ImageMagick: High Dynamic-Range Images
Author: ImageMagick Studio LLC
Description: ImageMagick® is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (about 100) including GIF, JPEG, JPEG-2000, PNG, PDF, PhotoCD, TIFF, and DPX. Use ImageMagick to translate, flip, mirror, rotate, scale, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves. ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you can freely use, copy, modify, and distribute. Its license is compatible with the GPL. It runs on all major operating systems. The functionality of ImageMagick is typically utilized from the command line or you can use the features from programs written in your favorite programming language. Choose from these interfaces: MagickCore (C), MagickWand (C), ChMagick (Ch), Magick++ (C++), JMagick (Java), L-Magick (Lisp), PascalMagick (Pascal), PerlMagick (Perl), MagickWand for PHP (P [cell cut: 1167 characters, first 1000 kept]
Keywords: high, dynamic-range, images, ImageMagick, ImageMagic, MagickCore, MagickWand, PerlMagick, Magick++, RMagick, PythonMagick, JMagick, TclMagick, Image, Magick, Magic, Wand

## Introduction to High Dynamic-Range Images High dynamic-range imaging (HDRI) permits a far greater dynamic range of exposures (i.e. a large difference between light and dark areas) than standard digital imaging techniques. HDRI accurately represents the wide range of intensity levels found in real scenes ranging from the brightest direct sunlight to the deepest darkest shadows. ## Enabling HDRI in ImageMagick By default image pixels in ImageMagick are stored as unsigned values that range from 0 to the quantum depth which is typically 16-bits (Q16). With HDRI enabled, the pixels are stored in a floating-point representation and can include negative values as well as values that exceed the quantum depth. A majority of digital image formats do not support HDRI so any pixels outside the quantum range are clamped before they are stored. The mostly promising HDR image format is EXR. You will need the OpenEXR delegate library to read or write this format. Other HDR formats include TIFF and ImageMagick's own native format, MIFF. To enable the HDRI version of ImageMagick, use this Unix/Linux command:
      ./configure --enable-hdri
Under Windows, set the UseHDRI definition in the magick-config.h file and build. To verify HDRI is properly configured, look for "HDRI" in the version string:
      -> identify -version
      Version: ImageMagick 6.3.4 11/01/07 Q16 HDRI http://www.imagemagick.org

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