Re: [filter-effects] Color clamping of intermediate filter primitive results

This is what the discussion is about.

Greetings
Dirk

On Jul 24, 2013, at 6:33 AM, "Kristopher Giesing" <kris.giesing@gmail.com<mailto:kris.giesing@gmail.com>> wrote:

Hi Dirk et al,

Don't you get different results depending on whether clamping happens at each stage or only at the end?  It seems like this isn't just a performance question, it's a behavioral question.

- Kris

PS. I've been lurking on this list for a while now, but this is my first post. Hopefully I'm not overstepping etiquette by jumping in.

On Tue, Jul 23, 2013 at 4:41 PM, Dirk Schulze <dschulze@adobe.com<mailto:dschulze@adobe.com>> wrote:
Again, we are about a complexity from linear to a constant in many cases. I think that this fact is worth it to questioning the "always-clamp". Even with better hardware and GPU acceleration in the future, this would still be a win.

To your previous argument about the cache: Quite often the images are big enough to cause cache misses. And even if not, the speedup of one run in comparison to n runs over each pixel is huge.

Greetings,
Dirk