dneary@free.fr (2004-04-22 at 2142.26 +0200):

On PotatoShop (forced to used at gunpoint), there are no problems editing this image or other large images.

Photoshop handles large images better than GIMP. That's a known fact and it's not trivial to improve.

How, exactly? I've heard this too, but I have no clear idea how they do so - do they have a similar caching system, and just make better decisions about what to cache and when? Or do they use OS specific features to reduce read times for caching operations? Or perhaps something completely different?

One thing that GIMP could do is top to bottom composing, if the blend modes allow it. It will mean that calculations will never be worthless and that only contributing tiles will have to be accessed. That should speed up things and reduce memory usage in some cases.

GSR

Photoshop handles large images better than GIMP. That's a known fact and it's not trivial to improve.

Ummm, well that known fact isn't completely true. In actual fact, Photoshop will *not* handle many of the large images that we work with at all, whereas the GIMP will do so with no problem. Photoshop has an inherent 32K maximum pixel limitation in both height and width that the GIMP is not saddled with.

Photoshop may process reasonably large images somewhat faster than the GIMP can, but the GIMP can handle huge images that make even the latest versions of Photoshop roll over and croak.

s/KAM

Kevin Myers (WHMyers@cableone.net) wrote:

Photoshop handles large images better than GIMP. That's a known fact and it's not trivial to improve.

Ummm, well that known fact isn't completely true. In actual fact, Photoshop will *not* handle many of the large images that we work with at all, whereas the GIMP will do so with no problem.

Will the wonders never cease?

Thanks, it is great to hear that :-)

Bye, Simon

Hi,

David Neary writes:

Photoshop handles large images better than GIMP. That's a known fact and it's not trivial to improve.

How, exactly? I've heard this too, but I have no clear idea how they do so - do they have a similar caching system, and just make better decisions about what to cache and when? Or do they use OS specific features to reduce read times for caching operations?

AFAIK they don't load the full image into memory. If you open a large image, only the preview is loaded and if you zoom in, then only the necessary parts are pulled into memory. Of course this doesn't work with all file formats.

Sven

On 23 Apr 2004, Sven Neumann wrote:

Hi,

David Neary writes:

Photoshop handles large images better than GIMP. That's a known fact and it's not trivial to improve.

How, exactly?

AFAIK they don't load the full image into memory. If you open a large image, only the preview is loaded and if you zoom in, then only the necessary parts are pulled into memory. Of course this doesn't work with all file formats.

There are already bugzilla entries about this -- most prominantly #107246. I have a feeling to do this right it would have to be a fairly sophisticated GEGL node. Why aren't I on gegl-developer again? :)

Rockwalrus