Feature #9715

website - Feature #8747: new sharing platform for dt styles

Style previews

Added by Jesko N about 6 years ago. Updated over 5 years ago.

Closed: won't fix
Target version:
Start date:
Due date:
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Estimated time:
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Saved styles are a great way to apply predefined effects (such as Sepia, Lomographia, different kinds of B&W conversion, ...) to images.
However it is often hard to predict how the processed picture will look like finally. That means you have to apply the styles one after another to the image in order to find the style which looks best.

It would be very helpful to provide a tiny preview image of how the image would look like after applying the style (similar to e.g. the effects preview in Picasa). The preview could be displayed next to the filter list which pops up when hovering a style (in both the fast style access in darkroom and the style list in lighttable).


#1 Updated by Simon Spannagel about 6 years ago

  • Parent task set to #8747

this is related to ticket #8747. already in preparation, even though not part of darktable itself. but i don't think such a feature would make sense in darktable itself.

#2 Updated by Jesko N about 6 years ago

I think this feature would be very valuable in DT itself because how a style affects the image strongly depends on the base image (e.g. if a style applies conditional masks the result can be strongly influenced by the color of the base image). IMHO the final result is hard to predict without trying to apply the style or getting a preview.

PS: Simon, there's a number twist in your comment. ;)

#3 Updated by Simon Spannagel about 6 years ago

  • Status changed from New to Closed: won't fix

Oops, thanks for mentioning... :)

However, I see where you want to go with this but I don't agree:

If your style affects the image in a subtle way e.g. through (unpredictable) application of conditional blending you won't notice that on a small thumb image, so you need a larger preview. What then exactly prevents you from just applying it to the image itself (or a duplicate if you want to play?) I mean it's your styles and not some random ones you are dealing with here, so you should be able to estimate the effect and pick the right one at least.

Furthermore the thumb displayed would have to be processed. This is either slow to display (want to wait ~1sec every time you check a style?) or would have to be preprocessed and cached - but for what? Every image with every style possible? Not feasible as you might agree...

So, I guess this is a classical "Won't fix" candidate. Feel free to comment.

#4 Updated by Jesko N about 6 years ago

Thanks for your answer.

I think that many users have a long list of styles - some of them created by themselves, others imported from the internet. A visual preview helps to predict how the final image will look like - that's why Lightroom, Picasa... show previews for styles/effects as well.

I agree that caching would complicate things too much. It would be sufficient to calculate thumbnail previews asynchronously (showing a spinner for ~1sec) when hovering the style and then to show the thumbnail in the tooltip.

IMHO it's not usable if users need to create duplicates in order to play with styles and finally apply them to the original image. Directly applying styles to the base image has the disadvantage that certain style tags get added automatically to the image (and remain there even if the user undoes the applied styles unsing the history stack). And experimentally applying several styles one after another is really time consuming.

That's why I hope this ticket can be treated as a "To-Fix" candidate ;)

#5 Updated by Robert Rosman about 6 years ago

I think Jesko has valid point here to take into account. It would be time consuming to generate preview images every time, but wouldn't it be significantly faster to apply them on a thumbnail?

I understand the objection that small nuances won't be noticable on thumbnails, but with styles downloaded from the internet, especially once #8747 is implemented, it won't be obvious what the styles will look like only by reading the style's name.

My proposal: Have a button in the styles module called [preview], that shows a new dialog containing thumbs on the selected image, with all different styles applied. Before the styles are applied a copy of the selected image can be scaled down to make the processing faster.

The thumbnails will probably not be super accurate, but at least they'll give a hint about how the style will affect the image.


#6 Updated by Robert Rosman about 6 years ago

After playing around a bit in dt I realize a couple of things:

  • The difference in processing time isn't that big between a fullres image and a thumbnail.
  • There a huge difference in the output depending on whether the style is applied to a raw file, a jpg file, a tif file etc. Therefore the preview images must be the same format as the original image.
  • It will take time.

If I would implement this feature, the processing would probably look something like this:

  // Note: only pseudo code
  history = image.history
  foreach style {
    image.history = history

And it would take time. It would probably be syncronous. Is there any way to speed this up?

#7 Updated by Kevin Unhammer over 5 years ago

I agree this would be very useful even if the results are not "exact". Lightroom 4 shows a thumbnail preview on hover (actually a full one as well if you're in the Develop thing), and it's enormously handy if you've got a huge number of styles/templates from the 'net where you don't have a clue what any of them does – you can fairly quickly go through the list until you find something that looks close to what you're after. When I tried going through styles downloaded from I found it too tiring to do the "apply, remove" sequence for every style and ended up not using any of them.

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