New Trends in Digital Photogrammetry Teaching and Diffusion: the Z-glif Software

Many experiences have been done in the past in order to promote a wide diffusion of the photogrammetry both in teaching and professional works. Only the digital evolution allowed a real step forward in this direction. In the last years prof. Jachimski and prof. Grussenmeyer offer interesting and low-cost software solutions which help a lot the diffusion of the photogrammetric approach as a standard tool for architectural and archaeological applications. The paper presents a new easy-to-use but rigorous photogrammetric software named Z-Glif, produced by Menci Software, a private Italian software house which collaborates with Politecnico di Torino in order to produce new solutions in digital photogrammetry. Z-Glif allows a single model orientation and plotting. Both aerial and terrestrial, metric and non metric digital images can be used. Exterior orientation can be performed by using: the traditional two-steps approach (relative and absolute); the rigorous bundle adjustment solution; a simple method based on the relative orientation of a stereo-pair and the subsequent scaling by using just a known distance on the object to be surveyed (so absolutely oriented in a local 3D reference system). Considering that an automatic relative orientation can be computed by the software, Z-Glif is open also to unskilled users: the 3 x 3 rules for a correct stereo-pair acquisition and a basic use of the software is the only skill required to manage a complete and rigorous photogrammetric survey in a local reference system. The fit of the local system into the survey reference system can be performed directly inside a CAD environment. Also non metric images can be managed: a DLT approach is implemented in order to calibrate and orient a non metric stereo-pair: this procedure allows the management of old and film based images which are often the only source of historical metric data. The bundle solution allows the calibration of modern digital cameras by using a self calibration approach. Thanks to the digital approach, many automatic procedures have been implemented in order to simplify the management of a photogrammetric process by not skilled users. Semi automatic interior and relative orientation allow the user to speed up the preliminary phases of the photogrammetric process. The needed hardware is a simple PC without any particular device for the stereoscopic view: the stereoscopy is guaranteed by means of the color anaglyphic method. License policy provided are of three types: installation on a single workstation; installation on Internet and local server. Z-Glif collects the most important results and experiences acquired in the field of digital photogrammetry and in the architecture and archaeological applications of the photogrammetric technique thanks to the experiences and studies promoted inside CIPA in the last