AIC's 47th Annual Meeting

Digital Image Correlation (DIC) is a visual analysis tool which allows for mapping of the strain inflicted by stress upon a surface. Simply put, it records the pattern of movement required for a “before stress” image to become an “after stress” image. This pattern can be read as a coloured overlay over the original image, where levels of strain are noted by a colour gradient. In recent years this tool has been used to record strain upon hanging textile materials, particularly tapestries with the United Kingdom. This poster highlights the first stage of a project to further investigate DIC’s potential to map strain across conservation stitching. It follows on from research done by the author at the Centre for Textile Conservation, University of Glasgow, which in turn followed on from several pieces of work, notably that of the Tapestry Monitoring Research Project, based out of the University of Southampton, 2007 – 2010. The author’s personal interest in encouraging wider discussion of stitched treatments within textile conservation also prompted this poster presentation. The hardware and software required to produce DIC data can be expensive. In order to make future research more accessible, this stage of the project investigated the potential of various open-source DIC processing tools. It also utilized easily available equipment such as departmental digital cameras and free photo editing tools. Photographs, before a stress was applied and after a stress was applied, were taken of several identical fabric samples; all artificially damaged and then “conserved” with support fabric and lines of laid-thread couching. These sets of photographs were processed through a series of open source DIC software to compare the outcomes of each program. Software was considered from various angles including accuracy of image processing, speed of image processing and ease of use for staff without engineering backgrounds. The photographs were also processed through a commercially available software for comparison. The chosen camera and software combination will be used in the second stage of the project, which starts in 2019. This stage will focus specifically on analyzing how the spread of laid-thread couching away from areas of damage impacts the spread of strain on a hanging textile.