HDRMerge combines two or more raw images into a single raw with an extended dynamic range. It can import any raw image supported by LibRaw, and outputs a DNG 1.4 image with floating point data. The output raw is built from the less noisy pixels of the input, so that shadows maintain as much detail as possible. This tool also offers a GUI to remove ‘ghosts’ from the resulting image. Discover more about HDRMerge


HDRMerge is currently supported in Linux and Windows, with the Mac version on its way. You can find the archives for the latest release in the GitHub repository. Please, feel free to file bugs/feature requests using GitHub’s issues system.

Getting started

You may want to read the manual, or jump directly to the command line help with hdrmerge --help.

Feature List







v0.3: The first public version of HDRMerge


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HDRMerge is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

HDRMerge is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.


HDRMerge is what it is thanks to all the people that have contributed ideas, critics and samples to improve it. In particular, thanks to the team of RawTherapee. Also, HDRMerge implements or is based on the techniques described in the following works:

  1. Ward, G. (2003). Fast, robust image registration for compositing high dynamic range photographs from hand-held exposures. Journal of graphics tools, 8(2), 17-30.