A point cloud and image automatic high-precision registration method based on mutual information

Abstract

The invention discloses a point cloud and image automatic high-precision registration method based on mutual information. The method comprises the steps of shooting a close-range optical image of a to-be-detected object; collecting ground laser scanning point cloud of the to-be-detected object, and generating an RGB color image and a reflection intensity image; calculating coarse registration parameters by using the close-range optical image and the point cloud RGB color image; extracting Harris operator feature points from the reflection intensity image by grids; a Forstner positioning operator is used for accurate positioning, rough registration parameters are used for calculating the initial positions of corresponding homonymous points of the feature points, the mutual information theory is used for searching for accurate matching point positions of the feature points in the close-range optical images in the initial positions, and accurate homonymous feature point pairs of the two images are obtained; calculating a fine registration parameter; and generating an accurate color point cloud model of the to-be-tested object. The method is not influenced by non-homologous data projection and radiation difference, and meets the requirement for reconstruction of a high-precision three-dimensional color texture model in the cultural relic protection industry.

Description

technical field [0001] The invention relates to the technical fields of photogrammetry and laser radar, in particular to a method for automatic high-precision registration of point clouds and images based on mutual information. Background technique [0002] With the development of my country's science and technology and economy, all sectors of society pay more and more attention to the digital protection of cultural relics, and have higher requirements for the protection, management and utilization of cultural relics, including 3D data display of cultural relics, research on cultural relics disease, cultural relics simulation model, Cultural relic derivatives, etc. The high-precision 3D color model reconstruction of cultural relics is the basis of digital protection of cultural relics. It is usually realized by the registration and texture mapping of ground laser scanning point clouds and close-range images. The registration of the two data is the key content of high-precisio...

AI Technical Summary

Problems solved by technology

The automatic registration of the two data has always been the focus of research by scholars at home and abroad. At present, the main methods for the automatic registration of ground laser and point cloud are: the integration of sensors, and many instrument companies have launched scanners with built-in cameras, which can directly scan out color points. cloud, but the texture resolution and positioning accuracy do not meet the requirements; for feature-based registration, most studies focus on extracting the homonym line features of point cloud and image for registration, this method is not suitable for irregular complex objects, and the homonym Automatic extraction of feature points Due to the non-homogeneous heterogeneity of the two types of data, it is difficult to obtain the correct point pairs with the same name based on the matching of image grayscale information, and the robustness is poor

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