Compress the history stack of many images at the same time


(/ar) #1

Typically in my workflow, I start with a large set of pictures I end up with a few flagged for post-processing and then exporting. In difficult images I often try different things in darktable mode, sometimes going back and forth. The history stack can grow quite a bit. Often, once I get the result I wanted I just move on to the next image - I forget to clean up the history stack by clicking compress.
I always wonder if, by not compressing the stack, pixelpipe processing takes longer and/or the image quality can get degraded unnecessarily.

Anyways - I’m looking for a way to “compress the history stack” in batch mode for a set of selected pictures. Couldn’t find the way to do so - is there a way?


(Mica) #2

I don’t think it makes it slower, it has to do with how/how much it is stored in the database/xmp files.


(Roman Lebedev) #3

https://www.mail-archive.com/darktable-dev@lists.darktable.org/msg02807.html


(/ar) #4

Thanks! big relief :), and it seems Compress History Stack OCD peaks in New Year’s time and it’s not just me being affected :slight_smile:

I understand now the purpose of keeping the stack under normal situations and that it’s length/complexity won’t affect image quality or (I assume) processing time, and that a mass “compression” without a warning can lead to ppl losing the top end of the stack if their image was pointing to the middle of the stack. So clearly a ‘module’ to keep it compressed is not the right approach.

Now in the lighttable, there is a panel with disruptive stack operations that can be applied to image sets (like Discard, Paste+overwrite etc) that provides warnings &c as needed. Understanding that compression is done only for cosmetic reasons hence zero priority… it could be nice to have the Compress option in the stack operations panel, if only to help people going through a History Stack OCD period :slight_smile:


(Peter) #5

Any solution of compressing the history of many raw files? Sometimes when I edit some raw files on my memory card, the history from the last shot on the same card and same file nr messes up the xmp files. I can get a history of 500 steps and darktable crashes due to it.
Compressing of history clears it up, but to clear the history of 200 pictures one and one are not the way I want to go.DJI_0051.DNG.xmp (176.5 KB)
DJI_0051.DNG (23.2 MB)

EDIT: Found the over write feature in lighttable. Problem solved.