Documentation of the most important petroglyphs by structured light scanning and analysis of the most damaged petroglyphs by vPTM and vRTI methods

Abstract

Digital image processing techniques have been developing since the beginning of this century, resulting in more and more uses for them. For documenting and analysing rock art heritage, two groups of techniques deserve special attention. Both of them help to identify items that are not visible to the naked eye. The first group are applications based on the transformation of a single digital image. Among them, ImageJ [1] deserves special attention. This is an open-source Java application commonly used by many rock art researchers. It allows simple geometric transformations to be made (for example, cropping, scaling, resizing and rotating, flipping vertically or horizontally) as well as much more advanced image enhancement (for example, smoothing, sharpening, edge detection, median filtering, thresholding on grayscale

Reflectance Transformation Imaging for the Recording of Incised Graffiti

“…Other techniques, including Virtual Polynomial Texture Mapping Virtual PTM (VPTM; see, for example, Kosćiuk et al 2020), could be used to overcome some of the limitations of the close proximity of the tunnel in that the light source is applied after a 3D photogrammetric model is created. However, a drawback would be that the 3D model would need to be created and checked in the field to make sure that all details were recorded sufficiently, and very faint incisions, as is often the case in graffiti, may not always be recorded.…”