Reducing Cinema Projectors Power Consumption using Global Dimming and Image Statistics

Digital cinema projectors illuminate giant screens, offering audiences the best immersive and social experience. Thanks to design improvements and full RGB laser light sources, recently released cinema projectors consume much less power and have a lower cost of ownership than previous generation systems. However, ongoing rise in energy costs still challenges the sustainability of commercial theaters. — To improve the power efficiency of displays, global dimming features are now being implemented in many consumer TVs and projectors. Global dimming of a display's light source not only leads to power savings but also improves the black level in scenes with limited bright features. Depending on the implementation, Global Dimming can either faithfully reproduce any content or trade accuracy for increased power savings. — In this article, we simulate the expected power savings of Global Dimming in cinema under various scenarios. Results show that limited power savings is to be expected when the input content is faithfully reproduced. Enabling the rendering of a limited number of pixels (using a percentile) greatly increases the power savings at the risk of creating visual artifacts. Combining limited rendering with refreshing dimming only at shot intersection seems to be the most promising approach, as it enables significant power savings while maintaining artifact-free rendering. Despite these promising results, implementing such an approach faces several workflow and distribution hurdles that need to be solved. Combining global dimming and lightsteering technology, where light can be used much more efficiently, could lead the way to significant power savings for exhibitors.

Published

2023-10

Content type

Original Research

Keywords

Power consumption, Digital Cinema, Global Dimming

DOI

10.5594/M002025

ISBN

978-1-61482-964-5