Why is the render taking so long

Yep...Some filters take longer then others to render the same image. This is due to the components in the filter itself...Some of the blurs are known for this....What filter is it that is slow in rendering?..

It doesn't sound like FF is behaving right. Renders shouldn't take 15 hours unless your image is ridiculously huge or the filter is ridiculously heavy.

The filter in question use some quite old versions of the components - perhaps if you rebuild the filter with "modern" editions it will speed up things

Some notes on this.

Are you using pro version? FilterForge is hevily CPU depependant, so having multiple cores (like 6 or 8 ) help a lot? Normal version uses only 2 cores.

FilterForge is 32 bit program and thus limited with it's memory use, have you checked if that's the issue? That much slowdown sounds a lot like swap-trashing...

Big blur filter (like this 70pix side = 70*70 = 4900) means that app needs to do a *lot* samplling... => try smaller Blur.

I have no idea if the newer filters have speed optimizations.. You should ask fiter maker if he's willing to tesr/make an upgrade. I could do that (it looks simple filter) but I'd ask author first fors permission.


Addendum:
My FF4-demo crashed while testing this, report sent. Looks like FForge has some memory handling issues.

Standalone version of FF. Using Midtone Enchancher filer on 14 Mp Photo with Bitmap aliasing option on.. Happened during saving to disk (aka final rendering).

Exception reported at thread 00002F48 'RenderingMgr 131A6C70/4':
<class XFW::Kernel::StdException> bad allocation

Graphics card speed gives no boost to FF4 since it does all rendering on CPU.

7000 pixels wide and I'd assume some decent aspect ratio .. Say 5000 Pix high? Let's do some math.

7000 * 5000 = 35MPIX

Assuming the entire imaged is blurred at once (note: I have no idea how FF works internally, this is plenty quesses).

35MPIX * 4 channels (with alpha?) 140 Million values of whatever format this program internally uses. I'd expect it to be 64-bit floats. => 1100 Megabytes per each image stage buffered.

Not to mention the workload of 140M blurs (with each having 4900 fetches+math).

So yes.. I think that you are hitting the upper bounds on the FF system.


IMHO you should ask this from the program authors. It may well be that there is a way to make things faster, but I'm out of ideas atm.

Yes, it is definitely mostly due to the large radius blur. Turning off the Gaussian checkbox helps some, or lowering the blur radius value, but the output will be somewhat different from the preset in both cases.

Then I lose the effect I want, lol. But as I said, I lowered the rez and it worked. I'll show the finished image here probably on Monday.

Thanks, guys

For large images, the filter should really be reworked.

Sparse sampling can be achieved using the scale-down-then-blur-then-scale-up trick -- I mean doing this internally in FF by adding those scaling steps in the filter editor. For example, if you scale down an image to 1/10th the original size then blur it by 1/10th of the original blur amount and then scale it up to 10X, you will only need 1/100th of the samples compared to doing the blur at full size. With no significant change in quality.

Wouldn't scaling up and down like that affect the resolution, ThreeDee?

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here is the final result ...

Very nice!

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Wouldn't scaling up and down like that affect the resolution, ThreeDee?

You wouldn't scale the main image, just the branch that gets blurred. I'll update the filter with a "Use Sparse Blur" option so you can see what I mean.

JoannaK,

The trick works internally in Filter Forge, you don't need to take it to another program.

It may seem illogical at first, but since FF samples from Result "backwards", the second scaling step (scale up) ensures that only 1/100th of the scaled down image is actually sampled and thus blurred.

An earlier discussion on the subject here.

The trick works as long as it keeps the processing in RAM as opposed to virtual memory (hard disc), so the suitable settings and maximum image size depend on the filter construction, the image size and how much RAM is available for FF.

Hi WillowRaven,

You're welcome. It will work better with large images now without having to anything but install the updated filter (Midtone Enhancer V2).

Glad to hear that you're finding use for the filters. Thanks for asking, but just knowing that they're useful to people is good enough for me. I checked out your website -- you have certainly made a lot of great looking book covers!

TD

If it's got the "Use Sparse Blur" checkbox option, it is the updated version.