Modeling and Visualization of Three Dimensional Objects Using Low-Cost Terrestrial Photogrammetry

摘要

Several valuable heritage structures worldwide are in danger due to natural causes or human interferences. Therefore, a low-cost modeling technique is extremely important and widely needed for the preservation of heritage especially in poorer countries. This study evaluates the precision and accuracy of terrestrial photogrammetry via low-cost digital cameras to construct a 3-D model of an object. To obtain the goal, a building facade is imaged by employing two low-cost digital cameras, namely Canon and Pentax. The accuracy of the photogrammetric point clouds that are generated via the method is compared with a few natural control points collected via a laser total station. Cloud-to-cloud distance is computed for different 3-D models to investigate different variables such as camera type and control points. The results of the practical field experiment indicate that the mean differences between obtained 3-D models and reference points are in the range of 2.3-4.1 cm without using any control points. Using a few of the control points, the differences are improved such that they are between 1.4 and 1.6 cm. The comparisons indicate that the largest variances between the laser total station and photogrammetric outcomes occurred when the Pentax camera was used.