GNOME Bugzilla – Bug 118775
Pre-set aspect ratio in cropping tool
Last modified: 2004-12-22 21:47:04 UTC
I would like to be able to pre-set an aspect ratio and then, as one dragged the mouse in the guestimated direction of the diagonal of the cropping rectangle the mouse pointer would move along the actual diagonal so that the rectangle maintains a constant aspect ratio while being dragged. It would not be necessary to do this with continuous great accuracy so long as at the end of the drag any necessary small correction is made and the rectangle is drawn accurately to the specified aspect ratio and its dimensions displayed in the dialog in the usual way. How would the user set it? perhaps a new item, 'Aspect %', in the menu under the 'px' button. - So minimal change to the present dialog. The on-line help would explain that this meant width/height. Why do I want it? I use this to crop out thumbnail images, which in my case always have fixed dimensions. The resizing that follows the initial cropping is easily automated (mogrify) but to get the aspect ratio right at present means 1)Drag out estimated rectangle, 2) Enter its dimensions into my calculator and divide, 3)Decide whether to increase or decrease width or height and re-iterate. Gimp developer David Neary has suggested a work-around which is to first use the rectangular selection tool which does have the ability to pre-set aspect ratio and then to use the cropping tool in the same image window and click the 'from selection' button. However, apart from being a more roundabout procedure, this has the disadvantage that the selection tool lacks the cropping tool's ability to make incremental adjustments by dragging the corners of the selection rectangle.
I do think that using the "crop from selection" is good enough (one more feature I hadn't noticed in GIMP ;-). But the "Fixed Aspect Ratio" alternative in the rectangular selection tool could be enhanced to "Fixed set of aspect ratios". (The set would be user configurable, of course, but a set of common aspect ratios could be pre-provided.) Very useful if you for instance have several sizes of prints with different aspect ratios available from your on-line photo service. For instance I would most likely want to restrict the aspect ratios to 15:10, 13:10, 10:13 and 10:15 (print sizes (in cm) available here).
We could use the image templates for this instead of creating yet another set of configurable presets.
Hmm, image templates? Argh, I really should catch up on all the nifty new features ;-)
I have looked at gimp 1.3 in connection with this. "Crop from selection" has been made easier. However, this fails to resolve the issue which I described in opening #118775. In summary, being able to adjust the rectangle in both position and size with preview at every such adjustment before activating the crop. This is what I do now with a workaround for aspect ratio in the nature of a pocket calculator. It will remain my method of working unless this enhancement is implemented along the lines I have suggested. On scanning this database I see that my request is not original. Others have asked for the identical thing. looking at recent comments on #118775 I now think my use of the word 'Pre-set' in the short description may have been misleading. 'Setable' would have been better.
Is this a duplicate of #61094? This was suggested to me via email and I don't have the time to check this out at the very moment.
I think this is in essence the same as 61904. I also think the phrase "Constrain ratio" is better than my own "Preset ratio" since the latter has implications of extending the list of configurable preferences which some developers have deplored, and I would agree with them. Its not what 118775 was about. I think it would be good enough if the dialog remembered the last-entered ratio, and I suspect that this would be its behaviour without special coding effort.
*** This bug has been marked as a duplicate of 61094 ***
On second thoughts, since 61094 leaves the UI not specified in any detail whereas 118775 says to use the crop tool with just the change from absolute to ratio in the delaration of the crop parameters, I would suggest that 61094 be considered a duplicate of 118775 rather than vice versa. However, I shall leave the decision to revert status to the developers.