Multiple Adjustable Component Output ?

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jffe wrote: If I'm in the middle of a filter, wiring it up, and say I want only some of the blurred (..) image created thus far going to a 2nd component, how can I do that using only 1 blur ?

I'm not sure I understand what you're saying here.. blend the parts you want blurred and blur them? Assign the different sources to different channels, blur them and extract the channels (given its grayscale)?

ah I see.. you want different blur radii outputs...

Well, for rather simple inputs you could simply adjust the output using different curves. E.g. if the background is black, you could adjust the blackpoint and gamma..
This won't work for high frequency inputs though, as the features would melt together

consider a white circle on black background... you want blur radii outputs of 2.5 and 5.. you blur it using 5, and then adjust a copy output to blackpoint around 50... this contracts the visible range roughly to the half.

you could also re-map the blur output individually... use one blur into two components, but re-map each.

Assuming we want to have an image blurred at 5 radius and 2.5 radius, two possible ideas (which give maybe not exactly similar results to the image jffe used above, but fairly close) might be:

1 Chain two blurs each at 2.5, where the second blur would look very similar to a blur with 5 radius. (So the total blur radii calculations aren't 7.5, but just 5).

2. Use one blur at 5 radius, then for the 2.5 radius, blend the 5 radius blurred image over the source image at 50% opacity. (So the blur calculations still only add up to 5 radii, and you use a quick blend component -- which I'm guessing may be faster than calculating 7.5 blur radii.)


(I'm not sure I spent enough time trying to understand the question, but this is what I imagined so far...)

jffe,

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----And since ssamm guessed it, my way was exactly his #2 suggestion,

Yay!
I probably wouldn't have thought of it, if you hadn't posited it as a question, though.

I think it's a nice practice to try to see how we can reduce render times with filters -- since for me, long render times tend to turn me off from further experimenting with certain effects...

::blinks at this post, and then skulks back to her 'I use curves sometimes... I swear.' place, where she has cheerios. ::

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jffe wrote: And since ssamm guessed it, my way was exactly his #2 suggestion, blend the blurred 5 with it's unblurred self, for an approx. 2.5 blur then going out to the 2nd component, thusly getting 2 *Blurs* for the price of one.

Hmm.. So you simply blend a blurred source with the unblurred source... I can understand how this would work for radii < 1.. but > 1 it seems like a rather far fetched approximation... think of radius = 50.. blending that 50% on the source doesn't give something that looks like 25.. it gives you a semitransparent blob

Let me try that tonal remapping approach I talked about.. I'll post a an example later..

after

faux radiusmap