Noise reduction - unsharp mask - CS2

I have a question for the techie types here.
I notice that when I do a large batch process for noise reduction (using actions) in CS2 that the time involved is dramatically longer than it takes to do a batch action 'resize - unsharpen mask - convert color space- 8 bit mode- save as' (using the exact same batch side)
I am curious as to why CS2 noise reduction takes much much longer than all the other actions combined?
Is there something about noise reduction that requires more memory or CPU processing?

Not sure which Noise Reduction you are using, the PS version built-in or a plug-in. But yes some just take more time then others.

I'm using the CS2 built-in version.

Do plug-ins work faster? I have just spent the last week leaning sharpening - I don't think I have the energy to learn the intricacies and nuances of noise reductions right now

philmar wrote in post #3189289
I'm using the CS2 built-in version.

Do plug-ins work faster? I have just spent the last week leaning sharpening - I don't think I have the energy to learn the intricacies and nuances of noise reductions right now

I don't think that plug-ins work faster. I use Noise Ninja and it takes some time to complete the task. Granted my PC isn't the fastest but I don't use it enough fro it to bother me. Noise was something I used to worry about but very rarely do I use it now.

Anyone know why noise reduction takes longer than sharpening?

Perhaps because sharpening occurs only on pixels on/near edges whereas noise occurs in much larger areas like shadows forcing CS2 to do a lengthier set of pixel related mathematical calculatiuons?

philmar wrote in post #3189856
Anyone know why noise reduction takes longer than sharpening?

Perhaps because sharpening occurs only on pixels on/near edges whereas noise occurs in much larger areas like shadows forcing CS2 to do a lengthier set of pixel related mathematical calculatiuons?

It has to be because of the algorythims. Try a more complicated sharpening tool like the TLR sharpening scripts and noise reduction will fly compared to it.

When I use The Noise Ninja plug-in with CS2 on a single shot, it takes around 3-5 seconds to complete the task. Multiply that out.