I hope this helps some others like me who want to convert a whole bunch of files from RAW to some other format. Darktable will then export the files in TIFF (or whatever) format.

Click the EXPORT button in 'Storage Options' - see Step 1 above.

NEF do dcraw -c -w 'filename' pnmtopng > 'filename.png' done. To convert an entire directory: for filename in.

Alternatively, use the SELECT ALL option near the top-right of lightable UI. Convert all NEF images to PNG: dcraw -c -w input.NEF pnmtopng > output.png.

Sadly, you can't see this very well on the screenshot, but I hope the reader understands the strategy. For this test, I used the same RAW image with different filenames (1300875350_fuji-x100-dscf5613.RAF, 2300875350_fuji-x100-dscf5613.RAF, 3300875350_fuji-x100-dscf5613.RAF). The images themselves are sitting on an OCZ Vertex 2 which can feed some 200MB/s+ - if secondary storage was the limiting factor then it would convert all hundred or so images in under two seconds. Use CTRL and LMB to multiple-select RAW images.

Select all of the images you wish to export / convert.

Set the desired path for file export to disk, and conflict options.

Open up 'Storage Options' in 'lighttable' section of Darktable, set the required settings.The process can be adapted for your own conversion requirements, but I wanted 8-bit TIFF - the reason why is irrelevant. Value of 0 means most compressed and 100 means lossless.After some exploration, it is actually quite straight-forward. Here, the formatOptions argument sets output quality for the image. This command will convert images to heic and put converted images to 'converted' folder. for i in *.jpg do sips -s format heic -s formatOptions 75 $i -out converted/$i.heic done HEIC images will be 30-50% smaller for same quality as JPEG. It's also possible to convert all jpeg images to HEIC to save space before storing them. This command does not take multiple inputs but it's super easy to convert multiple files with shell scripting: for i in *.png do sips -s format jpeg $i -out Converted/$i.jpeg done To convert single file with sips, here is command syntax: sips -s format -out įor example if you want to convert file named test.png, here is sips syntax: sips -s format jpeg test.png -out test.jpg There is however a very handy command line utility called sips that comes built-in macOS and provides an easy way to convert thounsands of images in efficient manner. Opening thousands of images and then converting them using preview will mostly end up hanging mac for saveral minutes. This becomes a problem if you ever want to convert large number of images.

This article by MacRumors describes an easy way to achieve it. MacOS preview application provides a very easy way to convert and process images if you want a quick way to convert a few images.

Nef to jpg batch converter commandline