Posted by
Michael Schmid on
Oct 31, 2008; 4:26pm
URL: http://imagej.273.s1.nabble.com/using-very-large-images-tp3694602p3694603.html
Hi Severino,
it depends very much on the type of image (8 bit, 16 bit, 32 bit
grayscale or 24-bit/pixel RGB) and the operation you want to do.
Most simple operations (3x3 filter operations like smooth, sharpen,
edge detection) need at least twice the memory needed to store an
image; for the original and the processed version.
The functions in Process>Filters convert the image to float (32bit/
image) for processing, so you need twice the original image size + 4
bit/pixel.
Other functions can need even more. I don't know for TurboReg.
ImageJ supports large RAM sizes on some systems, see, e.g. the FAQ
"How do I increase the memory in ImageJ?" on the documentation wiki
http://imagejdocu.tudor.lu/Hope this helps a bit.
Michael
________________________________________________________________
On 31 Oct 2008, at 16:37, Severino wrote:
> I am using some functions of ImageJ for processing earth
> observation images. ImageJ is so easy to use and so efficient, that
> it makes an extremely useful tool, even if it has not been
> developed for remote sensing images and it does not support some
> functions needed in this area.
> As the remote sensing images (from satellites) are extremely large
> (6000 by 6000 pixels is not one of the largest) I would like to
> know how I can predict which is the largest image size I can
> process with ImageJ in my computer. Is there any manual where to
> find how I could predict it? can it be done at all?
> I use frequently TurboReg and I think I could circumvent the size
> limitation just dividing the large image in smaller ones,
> performing registration and then merging the registered images
> again. Has somebody already written some macro script for it? This
> would be an acceptable solution.
> Thank you
> Severino