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+--- Thread: Merge lightening strike video frames into one image (/Thread-Merge-lightening-strike-video-frames-into-one-image)
Merge lightening strike video frames into one image - jnoake - 06-13-2023
I have 7 video frames (saved as PNG) of a lightening strike who's main 'vein' persists over most of the frames but is also producing 'tendrils' that are different in each frame.
I want to make a single image that includes all parts of that strike over time.
I have imported each image in GIMP as a separate layer.
I have tried 'Merge Visible Layers', that basically gives me just the first image.
I have tried setting each image to 50% Opacity and then each image Mode to 'Merge' - which is the closest I can currently get to the desired end-point, unfortunately the grey in the clouds where the image does NOT include the 'tendril' tends to erase that from the image where that tendril IS present.
I have experimented with Add Subtract and Multiply but they all badly effect the overall background image.
I have no doubt that this has been done before, but Google and this forum search does not result in anything awesome.
Attached are a couple of the (reduced to 20%) frames that the effect is visible in.
RE: Merge lightening strike video frames into one image - PixLab - 06-13-2023
It would have been better if you gave us the 6 image (at 20% is fine), because it could be needed to have an "order" to get all the burst/veins,
anyway with 2 images try Luma/Luminance lighten only
[attachment=9922]
Then do a New from Visible from right click on the top layer inside the layer dialog or go to Layer > New from Visible
Above the new "Visible" layer put the next layer you want to "fuse" and do the same put it in > Luma lighten only, and so on > New from visible... etc...
Or instead of new from visible, each time merge them down by 2 each time instead of new visible
There are many other solutions, like get a mask (very easy on this type of image) to protect the trees, the roof and even the sky and have only the bursts.
RE: Merge lightening strike video frames into one image - Ofnuts - 06-13-2023
You can try puttin all layers (except the bottom one in "lighten only mode"):
[attachment=9923]
To improve this, once you have done that:
- Get the image as a layer: Layer > New from visible
- Duplicate that, and Color > Desaturate > Desaturate (Luminance)
- Start the Curves tool, the idea is to tweak the image so that, the whole sky becomes white, the lighting becomes black, and the trees stay the same
- [attachment=9924]
- Open the Channels list, right click any of the RGB channels; and Channel to selection
- Hide the desaturated layer, selected the first "New from visible", and decrease the brightness and increase the contrast.
[attachment=9925]
RE: Merge lightening strike video frames into one image - rich2005 - 06-13-2023
Well I have gone roughly the same route. Five consecutive frames @ say 25 frames/second and the background should be identical.
Frame 1 and frame 2 differenced.
[attachment=9926]
In a layer group and the difference layers over Frame 1 in Addition mode.
[attachment=9927]
Should be possible to create a combined image with succesive pairs of frames. (or maybe not)
RE: Merge lightening strike video frames into one image - Ofnuts - 06-13-2023
Another option is to also use one of the before/after frame **without** lighting (or to also combine all the frames in darken only mode) .
You can then subtract that frame from your lightning frames(*), and this leaves you with the lightning only. Then once you have these (added with lighten only mode) in a group, you can duplicate the group for added contrast, and put it over a darkened version of the lightning-less frame (which is much easier to work with because you don't have to protect the lightning).
[attachment=9928]
Exemple above obtained by artificially removing the lightning from one of the frames. Also cheated a bit because the top of the trees is reflecting the lightning.
Final note: its likely useful to use high precision mode for all this.
(*) ofn-interleave-layers can blend a layer against all layers in a stack with any blend mode)
RE: Merge lightening strike video frames into one image - jnoake - 06-13-2023
(06-13-2023, 01:57 PM)Ofnuts Wrote: You can try puttin all layers (except the bottom one in "lighten only mode"):
...
That's IT!, that's what I wanted, the Lighten Only mode was sufficient but I will experiment with your further suggestions when I have more time.
Attached is the result I was looking for.
Many thanks to all that replied, I will try each suggestion as a 'training exercise'.
RE: Merge lightening strike video frames into one image - sallyanne - 06-15-2023
'Grain merge' works too. So does 'inear burn' if you want the trees & rooftop dark