darktabIe-generate-cache

Software darktable
1

I have darktable on a mac and have been reading about thumbnails and saw a reference to a binary called darktabIe-generate-cache but I can’t see it on my system. Where could I obtain this, please?

I have most images on an external disk drive and noticed that when this is disconnected, DT still displays the thumbnails for some of them - not sure why only some?

I wondered if I connect the external drive and then run darktabIe-generate-cache if it will create all the thumbnails, so I can at least see those when the disk drive is offline.

Thanks

Lee

2

The binaries on macOS are locates inside the app bundle, so you can cd /Applications/darktable.app/ && ls -al.

3

Do some exist on a connected location. The DT database only knows about the location of the file when it was imported or moved within DT if you disconnect you will often get skulls showing as it has no idea where the file is however there is a feature to work with external drives and disconnected media… darktable 3.4 user manual - local copies

You might find this useful as background… https://www.youtube.com/watch?v=CGpbiXFcxZ8

4

Thank you both for your help - this is great.

Lee

5

This has worked really well. I just wanted to be able to quickly view images located on an external drive when that drive is not connected to my laptop. With LR, there are ‘smart’ previews’. So I started with that idea and quickly got my LR catalog up to 100GB, most of which were smart and standard previews and I had not even finished importing everything.

So with DT I used

darktabIe-generate-cache -m 3

and I have thumbnails big enough so that I can view them 4 across in Lighttable view with no side panels. The thumbnails folder is 16GB in size, so this is quite respectable.

I can now see reasonable size thumbnails of all my images, tag the ones I want to work on in some way, then connect the drive and make local copies. Brilliant!!

BTW, without the ‘m -3’ option, the thumbnails folder was only 5GB but if I tried reducing the number of thumbnails across or remove the side panels, I would quickly see skulls, so I tried ‘m -3’ as a test and it seems to work.

I assume that -m <higher_number> gives you bigger thumbnails?

Thanks again for this very helpful forum and, of course, the developers for darktable.

Lee

6

Yes, from https://darktable-org.github.io/dtdocs/special-topics/program-invocation/darktable-generate-cache/ :

–min-mip <0 - 7>, -m, --max-mip <0 - 7>
darktable can store thumbnails with up to eight different resolution steps for each image. These parameters define the maximum resolution which should be generated (defaults to a range of 0-2). There is normally no need to generate all possible resolutions here; missing ones will be automatically generated by darktable the moment they are needed. When asked to generate multiple resolutions at once, the lower-resolution images are quickly downsampled from the highest-resolution image.