Pixel-wise Inter/intra-channel Color & Luminance Uniformity Corrections for Multi-channel Projection Displays

Interand intra-channel color and luminance are generally non-uniform in multi-channel projection display systems. Several methods have been proposed to correct for both interand intra-channel color and luminance variation in multi-channel systems in the past, with varying degrees of success. In this paper, a color and luminance correction method is proposed that alters the luminance and chromaticity of a projected image on an approximately pixel-wise basis by employing an imaging colorimeter. The final result is a pixel-wise gain mask, unique to each projector, which can be inserted into either the projection system or the image generator rendering pipeline to perform the required color calibration. This paper will describe the equipment, process, and algorithms required to perform such a correction using the Operational-Based Vision Assessment (OBVA) simulator as an example. Using this method, the 15-channel, 150-megapixel OBVA simulator display system is calibrated to uniform D65 and native white points, with uniform luminance, using luminance as the free parameter.