Illustrating motion through DLP photography

Abstract

Strobe-light photography creates beautiful high-frequency effects by capturing multiple object copies. Single-chip DLP projectors produce a similar effect, with two important distinctions. Firstly, strobing occurs at different frequencies: at 10000 Hz, due to the DMD chip, and at 120 Hz, due to the colorwheel. Secondly, DLP illumination lacks the perception of `on-off' flashing that characterizes a strobe-light, since these frequencies are beyond human perception. While higher spatial frequencies are preserved in a motion-blurred DLP photograph, deblurring is still difficult, especially for articulated and deformable objects, since the deconvolution kernel can be different at each pixel. Instead we process DLP photographs to create new images that either summarize a dynamic scene or illustrate its motion. We conclude by discussing the frequencies present in DLP photographs, comparing them to images taken under skylight and fluorescent light.