Max. image size NI Vision?

[davi]

Hi Maclean,
Any news on this issue?
Thanks,
- Davi

[Maclean]

Hi Davi,

The size restriction is due to the operating system, and has nothing to do with the way Vision allocates the memory.  Vision is making malloc calls to the OS, which dolls out memory accordingly.  Attached is an example of the malloc function you can run to determine the maximum data size the OS allocates.

Regards,

[davi]

Hi Maclean,
Thanks for this response.
I have a Labview 8.5 license, but haven't upgraded yet.  Any possibility of posting a version of these vis openable in Labview 8.2?
Thanks
- Davi

[sammamishmac]

Hi Maclean,

I have also verified the approximately 1GB upper limit through experimentation. My application can have images as large as 4GB, so I will need to process these in chunks. Will NI be releasing a 64-bit version of LV in the near future?

Thank you,

Ron

[Maclean]

Hi Davi,

Sorry about that! Here are those files in 8.0, let me know if they still don't work.

Regards,

[sammamishmac]

Since the image size seems to be a limitation with the OS (Windows XP), does anyone know if larger images can be processed with Labview running on MacOS or Linux?

Thanks,

Ron

[Maclean]

Hi Ron,

NI-IMAQ and Vision Development Module aren't supported on Linux or OSX, only Windows.

Mac

[sammamishmac]

Hi Mac,

Ok, thanks for the information.

Ron

[SJT]

Photoshop can handle the image in Windows XP.  So its not just the OS. 

[rolfk]

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SJT wrote:
Photoshop can handle the image in Windows XP.  So its not just the OS. 

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The OS is not excusively the reason but mostly. And in this case not because Windows is funky or bad but because 32 bit simply does not give enough resources to handle memory chunks of more than 1GB and also only if the system does not fragment the available memory to much due to background processes/device drivers/system kernel modules.

IMAQ stores pictures in certain formats. Depending on what image type you choose when creating an IMAQ resource, loading an 8 bit image will require IMAQ to convert it to the format you have allocated for the original IMAQ resource which could be a full 32 bit image. That would mean IMAQ is allocating about 4 times as much memory as Photoshop would for such an 8 bit image. Solution would be to make sure you set the type of the image resource when its created to the right one. And quite a lot of IMAQ operations will or optionally can create a copy of the original image to be manipulated.

Also the image types IMAQ supports are optimized for image analysis purposes not for memory consumption. IMAQ's main purpuse after all is image analysis not displaying pretty high color Megapixel images.

So the problem is mostly that in Photoshop the program does everything you may select somewhere as operation on its own, chosing whaterver image format for the intermediate steps it finds best without compromising the image quality to much, while in IMAQ you have a lot more control how it is done, but that also means you have to be more careful what functions, formats, image types and operation sequences you use.

Photoshop as soon as you start to work with layers will certainly start to hickup too on such huge images.

Rolf Kalbermatter

Message Edited by rolfk on 12-14-2007 10:59 AM