GNOME Bugzilla – Bug 106730
Initial scale setup is bad for large images
Last modified: 2004-12-22 21:47:04 UTC
Recent revisions of GIMP can handle large (or should I say *real*) images, i.e. the ones that won't fit into physical memory, reasonably well, but only when it is allowed to operate on a small section at a time. This means that the way the image open routines pretty much ruin the day in that they try to set up the scale so that the entire image is visible at once. IMO, images should be disabled at 100% scale initially, especially for large files. A proposed fix will be attached.
Created attachment 14507 [details] Change initial scale to 100% for large images
I also notice that a "thumbnail" of the image is displayed in the GNOME tasklist. Again, probably a *BAD* idea for large images.
Not sure if this report should be treated as a duplicate of bug 103547. The proposed "fix" definitely has too many FIXMEs to be considered for inclusion. But, yes, we should try to find a suitable solution.
I don't understand what is bad about the thumbnail? It is updated from an idle function and we use previews all over the user interface anyway. Of course these previews are shared and not always calculated from the large image.
I haven't really checked the thumnail thing properly, but using an idle function may not help a lot if the operation is going to use a lot of I/O and/or allocate a lot of memory. My experience with other applications is that it's going to slow down the system even though it's supposed to be running silently in the background etc. As for the FIXMEs these should perhaps not be taken to literally; the associated sections of code perhaps need review by the maintainers, but I don't consider them to represent bad or "dangerous" implementations.
BTW, from my point of view[*], the logical way to open an image is with 1:1 zoom and with "Dot for Dot" turned off - and that goes for *all* files (and all users I know ;-)). But: For high-resolution data even that (i.e. "Dot for Dot") give a sufficiently small scale to cause problems. [*] i.e. seen from the world of scanned images.
Not everyone looks at the world from your point of view. Most GIMP users expect to always see the full picture. Well, the default for Dot for Dot can already be configured in the preferences. Perhaps it makes sense to add a new preference option that allows users to choose how images should be scaled initially.
Well, I wouln't know about the current user base, but you'd expect that GIMP would also be useful to users like the ones I'm mostly dealing with, who view the image as a representation of some kind of printed material, and expect in to be displayed in a way that resembles the printed version as closely as possible. Anyhow, I think if there is disagreement about what the correct behaviour, then an option is definitely in its place. Maybe I'll try to add one...
Created attachment 14579 [details] [review] Alternative approach: Add pref to enable/disable zoom-to-fit on open
Not bad although I'm not sure if default-overview is a good name for the prefs setting. Now if the coding style would match our rules (see HACKING) and you could change the default to TRUE (since that's how it used to be), we could actually apply this patch.
I've also experimented a bit with the thumnail generation, and as you suggest, the problems, if any, are related to all previews rather than the just the tasklist icons etc. And there does seem to be a problem with the previews - they increase the image open time quite a bit. With the default setup, I get a long delay after the progress dialog indicates the load is complete, before the image window actually appears, but if I short-cut the preview generation code, it pops up right away.
Well, you could set preview-size=none but this is unrelated to this bug-report.
I also considered calling the pref "default-zoom-to-fit"... As for the default value, you could argue that "FALSE" is the most defensive setting (as enabling the option turns on functionality that is potentially very time consuming, may hang the system etc.), and thus the correct one, but I guess I might just change the global config files for my installation...
Regarding the previews and the problems created by large images, I have just submitted a new bug report: see bug #106960.
Created attachment 14604 [details] [review] "zoom-to-fit" pref, take 2
2003-02-25 Sven Neumann <sven@gimp.org> * app/config/gimpdisplayconfig.[ch] * app/config/gimprc-blurbs.h * app/display/gimpdisplayshell.c * app/gui/preferences-dialog.c: applied a modified version of a patch from Toralf Lund <toralf@kscanners.no> that adds a new preferences option to choose the inital zoom ratio. Fixes bug #106730 and in my opinion also #103547.
*** Bug 108935 has been marked as a duplicate of this bug. ***