Improving the Retinex algorithm for rendering wide dynamic range photographs

Robert Sobol

doi:10.1117/1.1636762

1 January 2004 Improving the Retinex algorithm for rendering wide dynamic range photographs

Robert Sobol

Journal of Electronic Imaging, Vol. 13, Issue 1, (January 2004). https://doi.org/10.1117/1.1636762

Digital photography systems often render an image from a scene-referred description with very wide dynamic range to an output-referred description of much lesser dynamic range. Global tone maps are often used for this purpose, but can fail when called on to perform a large amount of range compression. A modified luminance formulation of the Retinex ratio-reset-product-average algorithm produces a smoothly changing contrast mask of great benefit, but it too can fail where high-contrast edges are encountered. A small but critical modification to the Retinex equation—the introduction of a ratio modification operator—changes the nature of the generated contrast mask, so that it is simultaneously smooth in regions of small contrast ratios, but extremely sharp at high-contrast edges. A mask produced in this way compresses large and undesirable contrast ratios while preserving, or optionally enhancing, small ratios critical to the sensation of image contrast. Processed images may appear to have a greater contrast despite having a shorter global contrast range. Adjusting the new operator prior to processing gives control over the degree of compression at high-contrast edges. Changing the operator during processing gives control over spatial frequency response.

©(2004) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Robert Sobol "Improving the Retinex algorithm for rendering wide dynamic range photographs," Journal of Electronic Imaging 13(1), (1 January 2004). https://doi.org/10.1117/1.1636762

Published: 1 January 2004

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available