HDRMerge vs rawhdr

HDRMerge combines exposure-bracketed raw files, or bracketed frames within one raw file, to create raw images with extended dynamic range. It outputs DNG 1.4 images with floating-point data, drawing on less noisy input pixels to retain shadow detail. In its graphical interface, users can adjust the merge mask to address ghosts from objects that moved between exposures. The command-line interface supports batch processing of raw image sets. HDRMerge can align small translations and crop the output to the area shared by the inputs. Input images must match in size, orientation, Bayer pattern, and black and white levels; the manual says this usually means using images made with the same camera. Tone mapping can happen later in another program that supports high-dynamic-range raw DNG images. The maker identifies RawTherapee, darktable, and recent Adobe products as supporting the floating-point DNG output. HDRMerge is free software under the GNU General Public License, version 3 or later, and runs on Linux, macOS, and Windows. The maker describes it as a way to bring merged HDR images into a standard raw development workflow.

rawhdr is a free command-line package for combining multiple RAW photographs into a high-dynamic-range image. It also performs focus stacking from multiple images. RAW input can use formats known by the rawpy library, while output can use HDR formats known by imageio. The resulting HDR exposure follows the first RAW file supplied. Installation is documented with pip install rawhdr, and a Python API is available for exposure merging and focus stacking. Its exposure-scaling helper leaves out extremely bright pixels that may be saturated and very dark pixels that may be noisy. OpenEXR writing may require the additional freeimage library through imageio. Python 3.7 or newer is required. PyPI classifies the package as OS Independent, with Linux and API listed as platforms. It is licensed under the GNU General Public License v2 or later. PyPI names Felix Thaler as author and maintainer.