Achieving color uniformity across multi-projector displays

Abstract

Large area tiled displays are gaining popularity for use in collaborative immersive virtual environments and scientific visualization. While recent work has addressed the issues of geometric registration, rendering architectures, and human interfaces, there has been relatively little work on photometric calibration in general, and photometric non-uniformity in particular. For example, as a result of differences in the photometric characteristics of projectors, the color and intensity of a large area display varies from place to place. Further, the imagery typically appears brighter at the regions of overlap between adjacent projectors.In this paper we analyze and classify the causes of photometric non-uniformity in a tiled display. We then propose a methodology for determining corrections designed to achieve uniformity, that can correct for the photometric variations across a tiled projector display in real time using per channel color look-up-tables (LUT).

Color gamut matching for tiled display walls

“…In the first test case we use a uniform array of 4 DLP projectors, and in the second case we use a mixed array consisting of one DLP projector and one LCD projector. For these tests we implemented the FGCM algorithm in Matlab, and for comparison we implemented an ICB algorithm, such as that described in 5,9 . Section 4.1 details the measurement method and metrics we use to measure the accuracy of these algorithms and Section 4.2 gives experimental results.…”

“…Majumder et al proposed the use of Luminance Attenuation Map (LAM) to equalize the luminance output across the display wall 6 . Majumder et al 5 presented a generalized description of the problem and proposed a method to partially address the issue of color matching through an independent intensity matching on red, green and blue channels of all projectors. Stone 9 presents an algorithm for finding the standard gamut of LCD projectors and gives a characterization of the problems DLP projectors present in color balancing.…”

Life-sized projector-based dioramas

“…Another problem of merging images from multiple projectors is the lack of color equivalence between neighboring projectors [16]. Majumder et al use hardware color look-up tables to correct for the color mismatch between projectors.…”

Optimized color gamuts for tiled displays

“…This problem was previously considered by Stone [22], who described a non-automated procedure for finding a large common color gamut for tiled displays. Majumder et al [14] also studied color matching problems in tiled displays, however their paper addresses only the related problem of mapping a suitable device-independent gamut into individual projectors' color spaces, and does not discuss how to find such a gamut. We show how to formalize this challenge as a computational geometry optimization problem, and describe efficient algorithms for solving various formulations of this problem.…”