Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)

Computer-based image analysis of granite rocks in the Bedřichov tunnel – classification of an alteration degree


Veronika Kopáčková, Josef Klomínský

Geoscience Research Reports 45, 2012 (GRR for 2011), pages 177–180
Map sheets: Liberec (03-14)

Full text (PDF, 1.98 MB)



In our study we tested feasibility to detect and classify minerals indicating alteration processes in granite rocks (the Jizera-type granite) using high-resolution photographs taken sequentially in the Bedřichov water supply tunnel. The altered zones in granite could be visually depicted as the newly created secondary minerals, which changed colours of the original rock. We pre-processed the whole sequence of individual photographs and created seamless xy-oriented photo-mosaics. Then the ISODATA algorithm was employed to automatically depict altered zones in the digital image.