Connecting Systems To Displays: HDR Defined

January 3, 2007

This blog post references my cover story 'Connecting Systems To Displays: What We Got Here Is A Failure To Communicate' in EDN's January 4, 2007 edition.

My article, as one of the justifications for HDMI 1.3's higher bandwidth, points out its consequent 'deep color' support. What I'm referring to here is support for images with greater than 24-bit color depth (said another way, support for images that preserve more than 8 bits of per-color data). Since most common video formats, delivered both from optical discs (ie CD, DVD, HD DVD and Blu-ray) and from wire- and wireless-connected sources (OTA, satellite, cable, IPTV and Internet, etc), support 24-bit maximum color depths, 'deep color' images are most likely to first appear sourced from my article's 'three Cs'; cameras, computers and game consoles.

'Deep color' is also known as HDR (High Dynamic Range), both for image capture and for 3-D rendering. Advanced image editing programs such as Adobe Photoshop CS2 offer limited HDR support (the upcoming Photoshop CS3 promises to deliver expanded HDR provisions), a capability that's particularly meaningful if the photographer captured the original image in a RAW format (it can also be simulated by capturing several images of the same scene at various exposure settings-under, correct, and over-and subsequently blending them together). This article (PDF) from the November/December 2005 issue of IEEE Computer Graphics and Applications proposes a scheme for appending HDR support to the JPEG 2000 format.

With respect to 3-D HDR image rendering, Nvidia has been particularly aggressive in promoting the technique. See this Google search of the Nvidia Developer site for more information. Developers Crytek (with Far Cry) and Valve (with Half-Life 2) are among the early implementation innovators in the HDR arena. And you can probably image how excited display manufacturer BrightSide Technologies is about the HDR trend.

For more information on HDR, please reference the following chronologically-ordered (by publication date) reading list, culled from RSS feeds I've archived since attending the 2005 SID ADEAC conference in anticipation of this article's eventual publication. I can also highly recommend a book called 'High Dynamic Range Imaging', published by Morgan Kaufmann (ISBN-10: 0125852630, ISBN-13: 978-0125852630).

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Posted by Brian Dipert on January 3, 2007 | Comments (0)

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