Photographic Tone Reproduction for Digital Images

Erik Reinhard, Mike Stark, Peter Shirley and Jim Ferwerda

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Evaluates methods for mappng photographic tones efficiently to digital images

The range of light we experience in the real world is vast, spanning approximately ten orders of absolute range from star-lit scenes to sun-lit snow, and over four orders of dynamic range from shadows to highlights in a single scene. However, the range of light we can reproduce on our print and screen display devices spans at best about two orders of absolute dynamic range. This discrepancy leads to the tone reproduction problem: how should we map
measured/simulated scene luminances to display luminances and produce a satisfactory image?

Overcoming Gamut and Dynamic Range Limitations in Digital Images

Gregory Ward Larson

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Covers several methods for encoding images in a colour-space-independent format.

We have presented a new method for encoding high dynamic range digital images using log luminance and
uv chromaticity to capture the entire visible range of color and brightness. The proposed format requires little
additional storage per pixel, while providing significant benefits to suppliers, caretakers and consumers of digital imagery.

A Real Time High Dynamic Range Light Probe

Jamie Waese and Paul Debevec
SIGGRAPH 2001 Technical Sketch

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Discusses methods for the creation of HDR images for use in image-based lighting applications, using muliple exposures.

One solution for creating a real time high dynamic range light probe is to develop a system in which multiple exposures of the same image can be captured within a single video frame. We did this by modifying a five point Multi-Image Filter (a faceted lens that is commonly used to create photographic kaleidoscope effects), and applying successively increasing values of neutral density gel to four of the five facets of the filter (3⅓, 6⅔, 10 and 13⅓ stops).

The “Buntes Fernsehen project” is a local TV channel run by and for the people of Engerwitzdorf. They shoot and edit their own programmes, upload it onto a central server on the net, where other residents can then download and watch it. Content currently includes current events, sports and politics.
This will undoubtedly serve as a model for other like-minded networks.

read the full article (BBC news)

The FCC has been told by a judge in an appeals court that it “crossed the line” by trying to enforce the inclusion of a system to recognise the “broadcast flag” in transmissions, in all devices capable of receiving them. This was due to come into effect on the 1st July. The idea is to prevent piracy, but would undoubtedly add to the complexity of devices (and price), and the board ruled that this type of restriction was “not what the FCC is in the business of”.

read the full article (BBC news)