Alternative for the blur component

So I'm playing around with a filter I'm making and I want to add some blur to it but the actual component is waaayyy too slow. Are there any ways of getting the effect without slowing things down so much?

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As said above, maybe this offset construction suggestion could be done using a loop to increase gradually the offset to make the blur effect.

Basically this. But it's as slow anyway.

Well, the median component doesn't replace the actual blur one but it dose simulate the shallow depth of field look in photos which is what I was going for anyway. Here's a test render from the filter.

Here's a simple approach that improves rendering speed especially for large-radius blurs. Turn the radius up and down with and without the "fast" button clicked.

Fast Blur.ffxml

WOW!!ThreeDee this has been a clever and interesting way of making it faster, just reduce the original and then enlarge it back again to original size!!!

Congratulations on thinking of this and thanks for sharing it in the forum and help us with your knowledge and great ideas!

Although there is something wrong in your filter, the result from enlarging it is NOT exactly the same although quiet close, so I have tried to reduce the size of the radius in the scaled version to make it more similar to the original blur, but yet I have not found the exact number that will match the original blur

Instead of 10 in the remapping, I have tried 2, 5, 8 and 11 and 15 but gives slighty different results, will see which should be the better radius value that will fit to this so you get the closest result to the original blur in the same way that I got it right in the High Pass below

HOW MUCH FASTER IS IT?

Although there is something strange, when testing the filter with 600x600 images it is very clear that the fast version is really much faster and works smoothly, but I have tried to use a 7000x7000 image and the difference is not very high

Original Blur with radius 3 = 2 minutes

Fast Blur with radius 3 = 1 minute 44 seconds

I wonder if it could be that the difference in time is because both do not have exactly the same radius and the result is slighty different? Would need to make more speed test to know it

FASTER HIGH PASS

The best thing from this idea, is that this idea of scaling CAN be applied to OTHERS SLOW components, for example I have tried to use the HIGH PASS that is also slow and it works also well, and even better as I got the best radius value so both results are nearly the same, the difference here is really very, very little and almost identical

To get this I have reduced the remapping value from Maximum 10 to Maximun 2

In a 7000x7000 pixels:

The original High Pass takes 2 minutes 14 second

The new Fast High Pass takes 1 minute 45 seconds

Here is the Fast High Pass filter

Fast High Pass.ffxml

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SpaceRay wrote: the result from enlarging it is NOT exactly the same although quiet close, so I have tried to reduce the size of the radius in the scaled version to make it more similar to the original blur, but yet I have not found the exact number that will match the original blur

That's correct. It is basically just a dirty trick which utilizes the fact that blur is a bitmap-based effect. The only setting which will give you the same exact result is zero scaling. This trick works better with larger blurs; the larger the image and the blur radius, the greater the scale factor up and down can be.

It could possibly be made more "intelligent" by adding a script that calculated the optimum scaling factor from a combination of the image size and blur radius. But I haven't tried it.