Multipass sharpen - large images?

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MarkT
Posts: 366
Joined: April 24th, 2009, 2:07 pm

Multipass sharpen - large images?

Post by MarkT »

Hi,

So I tried a 2-pass Multipass sharpen on a fairly large image - 25200 x 16800 pixels - and my computer froze. Nothing seemed to have started, no status bar appeared, but I couldn't do anything. Waited 15 minutes to see if anything would happen... Ctrl-Shift-Del/Ctrl-Alt-Del didn't work, so I had to unplug the power and reboot.

It's probably my setup: Win 10, i7-4770, 8GB RAM. Not enough memory to play with and not enough horsepower to handle the processing?

But I'm wondering what image size limit would be acceptable. The original image is 8288 x 5520, and the same Multipass sharpen operation takes less than 5 seconds to complete.

Thanks.

Mark
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: Multipass sharpen - large images?

Post by jsachs »

The Guided filter does create a number of temporary copies of the input image, stored as 32-bit floating point so there is more of a memory load while it is running, especially if the radius is < 4. You might try upping your swap file size so at least it would not crash even if it gets slow. Or you could switch to Bilateral filter which uses less temporary storage.
Jonathan Sachs
Digital Light & Color
MarkT
Posts: 366
Joined: April 24th, 2009, 2:07 pm

Re: Multipass sharpen - large images?

Post by MarkT »

Thank you for the suggestions. I switched to Bilateral filter, and after about 10 seconds the thumbnail for Multipass Sharpen turned red and displayed "err: illegal input image type". The image was a 48-bit TIFF, so I converted to 24-bit and ran MS again. This time after about 15 seconds, the thumbnail turned red and displayed "error".

I reduced the image size to 12600 wide, and ran MS, this time without any errors. It took about 10 seconds to run the two-pass operation, so I'm assuming my system is just not up to the task with really large images.

Update: I checked my virtual memory settings:

"Automatically manage paging file size for all drives" is checked
Minimum allowed = 16MB
Recommended = 1912MB
Currently allocated = 4549MB
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: Multipass sharpen - large images?

Post by jsachs »

Given you have 8GB of RAM, a 4.5GB swap file is not going to help much, but really you should have a lot more RAM if you are going to work with images that size.
Jonathan Sachs
Digital Light & Color
MarkT
Posts: 366
Joined: April 24th, 2009, 2:07 pm

Re: Multipass sharpen - large images?

Post by MarkT »

Yes, thank you for the confirmation. Luckily I don't play with files of this size very often...

(on the other hand, I am looking for an excuse to upgrade the desktop...)
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