darktable

darktable is a raw developer and photo workflow application. It leaves the original file untouched: every adjustment is stored as a list of processing steps in a sidecar XMP file or in the library database, so an image can be reworked or reset at any point without a second copy on disk.

The interface is split into views. The lighttable is where images are imported, rated, tagged, filtered and grouped; the darkroom is where a single image runs through a stack of modules covering exposure, tone mapping, colour balance, denoising, lens correction and sharpening. Most modules accept drawn and parametric masks, so a change can be limited to a shape, a colour range or a brightness range. Colour management runs through ICC profiles, and heavier operations can be offloaded to the GPU with OpenCL when a supported driver is present.

darktable also drives cameras over USB for tethered shooting, and exports in batch to files, folders or configured storage targets.