[Scribus] Can't place some JPEG images

[Craig Ringer]

Cedric Sagne wrote:
> Andreas,
> 
> with 512 MB of RAM, loading 105 MB for an image should be fine...

Absolutely.

> I admit that Photoshop on Windows has difficulties doing more than that.
> In fact the whole thing about DTP (or so i thought) is using large files 
> and managing them efficiently, abstracting them along the way.

It shouldn't have any issues. In fact, Photoshop should be able to work 
with images larger than physical RAM because of its use of a tile cache, 
scratch disk, etc. Photoshop essentially has its own virtual memory 
system optimised for image handling. I've certainly had no problems on 
the XP boxes or the OS X machine here, even when working with very large 
images. It's not fast of course - because it's having to use very slow 
disk storage to compensate for insufficient main memory - but it works.

> I thought Scribus was "linking" to the files and using for memory 
> purposes shrunk versions of them in order to optimise memory, which is 
> why the workflow implies storing the images in a separate folder and 
> assembling the finished product...

It does. However, to produce those shrunken images when the doc is 
loaded, and at certain other points along the way (such as when 
resampling the final image for inclusion in PDF output) Scribus must 
load and process the whole image.

That's not to say there's no room for improvement. Far from it. Images 
can be loaded more quickly and efficiently (witness Xara), resampled 
more efficiently, and so on. It's also possible to be smarter about when 
and how they're loaded.

One of the things that'd be nice would be to cache thumbnails of the 
images in the .sla or in a cache directory, at least optionally, and key 
them to the source image's mtime and size. That way we could avoid 
loading the source image if it hadn't changed since we generated
the preview version. That would help a LOT with doc loading performance 
when large images are in use. QuarkXPress has been doing this for a long 
time, along with providing the ability to print using those preview 
quality images for a rough layout preview without the time cost of 
loading all those big images.

--
Craig Ringer