Image on one monitor and controls on another - is it possible?

Hello! I am very glad with my first steps in rawtherapee, but i miss one option badly - i have two screens - one 1080 and one 4k, in fresh versions of darktable (3+) there is nice button, that opens current editing image (“image preview”) in new window, that can be moved anywhere (on second screen in my case) - are there any plans for such simple but very useful option in RT?

p.s. “own window mode” does not help, because it leaves controls and image in one window

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There are currently no plans for this. Also, while RawTherapee is by no means ‘slow’ software, rendering two outputs of possibly different zoom-levels and high resolution, is presumably going to be an unpleasantly slow experience…

Edit: well, what do you know, there is still an open issue about something similar on the bug tracker Detachable floating toolbox · Issue #4775 · Beep6581/RawTherapee · GitHub

I’ve long wanted the same feature myself, but unfortunately it doesn’t seem possible at this moment.

However I made myself a small RawTherapee patch that partially solves this issue:

  • if the environment variable RT_PREVIEW_PROTO is set to png or jpeg,
  • and if the variable RT_PREVIEW_PATH is set to a file path,
  • whenever the preview changes inside RawTherapee main window,
  • the pointed to file will also be rewritten with a large enough preview (between 1920 px and 3840 on the largest side);
  • then I just open that preview image with any tool that supports image reload; (for example sxiv and geeqie; ) (optionally color management should be supported by that viewer and the proper profile should be loaded;)

The patch is quite small and available on GitHub:

(As bonus point, if the preview path is on a remote file-system like NFS, or exported via HTTP, you can preview it on any device.)


That being said, as @Thanatomanic mentioned, it does come with some performance penalty mainly due to the large preview size. You can improve that performance by decreasing the nWH_min variable to a more sensible value.)