Forensisk längdmätning i bilder

by Brolund, Per

This Master Thesis investigate forensic measurement from images, e g height estimation of humans in images concerning crime investigations. The problems are identi ed and some of today's existing height estimation methods are discussed. The method which best ful ll the set up requirements; fast processing, minimal system information, minimal calibration and precision, has been selected, adapted and evaluated. The method are based on nding vanishing points and vanishing line in the image and by one, in the scene, known reference height calculate the required height. The underlaying theory of the method is presented and the method is described in detail. Functions, algorithms and a user interface has been implemented in the calculation program MatLab. Tests has been carried out to validate the precision of the method and the dependency of the parameters. The method appears to give very good result under the right conditions but seems to be sensitive for variation on the vanishing line. The Master Thesis is a mandatory element in the education program Master of Computer Science and Engineering provided by Linköping University. The work has been carried out for National Laboratory of Forensic Science (SKL) in Linköping. Nyckelord