Comparative Analysis of Structured Light Scanning and Photogrammetry for 3D Digitization of Costume Collections: Towards a Model for Best Practices

Abstract

The purpose of this mixed methods study is to develop best practices in workflows and equipment specifications for 3D digitization of costume. Recent advancements in 3D technologies are providing new means of preserving and disseminating cultural and historical collections. However, the comparison of structured light scanning and photogrammetry (structure from motion) for 3D imaging costume has received little attention. This research proposes a model for best practices in 3D imaging costume to advance digitization practices for cultural institutions. A review of the literature discussed previous developments in digitization of costume collections. Research activities were completed in two phases using a mixed methods design. First, structured light scanning and photogrammetry were compared to evaluate the advantages and limitations of both technologies for 3D digitization of costume. One Swedish folk costume and one contemporary blouse were selected as appropriate candidates to evaluate the performance of these technologies. Second, three institutions with costume collections participated in interviews to discuss the feasibility of 3D digitization of costume. Data were analyzed according to qualitative descriptions of 3D model texture, color, and geometry quality. In addition, 3D models were analyzed using descriptive statistics to report metadata and color accuracy. Qualitative interviews were coded using thematic content analysis. The results of the comparative 3D models revealed both technologies had strengths and weakness in capturing an accurate representation of the real object. Structured light scanning delivered high precision of geometry, but had lower resolution of texture and color. By comparison, photogrammetry provided photorealistic texture and color, but lower accuracy of geometry. Both techniques encountered distortions due to challenging materials, such as reflective and dark surfaces. Moreover, neither technology had a greater accuracy capturing the true color of the real object. The results of the qualitative interviews revealed the state of the art in collections digitization may not be positioned for 3D practices just yet. Smaller institutions continue to face significant barriers to 2D digitization, such as funding and access to equipment. While there is interest in 3D digitization, further work needs to be done to establish 3D digitization standards and imaging guidelines. The findings of this study contribute to advancing best practices in 3D digitization of costume collections. The recommendations discuss the feasibility according to accessibility, usability, and performance of 3D scanning and photogrammetry for digital preservation of costume. By expanding the knowledge of 3D imaging techniques for costume collections, best practices in 3D digitization will support institutions in advancing preservation and accessibility for research, teaching, and public programming.