Comparative Study On Visible Multispectral Imaging And Near-infrared Hyperspectral Imaging To Develop Potential Bloodstains

The Bloodstain is the most common and one of the most important physical evidence on the murder scene.However,due to the increasingly complex nature of the case,there are certain limitations in the existing chemical and optical methods of developing bloodstains,especially the potential bloodstains on the object of fabrics and traces of suspected bloodstains.The spectral imaging technology can obtain the spectral characteristic curve of each substance while obtaining the spectral image set of the target substance.Therefore,spectral imaging techniques can not only visualize potential bloodstain through spectral images,but also further analyze,visualizes and distinguishes bloodstains and other traces based on acquired spectral characteristic curves,and rapidly develops potential bloodstains for crime scene investigations,and provides data reference.In order to study the specific methods of spectral imaging technology for the development of enhanced potential bloodstains,we selected the Visible Multispectral Imaging System(Effective spectral band 450nm-950nm)and Near-infrared Hyperspectral Imaging System(Effective spectral band 900nm-1700nm),and selected a large red,wine red,black,blue,green,brown,a total of six colors,and selected cotton,polyester,nylon,wool,canvas five kinds of textile fabrics,as well as a high incidence of crime scene blue denim and black,red gold Velvet is the object of fabrics,with different concentrations of blood traces left on it,8 different brands of soy sauce traces,5 different brand colors of lipstick traces,3 ink traces of the same brand with different colors and 6 different brand colors stamp pad ink traces were separately subjected to spectral imaging to show experiments.The Visible Multispectral Imaging System and the Near-infrared Hyperspectral Imaging System collect data of spectral images and spectral characteristic curves of different material traces left on different fabrics respectively,and perform comparative analysis of the visual effects to obtain the potential of different concentrations on fabrics.The best method for developing potential bloodstains and distinguishing potential bloodstains from fabrics on the traces of soy sauce,lipstick,ink,and stamp pad ink,provide a reference for further perfecting and applying spectral imaging technology to achieve rapid on-site visualization of potential blood stains on fabrics.The research results show that spectral imaging technology can effectively and nondestructively develop potential bloodstains on fabrics at the crime scene,and can effectively distinguish lipsticks,soy sauces,and stamp pad ink traces that show high similarity to blood traces.The Visible Multispectral Imaging System and the Near-infrared Hyperspectral Imaging System have different effects on different material traces,textile colors,and fiber types.In this paper,through experiments,these differences are analyzed and compared with the data obtainedfrom the spectral information,and the feasibility methods applicable to crime scenes to develop potential bloodstains on fabrics are summarized and explored.