Hello everyone.

So, there's "Smart Canvas" in Krita: https://youtu.be/xpWmQ-OY36I

Is there any way to automatically apply Smart Canvas to a collection of images?
Provided all the images are located in one folder and have the exact same resolution etc.

Basically, I have a watercolor animation. It's almost 2000 frames,
so manual drag and dropping of each individual frame into a Smart Canvas project (.kra) and re-saving is just off the table for me.

Maybe it can be done via some script or something?
Let's say, I specify a folder, and Smart Canvas is being applied to each image inside the folder automatically?

You might be able to script it, but there's no ready-made script available, and I'm not even sure how I would approach writing one.

I guess the best way to add a paper texture to your animation is by using some video editor (Kdenlive/Blender/etc). Just overlay the texture (Blend Mode: overlay).

It doesn’t have to be a seamless texture with repeated pattern.
There are also public domain and CC0 textures online with big resolutions.

Maybe someone will find this information useful.
I've found a tutorial for Affinity Photo with good general advises: https://youtu.be/K3tCajXSjUw
You can repeat all those steps in Krita.

1. Desaturate your texture, remove color, make it white and black (Filter - Adjust - Desaturate).

2. Change the brightness of your texture, make it as close as possible to middle gray,
so the texture won’t brighten or darken your artwork.

According to this article https://en.wikipedia.org/wiki/Middle_gray
Middle gray in sRGB is (128, 128, 128) or #808080
Middle gray in CIELAB is (119,119,119) or #777777

So, yeah, open middle gray color in a reference window,
blur your texture non-destructively (with a Gaussian blur filter layer),
compare it to middle gray (with your eyes).
and adjust the texture’s brightness (with a Levels filter layer).
And then just remove the blur filter layer.