CLARITY-HDRTM
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High Dynamic Range (HDR) refers to a technology that enables high-contrast digital imaging and video. While DeepColor
and the xvYCC color space are intended to enhance the number of shades within a given black and white point, HDR enables pixels to assume values beyond the white point, thus allowing for extreme pixel contrast and digital dynamic exposure.
As opposed to HDR which requires 96-bits/pixel for full representation, LDR is the acronym for “Low Dynamic Range” digital images or video, i.e. the common 24-bits/pixel representation, where the maximum numeric value for luminance is also the white-point of the image. Other external references:
Standard lossy compression algorithms such as JPEG, DXTC, MPEG2, MPEG4 and similar, heavily introduce errors and artifacts into images and movies, but are essential in order to fit content into standard media such as CD-ROM, VCD, DVD, Blu-Ray Disc™ and HD-DVD™.
Said algorithms are not suited, alone, for DeepColor nor for HDR input data. The increased precision in source data causes JPEG, MPEG and the like, to introduce more noticeable errors, thus degrading the picture to undesirable and unpractical results. Other external references:
Presently, there only exist other two methods to encode HDR image data so that it can be compressed using popular
algorithms like JPEG, and just one other method to encode HDR video so that MPEG-like algorithms can be
applied to it.
CLARITY-HDRTM offers notable advantages over said existing methods while being simpler to implement, more consistent and much "lighter" in terms of computational power required for encoding/decoding. Specifically, CLARITY-HDRTM allows for:
Here we present a first comparison between Microsoft's HD Photo and CLARITY-HDR™. The test image is the well known "Grace Cathedral" light probe by Paul Debevec.
The latest available version of the HD Photo plugin for Photoshop® CS2/CS3 has been employed in order to compress the source .hdr (Radiance) file. In the following animation it is possible to notice the higher details preserved by the CLARITY-HDR™ system, while the file size is even smaller than its HD Photo counterpart version. Click the picture below and see the difference: 
CLARITY-HDR™ defines a whole new level of quality in High Dynamic Range image and video compression while keeping backward-compatibility with existing technologies and file formats and maintaining the usual compression ratios, thus making High Dynamic Range support completely transparent to the end-user. A Photoshop CS2/CS3 plugin based on CLARITY-HDR™ will be available soon from Trellis Management, free of charge for non-commercial uses. Other external resources:
CLARITY-HDRTM
is currently in patent pending status.
If you want to learn more about it, please visit the dedicated Download Page, or contact us and we will provide you with detailed information and any available software implementation.
DISCLAIMER | Trellis Management Co. Ltd. is not affiliated in any way with companies, institutions and/or individuals cited herein, unless otherwise specifically stated.
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