Reconstitution of facade digital image by means of calibration of lens distortion

Abstract

International entities have been making an effort for the divulgation of techniques
that facilitate the study and conservation of historical building and works of art.
Photogrammetry is crucial in this context since it allows the metric morphologic
reconstitution of the examined object. At present, digital amateur cameras have
been used in the architectural photogrammetry, but the attainment of geometric precision is only reached following the relatively complex photogrammetric
procedures, so such calibration, control point surveying, adjustment of the
phototriangulation and compilation by using special hardware and software.
However, for some types of works so such cadastre for future restoration of
buildings with facades that have a predominant vertical plan, it is possible to carry
out the survey with simpler methods. This work shows a system of low cost for
images acquisition, that is formed by an unexpensive digital camera, direct
measurements with tapes and processing of the images by programs that correct
lens distortion and perform rectification. The rectified images can be used to
compose an archive of low cost and they can be restituted for attainment of the
measures in programs type CAD. The method was applied in the Church of Nossa
Senhora do Rosário in Recife, PE.