Bulk Processing

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steve_s

I am fairly new to Darktable and this is my first post in this forum. I don't seem to find any previous discussion that addresses my particular interest -- automating some of Darktable's processes to apply them to an entire series of images at a time. The History Stack technique doesn't seem to work for what I need.

Part of my photography activity is to convert old negatives and slides into high quality computer files -- RAW and JPG, and so far I've done about 24,000 conversions and a typical run is somewhere between 500 and 2500 slides.

My software of choice up to recently has been GIMP automated with BIMP which does much of what I want -- I can automate basic corrections on an entire folder of images in one process. The downside to GIMP is that it will not process RAW, which means I must accept my camera's processed JPG files as a starting point and that is far from ideal.

Darktable is great because I can start out with RAW files and do an Orientation on them right away but after that, things are not as I would like. A quick-and-dirty correction that works well is to use the Color Balance's Optimize Luma and Neutralize Colors buttons to brighten and color correct each image, and I can do that one image at a time but that's tedious.

My first desire is to find a way to automate that process -- to do the Optimize Luma and Neutralize Colors for each image in a folder in one step.

After that, as of now, I have to export to TIF (to keep detail but make the image readable by GIMP) and then use GIMP's BIMP plugin to do a levels stretch and finally export as a JPG.

I would like to ask if there is some capability in Darktable that I am overlooking --a capability built into Darktable that will allow me to run the Color Balance automation against an entire folder full of images automatically.

Ditto, I need a levels stretch capability in Darktable that I could run in conjunciton with the Color Balance steps that would allow me to make all the above corrections and eventually export directly from Darktable to JPG with the corrections all done.

Worst case I can switch to GIMP for the Levels Stretch but would still like to automate the Darktable Color Correction process.

MrSteveVee

Option 1: Make edits to first Image in darkroom view. Go back to Lightable view, Ctrl-C on the amended image, select all images to develop, Ctrl-V to paste the changes to them
Option 2: Make edits to first Image in darkroom view. Go back to Lightable view, click amended image, go to right hand side, under the history stack tab select copy (or copy all). Hightlight all images to develop, go to history tab again and select paste (or paste all)
Option 3: Make edits to first Image in darkroom view. now look at the history stack in this view and there is a "Compress history stack" look on the right hand side of this and there is a little icon that looks like bubbles, Click this and you can create a style from tyhe history stack. Now when you are back in lightable view, select images to develop then on the right hand side there is a "style" option, your style should be there and you can pick this to apply the same style to all the images
If you have several tasks that need to be applied to some or not all in certain combinations, then option 3 is the best as you can build up a style to perform a specific set of edits and pick the ones you want for given scanned images
Have fun,
Steve

steve_s

MrSteveVee

Thanks for the reply! I've been with Darktable long enough to know about these techniques and I use them, and I've created styles for CW, CCW, and 180 degree Orientation moves, for example, so I can click through a hundred images and get them all upright in short order.

What I am trying to do is find a way to correct and enhance color of all RAW images in a folder.

With GIMP there is an add-on called BIMP that enables me to select multiple automatic corrective features of GIMP, and apply them consecutively to each image, but the automated correction is executed for each image without regard to results obtained from a previous image.

In Darktable, however, when you do a Levels Stretch on one image and apply that to all the other images, it appears to me that Darktable applies the resulting values of the first stretch to all the other images rather than doing a from-scratch automatic Levels adjustment to each of the images selected. It doesn't make sense to apply the change values from one image to all images because each image needs to be measured and corrected individually.

I am looking for a method whereby I can run an automatic color correction on each image, not to apply one color correction to all images in the list.

I do like the "optimize luma" and "neutralize colors" buttons in the Color Balance module as an excellent starting point when processing many images that need to be "pretty good" not superb, but I hate stepping through a hundred copied 35mm slide images and clicking the two buttons for each image.

If there is no current answer to my need, is there a way I can request the capability be considered in a future release?

MrSteveVee

Hi, we are an independant forum and not affiliated with darktable unfortunatly but if you go to their website on darktable.org I believe there is a link there for suggestions and improvements.
Hopefully another of our members can help with your questions. Personally when I scanned in aroundd 10K images I would pick one, adjust brightness etc then just apply it to all images that looked of a similar exposure so that they were all "good enough" to view on my monitor (I use the lounge TV lol), as mine are all persoal family so I only display them and by the time I am half way through a showing, everyone has fallen asleep !!
Steve,

jaw-dt

Is there any way an auto applied preset would do what you need?

steve_s

jaw-dt

Not sure what you mean by auto preset but, what I want to do is auto-correct each image independently of every other image. It appears to me that in darktable right now if you run an auto-correct on an image and then apply that to all the other images it applies the result of the original auto-correct rather than auto-correcting each image one at a time.

In GIMP auto-correcting each image independently can be done with automation, thus every image in an entire folder or even folder structure can be auto-corrected based on the need of that particular image. Much, much better than correcting one image and then applying that singular correction to all of the images in a folder.

Right now I use darktable to take RAW images from my camera -- which gives me much better images to start with by avoiding camera-produced JPGs -- and within darktable I correct orientation and do basic color and luma correction and output that result as a TIF which GIMP can read. I then use GIMP to level stretch the TIF image and output it as a JPG. The 24 megabyte RAW ends up as a 7~10 megabyte JPG with good color and good resolution. I'd just like to skip the TIF step if possible.

I'll see about asking for the capability at darktable.org but darktable seems to be focused on dealing with individual images singly, I think I am out of step with most users and I wonder how much attention I'll be able to muster for my off-the-path capability.

MrSteveVee

In a development module you can save the changes as a preset, when you save the preset you have the option to make the preset auto apply to other images depending on given criteria, that is what @jaw-dt was suggesting
Steve.

jaw-dt

Here is link to presets in documentation.