I would like to print some of my original artwork on large paper and am having difficulties recreating some filter effects on large file sizes. The Inkwash layer in particular.
480 640 image on the left and 3000 4000 image on the right.
Is my artistic vision doomed to small prints?
I think that would have to increase the effect 500%
I had similar thoughts, unfortunately all the sliders aren’t suitable. I have no experience scripting but like my art enough to give it a go ~ So as the song says, ‘Where do I begin… ?’
Thank you for your reply!
Do you know what the original values for the sliders were?
I’d start by adjusting the amplitude, and work your way from there. You might write a simple bash for loop that sets the values of a few slides and increments them and outputs several different images, that way you’d be able to see at least when you’re getting close.
You might also check (how to emulate ) Ink Wash • GIMP Chat
Here are the default values for 960 1280
These results are tweak~ably acceptable
I’ve been trying for a week on the larger 3000 x 4000 and can’t get anywhere close.
Sorry, I meant the actual numeric values for the g’mic sliders.
Thanks for your reply, sure, the default numeric values for the sliders are: Size 0.14 / Amplitude 23.00 / Smoother sharpness 0.50 / Smoother edge protection 0.54 / Smoother softness 2.25
Hello,
PhotoComiX is the author of the InkWash filter, so he is the one who could tell. Unfortunately, we haven’t got news from him since a very long time now.
Anyway, my humble opinion is: the filter relies on anisotropic diffusion which is a purely local process: it locally smooths the image according to the shape of the contours. So, there are probably no easy ways to find appropriate parameters for images with any kind of resolutions. That’s being said, as the filter creates very smooth results, I suppose you can render your effect at the resolution you think it renders best, then upscale the result afterwards with some basic interpolation methods (as you apparently want a smooth result, upscaling won’t be a problem regarding the detail loss).
One step further : it would be interesting to apply the inkwash filter for several increasing resolutions of the same input image, then blend all the results for all these different resolutions together. For this purpose, you can use the G’MIC filter Layers / Multiscale operator, like I did in the screenshot below:
(my input image is 2000x1400 here, I let the default settings).
That way, you can adjust what level of details you want to see in your final image by playing with the opacities/modes of each of the rendered layers.
Just my thoughts on this.
Thank you for your reply. Two excellent suggestions. I am interested to hear your opinion about best quality images using basic interpolation methods when upscaling. Thank you for your time.
In your case, for upscaling, I would suggest a simple Lanczos filter.
But if you wish, you can try a more advanced upscaling method (there is one in G’MIC, filter Repair / Upscale [diffusion], but I’m not sure this is necessary here).
Thanks again, the basic interpolation might be acceptable. I will try a few test prints. Here is the result after scaling and colour. 
