Close range photogrammetry

Imagery can be extremely valuable material for heritage documentation, especially for conservation planning and evidencing. Unfortunately, individual picture covers relatively small area and contains lens distortion and misalignments caused by center projection of 3D object to 2D image plane. Using large sets of overlapping digital images, carefully acquired with calibrated cameras DEPHOS Group professionals create detailed 3D model of the object and apply mathematical routines to convert pictures into distortion and misalignment free same scale orthoimages. Those are then seamlessly stitched into one consistent image called orthophoto. With use of precisely surveyed control points orthophotos are georeferenced to have real object coordinates. The terrestrial orthophotos that DEPHOS Group delivers to architects and heritage preservation agencies provide true, digital representations of objects like stone or brick walls and wall paintings in virtually unlimited resolution. With pixel size down to even 0.1 mm, orthophotos provide measurable detail for architects and conservators undertaking renovations to use in their design work. If required by project demands, especially for wall paintings, orthophotos can be color balanced using professional grade color calibration techniques.