A Practical Framework to Achieve Perceptually Seamless Multi-projector Displays

ADITI MAJUMDER: A Practical Framework to Achieve Perceptually Seamless Multi-Projector Displays (Under the direction of Prof. Greg Welch and Prof. Rick Stevens) Arguably the most vexing problem remaining for planar multi-projector displays is that of color seamlessness between and within projectors. While researchers have explored approaches that strive for strict color uniformity, this goal typically results in severely compressed dynamic range and generally poor image quality. In this dissertation, I introduce the emineoptic function that models the color variations in multi-projector displays. I also introduce a general goal of color seamlessness that seeks to balance perceptual uniformity and display quality. These two provide a comprehensive generalized framework to study and solve for color variation in multi-projector displays. For current displays, usually built with same model projectors, the variation in chrominance (hue) is significantly less than in luminance (brightness). Further, humans are at least an order of magnitude more sensitive to variations in luminance than in chrominance. So, using this framework of the emineoptic function I develop a new approach to solve the restricted problem of luminance variation across multi projector displays. My approach reconstructs the emineoptic function efficiently and modifies it based on a perception-driven goal for luminance seamlessness. Finally I use the graphics hardware to reproject the modified function at interactive rates by manipulating only the projector inputs. This method has been successfully demonstrated on three different displays made of 5 × 3 array of fifteen projectors, 3 × 2 array of six projectors and 2 × 2 array of four projectors at the Argonne National Laboratory. My approach is efficient, accurate, automatic and scalable – requiring only a digital camera and a photometer. To the best of my knowledge, this is the first approach and system that addresses the luminance problem in such a comprehensive fashion and generates truly seamless displays with high dynamic range.