RTI compression for mobile devices

Currently, Reflectance Transformation Imaging (RTI) technology is restricted to desktop and high performance computing devices. In recent years, mobile devices and tablets have become ubiquitous due to their increased performance. However, the size of RTI files (≈100 MB) limits the range of portable devices capable of displaying RTI files. In this paper, we explore different compression techniques, and develop an RTI viewer prototype for both Android and iOS devices. Experiments with JPEG, JPEG2000, lossless compression show the resulting error for compression ratios of 30:1 is comparable to the error of traditional two-dimensional images. For higher compression rates, we present a novel αβ-JPEG algorithm which compresses color and reflectance information individually.