Photogrammetry

ELCOVISION 10 Forensic

Mit ELCOVISION 10 erzeugte Punktwolke eines simulierter Tatort in einer Tiefgarage

The ELCOVISION 10 product line follows a very simple philosophy: The programs should be as simple as possible to use while being as universal as possible. From time to time, however, there are special applications such as blood spatter analysis or perpetrator size determination..

Blood Spatter Analysis

The ELCOVISION 10 Forensic Plugin allows the easy and accurate measurement of blood spatters and their origin. A simple example will show the workflow for blood spatter analysis..

First, the crime scene is photographed with a high-quality camera and these images are automatically oriented with ELCOVISION 10. The fully automatic orientation of ELCOVISION 10 is particularly suitable for this purpose, as optimal images for photogrammetric evaluation can rarely be taken indoors: ELCOVISION 10 can also automatically orient images with a large convergence angle and, if required, calculate a very good point cloud from the scene of the crime.

The most important ELCOVISION 10 function for blood spatter analysis is the automatic rectification of surfaces in the CAD drawing. This automatically transfers every blood spatter from the crime scene to the correct 3D position in the drawing, eliminating the need for tedious measurement of individual tracks. Even drops of blood on curved and slanted surfaces can be used.

The ELCOVISION 10 Forensic Plugin has several tools to describe a blood spatter exactly with an ellipse. The circumscribing ellipse is automatically exactly at the right 3D position in the room. 

If enough blood spatters have been circumscribed with ellipses, the Trajectory Calculation tool is used. This tool determines which trajectories belong to each other and calculates the 3D origin of these blood spatters and their accuracy range. This result is immediately displayed as a sphere in the drawing so that the result can immediately be checked for plausibility. The sphere describes the volume of space from which the blood spatter originates.

 


Offender Height Determination

With ELCOVISION 10 the surveillance camera will be calibrated automatically from the pictures taken by a high quality camera and a point cloud will be generated.

ELCOVISION 10 is able to calibrate even very strong distorting images of surveillance cameras. Even glass panes in front of the surveillance camera lenses are no problem for the automatic camera calibration of ELCOVISON 10.

This generated point cloud is then imported into a supported CAD, preferably BricsCAD V20 or newer, using the ELCOVISION 10 CAD plugin.

With the Forensic Module a function is available to place a humaniod in the drawing and bend it at all joints, enlarge or shrink it and position it until it is displayed exactly above the perpetrator in the surveillance images. If this is the case, depending on the image quality of the surveillance camera, the offender's size is typically determined to within 1-2 cm.

This whole process takes only a few minutes per surveillance image for a trained operator. A built-in statistical evaluation of several recorded offender sizes eliminates outliers and allows an additional increase in accuracy.


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