GNOME Bugzilla – Bug 108172
Preview while transforming
Last modified: 2004-07-03 01:30:19 UTC
I'm not usre if this feature request is stated clearly in the current wishlists so I'd like to do it. It would be nice during scaling/rotating etc to see not only lots of crossed lines, but instead of that an outline (or something better on faster computer, sort of preview (?)) of scaled image (like in Photoshop). I'd like this feature not because it is in Photoshop, but because it is really usefull. Regards Piotr Legiecki
I don't understand what the outline should look like. Do you have any screenshots that you could attach to this bug report? This looks like an interesting feature, although it will probably be expensive to implement (expensive in terms of CPU cycles as well as developers' time...)
You don't need a screenshot and it's hard to provide them since during processing we can't do simple "print screen". Imagine - you have a photo and want change the layer size or rotate it. Now the funny thing is that GIMP doesn't provide preview which is simple because we only need preview using screen resulution and nearest neighbour scalling. This is a very basic tool and should be implemented a.s.a.p., really. Imagine that you just have scanned image of some buildings taken with normal (ie not shift) lenses. So you have typical perspective with falling buildings. Now it is time to make them look correct using gimp and his perspective correction tools. It would be much easier to see the current image preview being transofrmed than only crossed lines. And it is only one example.
In my opinion, it is a lot more convenient to use the Corrective mode of the Transform tools than to work with a preview. This is the real killer feature of the GIMP's transform tool which makes it stand out against all other applications I have looked at so far.
I agree with Sven. I will leave this bug report open, but as a low-priority item. It would be nice to be able to have direct previews of the area that is transformed, but that would require the GIMP to be able to apply the transformations to the preview at screen resolution. This could only be done after dealing with bug #76096.
I don't see how bug #76096 which talks about improving the display scaling algorithm is related to this report. As already stated in bug #114268, scaled-down versions of individual drawables (as would be needed here) are quite different to what is handled in #76096.
Changes at the request of Dave Neary on the developer mailing list. I am changing many of the bugzilla reports that have not specified a target milestone to Future milestone. Hope that is acceptable.
Optimistically modifying milestone to Future. I'm not sure I see the need for this. I'm tempted to resolve it as INVALID, since I con't see the point. But Future it is :) Dave.
*** Bug 129378 has been marked as a duplicate of this bug. ***
I'd hate to see this one resolved as INVALID. People I know who use both Gimp and PhotoShop cite this as one of the Big Things that put them off Gimp. I don't think the proposed mode should be the default because (as mentioned above) it is likely to be slow on older hardware. But many users with fast machines would find it very attractive.
It won't be closed as INVALID because it's an absolutely valid feature request.
*** Bug 138462 has been marked as a duplicate of this bug. ***
I don't understand why this bug only has a low priority as this lack of preview (during rotating/scaling but also while using filters as said in bug #52374) is the main reason why I still use Photoshop instead of Gimp !
Raising the priority won't make this being implemented a bit earlier. I suggest that if it is important for you, you write a patch and contribute it.
Also there's the Corrective transform mode which makes up for the lack of preview in a lot of cases.
Sorry, it's seems that my comment has been misunderstood. It was just my point of view about what should be improved in Gimp, confirming the Piotr Legiecki's opinion. Personally, I also own Photoshop and I'm really happy with it so I can live without any Gimp improvement. However, I prefer the Gimp Open Source philosophy and I'm ever disappointed each time I try a new version because it's still lacking those few features that could make it THE reference instead of just being a "free Photoshop for nerds" as most people think. That's why this time, I subscribed to bugzilla to check for the next features and was really surprised to see that this so important preview only has a "Low" priority. Once again, it's just my own point of view - but I'm sure that I'm not the only one -, trying to help the gimp community as a simple user because I really think you made a great job with this software.
You misunderstood the Open Source philosophy then. It's about contributions and it's about fun. So if none of the developers feel the need for adding this feature or don't think about it as a tempting challenge that would be fun to implement, then it won't happen. No matter how loud everyone's crying for it. If you want to see this feature in The GIMP, then start to learn your way around the GIMP source code and implement it.
Please so also note that GIMP is not Photoshop nor does it try to be like Photoshop or compete with Photoshop. Whoeever sees it as a "free Photoshop for nerds" has a pretty weird view on the GIMP project.
Hello? GIMP does not compete with Photoshop? Is GIMP and image manupulation programm like Photoshop or not? This bug is really important, and no, corrective transform is not the same. But it is silly to spam bugs. It would be much better if bugzilla.gnome.org had a voting feature like bugzilla.mozilla.org or bugs.kde.org. This way developers could work like they did before and users could express what issues bug them most. There is bug 104739 about voting, I would vote for it if I could.
Created attachment 28631 [details] [review] transform tool options->preview
The perspective preview is not very accurate, but to my knowledge there's not much I can do about it. The preview is more important for rotate/scale/shear anyway, and perspective has corrective mode.
Created attachment 28635 [details] [review] transform tool options->preview silenced a harmless assertion failure that I missed.
That patch is indeed very nice :) However, I don't understand why the option needs to be in GimpDisplayConfig (which ends up in gimprc), gimp_display_shell_get/set_show_transform() can simply oparate on a boolean that's member of GimpDisplayShell. Also, I'd really prefer the preview code to live in gimpdisplayshell-preview.c because gimpdisplayshell-draw.c is large enough already. Apart from that the patch is fine to commit.
Committed to main branch with the changes you suggested: 2004-06-12 Philip Lafleur <plafleur@cvs.gnome.org> * app/display/gimpdisplayshell-callbacks.c: Fixed incorrect logic that caused perfect-but-slow pointer tracking to be used in tools that don't request exact mode. * app/display/Makefile.am: * app/display/gimpdisplayshell-appearance.[ch]: * app/display/gimpdisplayshell-callbacks.c: * app/display/gimpdisplayshell.[ch]: * app/display/gimpdisplayshell-preview.[ch]: added * app/tools/gimpperspectivetool.c: * app/tools/gimprotatetool.c: * app/tools/gimpscaletool.c: * app/tools/gimpsheartool.c: * app/tools/gimptransformoptions.[ch]: * app/tools/gimptransformtool.[ch]: Implemented live transformation previews, available through tool options. Fixes bug #108172.
Very nice. I think however that we need to review the UI and the default settings a little. First of all, the preview should probably be disabled when working in Corrective mode. The default for the traditional transform mode should probably be preview and no grid. Perhaps the preview and grid options can be combined somehow?
Yes, it should definitely be disabled in corrective mode. I believe I also agree with your suggestion of defaults, except possibly for the perspective tool because the preview is misleading. As for combining the grid/preview options, I don't think that's a bad idea - maybe "don't show grid" could be removed from the grid options, and a new combobox could be added, labelled something like "Overlay" and containing options for preview, grid, and none.
Also, Mitch noticed that currently the preview doesn't make use of the selection mask. That needs to be fixed.
Closing as FIXED.
I'd rather see this bug reopened and closed after having all the cleanups: * have the live preview be listed along with the grid settings dropdown (no preview, grid (lines), grid (spacing), pixel preview). Makes little sense to have both preview and the grid lines IMO. * preview selection, not the complete layer * default to preview in regular, to grid lines in corrective mode. and perhaps even try to composite the preview where it belongs in the stack of layers. Dunno if that's doable though. Great stuff though. It's exciting to see this finally getting implemented.
I see "* preview selection, not the complete layer" has been fixed in the meantime
What's missing here is some simple improvements to the transform tool options.
Is there a practical reason to differentiate between density being the number of grid lines and being the spacing between the lines? It makes doing this without creating a cluttered result (two lists, preview type and grid type) or one with exceedingly long menu items (something like "Grid (Density = Number of Lines)") more difficult. I propose a Preview Type dropdown with options for Outline, Grid, and Texture Map, and relabelling "Density" to "Grid Lines", making it refer solely to the number of grid lines.
Created attachment 29097 [details] [review] tentative gui patch
The practical reason is that when doing corrective transforms it can be very helpful to be able to configure the grid precisely (for example when correcting a photo of window with intersections). It's also helpful when scaling something to exactly fit something else. I don't like it being removed actually...
That seems to me to be a pretty unique case and/or something that can be accomplished 99% as well with the number of grid lines. Perhaps you can suggest a good way of fitting it in?
Created attachment 29104 [details] [review] same patch with grid type menu
Created attachment 29168 [details] [review] same patch with grid type menu Fixed to patch against current CVS again.
2004-07-02 Philip Lafleur <plafleur@cvs.gnome.org> * app/tools/gimptransformoptions.[ch]: * app/tools/gimptransformtool.c: * app/tools/tools-enums.[ch]: Replaced "Preview" checkbutton with a combobox with options "Outline", "Grid", "Image", and "Image + Grid". Addresses bug #108172. I think this fixes everything. Closing again.