A photogrammetric range imaging technique, namely Structure from motion (SfM), is used to create a detailed 3D model for each mummy under study from a two-dimensional image-set. The resulting highly detailed and accurate 3D renderings of the mummies improve the legibility of the complex interweaving of the wrapping weaves, which would have been difficult to discern through traditional visual inspection, significantly enhancing the study’s capacity to interpret and document the artifacts’ original decorative module.
The mummies are placed horizontally on a turntable inside a light box, which help to avoid light pollution and reflections produced by black matters applied on the mummies. Another solution adopted to reduce light noise is to always place the camera on a tripod and delay the shot by a few seconds, using a remote control, to avoid vibrations. This allows the use of low ISO values, even in low-illuminated museum rooms.
The acquisition geometry is circular with the camera remaining stationary and the turntable rotated at 15-degree intervals, to avoid direct contact and any stressful handling of the artefacts. Images are taken from 3 different levels per 3 sides of each artifact, to guarantee an image overlap of more than 85% and the acquisition of every feature of the mummies.
The reconstruction of the photogrammetric models is performed through 3D Flow Zephyr. This software automatically recognized the targets on the turntable, which are essential for generating robust and reliable photogrammetric models.
This rigorous photogrammetric approach, resulted in highly detailed and accurate 3D models of the mummies, enables the extraction of their intricate wrapping features, and the subsequent creation of precise drawings, which serve as geometric references for the next steps of the workflow.