Research On 3D Footprint Scanning System Based On Structured Light Technology

With the development of science and technology,the importance of high-tech means in the detection of criminal cases by public security organs is increasingly increasing.Footprints play a crucial role as direct evidence in the investigation of criminal cases.The information contained in footprints can be used to infer the characteristics of suspects and help police officers determine the direction of the case.How to effectively extract,compare,and analyze on-site footprints is the key to footprint detection.At present,footprint detection has been relatively mature in terms of reasoning and analysis theory in China,but its degree of digitization and intelligence is relatively low.In view of the shortcomings of traditional footprint detection methods,this topic has developed a set of footprint 3D scanning and analysis system based on structured light technology,which makes up for the shortcomings of traditional 2D footprint detection technology and extracts footprint 3D data efficiently and nondestructive.Designed and developed algorithms such as preprocessing and feature parameter extraction to automatically analyze 3D footprint data,ultimately obtaining various physical features of the suspect.Compared to traditional footprint detection methods,this system has advantages such as automation,intelligence,and strong robustness.The main work of this thesis is as follows:1.A complex scene 3D measurement algorithm for footprint detection has been proposed.Achieved high-precision 3D measurement of footprints in overexposed,underexposed,and mixed exposure environments.Identify and extract unexposed stripe images for mixed exposure phenomena in complex scenes;Establish a stripe description equation for non equidistant stripes,propose a non equidistant phase extraction algorithm,and then complete three-dimensional measurement of footprints in complex scenes.2.Designed an intelligent footprint analysis algorithm based on 3D data.Based on point cloud data,algorithms such as point cloud filtering,plane removal,edge detection,and footprint feature point extraction have been developed,achieving automated and intelligent analysis of 3D footprint data.3.Developed a three-dimensional footprint scanning and analysis system based on structured light technology.Functions such as system calibration,phase extraction,three-dimensional reconstruction of footprints,feature extraction of footprints,and suspect feature inference are implemented.The footprint detection and analysis system developed in this thesis extracts three-dimensional data of footprints,which contains more information than traditional two-dimensional footprint images.The developed intelligent analysis algorithm can effectively extract the footprint features needed by suspects for reasoning,providing support for assisting police officers in detecting cases.