Extending image-grouping with image-alignment/registration to implement super-resolution, (HDR) or focus-stacks
I appreciate darktable already supports "HDR", but this requires precise alignment between the input images and doesn't specify how the HDR is to be computed.
I'd very much like to see this extended to support 3 ways of blending image-stacks:
- if the images have varying spatial offset (hand-held jitter) then align_image_stack or cpfind etc can be invoked to give a larger image with lower noise - stacking for superresolution, ie the pixels from one interleave and overlap with those from another; enfuse --entropy-weight=1 will handle the blend.
- if the images vary in exposure, we have HDR - enfuse --exposure-weight=1 will handle it.
- if the images vary in focus distance, we have focus-stacking - enfuse --contrast-weight=1 will handle it.
What I would really like is to be able to smoothly select a group, then from a control in the right menu be able to select which of the above are applicable: upscale (by a proportion, eg 1.33x) or not; needs alignment or not; needs exposure blending or not; needs contrast blending or not.
At the moment, my workflow involves a phase a RAW conversion, grouping the TIFFs into subdirectories, running align_image_stack and enfuse per directory (mostly a hybrid combining entropy and exposure blending), moving the results all back together and running darktable for finishing. Being able to do the whole process in darktable would be an epic win.
#1 Updated by Anonymous over 2 years ago
I too would love this. Though there are quite a few possibilities in configuring the tools, see e.g. http://blog.patdavid.net/2013/01/focus-stacking-macro-photos-enfuse.html for several possible enfuse settings for focus stacking. And align_image_stack should be run with -m (to make it correct field of view) for focus stacking, and there's also the switches -dixyz for other kinds of corrections (radial distortion, image center shift, and camera XYZ position).
#3 Updated by Ted Hennicke almost 2 years ago
+1. I strongly support this feature request. IMO the biggest weakness in darktable at the moment. It would be lovely to use enfuse to create a seperate DNG file in the same way that HDR merge works at this point. The command-line tools already exist so this should be relatively easy to implement. Indeed I believe it has already been done, but I don't read german: http://www.multimedia4linux.de/index.php/bildbearbeitung/darktable/darktable-plugin-enfuse-professional
Please please please put this on the roadmap :)