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I have updated Turbulent Halftone as well. It will give better quality results and you now have the option to use oversampling to get an anti-aliased result.
There is also a new filter in my testing folder call Split Details [Orientation]. It creates a high pass and low pass layer, but the high pass layer is only the details that are in the given orientation. Simply put, it means you can pull out, say, only horizontal lines, or lines that are within X degrees of horizontal.
It looks like it will be really helpful at hair retouching because you can choose to add the hair orientation to the residual and reject the hair the is not aligned with the rest.
I went to look at your filter beta and refresh didn’t seem to pull down what you have in the screenshot.
does this also require beta of gmic?
the version of the beta filter I have now I’ll note I do like. biggest thing I have to watch for is swirling from it.
I think I didn’t push the right button in my Github software. I’m not sure exactly what the correct process is but I have pressed more buttons and it seems to be updated on the GMIC GitHub so it should be available soon.
If not here is the file. iain_fergusson.zip (40.2 KB)
there is an example and the raw its based on if you want to play with this horrible test
ill check for your update tomorrow sometime or grab that zip if its not ready by the time I am.
In the new beta the ‘soften guide’ will help reduce this. This is a very small amount of blurring on the guide image which stops the filter from thinking small specks are details rather than noise.
In the old beta, you can still do this by using an external guide that has a small amount of blurring. Just put the blurred image below the noisy one, selected the noisy layer in GIMP and in the GMIC plugin, set ‘Input Layers’ to ‘Active and Below’
Using an external guide is very flexible and you can experiment with using the result of a different denoising filter as a guide to improving the results in my filter. For your image, I would recommend using a median filter (especially on the red channel) rather than a blur.
Also, with an image as noisy as yours, I would recommend using a higher value of ‘Lookup’ (but this will be slower).
Edit: You can even use the output of my filter as a guide to a second pass.
thank you for your amazing filter(s).
now that I know how to better use it I find the results even more amazing
I consider the image junk and have mainly kept it as a test image to see if I can ever clean it up
to have it recoverable to this level with minimal effort is impressive.
below is before and after of a cropped area
did some experimenting, doing pixel denoise and hot pixel removal
then downscaling 50% and doing the median filter on red blue then green then scaling back
seems to provide best balance for most part.
I would need to look to find the info but as I recall with iso3200 on that camera the useful resolution is half normal so ending up afterwards down 50% in size is likely to be expected
and to be honest with that kind of shot and that camera’s bad noise pattern I would say needs tripod and several shots to stack
but for a 75$ toy one needs to work harder
@Iain: btw you might want to add at the bottom of the config window some help text on how/when to use the external guide image.
until this forum thread I didn’t know how to use the guide.
I did try the updated filter, the ‘soften guide’ does help, I think for quick likely lower noise pictures I would use that option.
I still find using the external guide is more effective since I can control the soften effect
as such I find myself more pondering ways to pre filter noise like the red channel issues