Principle of the photogrammetric evaluation is the parallax measurement (stereoscopic image arrangement). Menci from Italy provides an easy to handle software named ZGlif. The process is done in three steps.
- Loading images and camera definition
- Relative and absolute image orientation
- Parallaxe measurement in an CAD like environment
Orientation computes the photo positions and the co-ordinates of orientation points ( automatically found by the system). Control points are connected with the corresponding position on the images and the software provides the adjustment of the calibration parameters. Quality of the orientation can be read from the residuals given for the corresponding points.
Two half screens or anaglyph display the left and right photo. Measurement is made by using points, lines, polylines and rectangles from three points inside the CAD window. Layers also are considered to make easier understanding different elements of the model. The results are exported into DXF format in order to generate a draft of the 3D model.
Screenshot from ZGlif measurements
Anaglyph image from a steropiar
© University of Applied Sciences Bielefeld 2011