse registration of the dense image point cloud and the laser point cloud, and obtaining coarse registration parameters at the same time; and according to the dual quaternion space descriptor, the dense image point cloud after coarse registration is subjected to fine registration to a coordinate system of the laser point cloud, so that fine registration of the dense image point cloud and the laser point cloud after coarse registration is co