History

What is HDRI?

a set of techniques that allow a greater dynamic range of luminances between the lightest and darkest areas of an image.

· This wider dynamic range allows HDR images to represent more accurately the wide range of intensity levels found in real scenes ranging from direct sunlight to faint starlight.

What is it used for?

computer renderings and photography

HISTORY

1850

The idea of using several exposures to fix a too-extreme range of luminance was pioneered as early as the 1850s by Gustave Le Gray

1930

High dynamic range imaging was originally developed in the 1930s and 1940s by Charles Wyckoff. Wyckoff's detailed pictures of nuclear explosions appeared on the cover of Life magazine in the mid 1940s. Wyckoff implemented local neighborhood tone remapping to combine differently exposed film layers into one single image of greater dynamic range.

1980

First practical application of HDRI was by the movie industry in late 1980s and, in 1985, Gregory Ward created the Radiance RGBE image file format which was the first (and still the most commonly used) HDR imaging file format.

1993

Global HDR was first introduced by Steve Mann: different approach, based on making a high-dynamic range luminance or light map using only global image operations (across the entire image), and then tone mapping this result.

1997

Global-HDR technique of combining several differently exposed images to produce a single HDR image was presented to the computer graphics community by Paul Debevec

2005

Photoshop CS2 introduced the Merge to HDR function