9th Experimental Archaeology Conference abstract – Surette
Capturing fugitive dyes through re-creation and algorithms: a case study from the north coast of Peru
The University of Western Ontario
Despite nearly a hundred years of textile research in Peru, experimental approaches and novel applications of technology are rarely applied to material excavated from the region. For this project, I tested the effectiveness of Dstretch, a decorrelation stretch algorithm plug-in for ImageJ developed by researcher Jon Harman to study rock art. I used this program to enhance the faded dyes of a series of textiles recovered from Huaca Santa Clara, an Early
Intermediate Period (200 B.C.-A.D. 800) site located in the Virú Valley on the north coast of Peru. Seven examples of plangi or tie-dyed textiles, light blue cloth with faint red or light brown rings or diamonds, were selected, revealing ring motifs largely hidden in photographic form and barely visible to the naked eye. In other cases, the algorithm revealed dyed patterns invisible in photographs and enhanced the colour-leached outlines of tapestry motifs. With the relative ubiquity of high quality photographs, this technique adds a new dimension to research where circumstances prevent in-person analysis. The second and ongoing aspect of this experiment involves the re-creation of the ring motif, using material and dye available to artisans during the period in question, in order to test the
effectiveness of the algorithm on other common colours. These samples will also be subjected to a bleaching process to mimic the changes undergone by archaeological textiles and will also be photographed under less-than ideal conditions to test the utility of the algorithm where low quality photographs are the only option available. The overall goal is to determine the applicability of this particular technique (algorithm) for textiles where its usefulness has been met in the study of rock art.
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Harman, Jon, 2008 Using Decorrelation Stretch to Enhance Rock Art Images. Retrieved from http://www.dstretch.com/AlgorithmDescription.html.
Rehl, Jane W., 2002 Weaving Metaphors, Weaving Cosmos: Struture, Creativity and Meaning in Discontinuous Warp and Weft Textiles of Ancient Peru, 300 B.C.E.-1540 C.E. PhD Dissertation: Emory University.
Webster, Laurie, Keley A. Hays-Gilpin and Polly Schaafsma, 2006 A New Look at Tie-Dye and the Dot-in-a-Square Motif in the Prehispanic Southwest. Kiva 71: 317-348.