Optimized GPU-based post-processing for stereoscopic multi-projector display systems

Abstract

To drive multi-projector display systems, the image content has to be post-processed to apply geometrical and photometrical correction algorithms. Since the optical path is shared for both views of a stereoscopic projector, we propose to eliminate redundant calculations by processing both views at once. We show that by exploiting the color similarities of stereoscopic image pairs, the cache efficiency of LUT-based color correction methods can be improved. Stereoscopic content is often transmitted in different formats where a single frame represents both views in a spatially multiplexed pattern, and display devices typically support only a subset of these formats, so that the need for conversion arises. We propose an algorithm to directly incorporate such format conversions into the post-processing and show that our combined approach can achieve significant performance improvements compared to the naive multi-pass implementation. The reduced overhead of the post-processing step increases the number of projectors which can be driven by a single GPU, which enables building larger or higher resolution displays at lower costs. The flexibility gained by the ability to process different input formats also greatly enhances the usability of powerwalls by allowing to implement the post-processing at different levels and working with unmodified software applications.