Am 18.11.2015 um 10:25 schrieb Stéphane Gourichon: > Hi Christian, > > I have considered (though not implemented) a similar case. > > In my case, the correct thing to do would be to automatically enlarge > the cropping area and recrop from the original file. > > What I would do is first just like you do : use darktable to export a > JPEG. But I would consider that JPEG a "work print", and keep the > original file and XMP at hand. > > Separately, a script would : > * take as argument the original file and a new aspect ratio > * parse the "work print" XMP > * figure out the new crop area > * generate a temporary XMP > * call darktable-cli to generate the needed JPEG. > > That JPEG would have your aspect ratio.
Interesting. I wonder what the purpose/application of this workflow is. Is there any benefit over exporting full-size with crop information, given that the crop metadata is widely used by the tools? > But I never implemented it and haven't actually checked how the crop > information is stored in the XMP, if it's easy to parse and generate. > > Moreover, just enlarging the area to the requested aspect ratio might > not always be what you need, and might not always be possible (for some > aspect ratio, the enlarged area would in some case go outside the actual > initial photo which might be a problem in your case). Of course, but for the shots I intend to use for these purposes I usually shoot a bit wider so that there is something to crop. Of course I often shift the images a bit as well. Getting the crop and composition 100% right in camera is for real art where every picture is displayed separately, not for what I am doing ;-) Whenever the image itself is not the final product but you are shooting for a special purpose/further processing, it is always good to keep that purpose in mind while shooting. For calendars/photo books it may be to shoot a bit wider (or for whatever may need some bleed in print as well), for magazine covers you need space for text etc. etc. > I'm curious about any other solution. Me too :-) > My two cents. :-) > > > On 18/11/2015 09:55, Christian Mandel wrote: >> Hi, >> >> is it possible to write crop metadata (see >> http://photo.stackexchange.com/questions/43893/how-to-store-tilt-rotation-and-crop-information-in-metadata, >> xmp parameters for crop values) instead of actually performing the crop? >> I guess it is not a standard feature (at least I did not find it) but >> maybe it is possible with lua? >> >> The background: I do a lot of design work with photographs from dt >> (calendars, photo books, etc.). Therefore, the photographs have to fit >> within given frames. When I crop in dt (e.g. in 2:3 format) and use it >> in a 4:5 template, I have to crop again, which is often not possible due >> to losing important image parts. For these situations it would be better >> to be able to "add" some picture at the other edges. Therefore, I have >> to go back into darktable, crop different, export again and reuse the >> image, which is cumbersome. >> >> Not cropping in dt is cumbersome as well since I want the exported image >> to appear as intended and the changes to make the image fit are only >> minor corrections, not changing the message of the image. Furthermore I >> use the images in multiple “products”, e.g. calendar and photo book. >> That means, I have to manually keep track of the initial intended crop >> and reproduce it for every purpose. On the other hand, initially doing >> multiple crops in dt would spam my lighttable and my export directories. >> Therefore I think writing crop to image metadata and exporting full size >> images sounds like a perfect idea. >> >> I guess the complementary functionality is not implemented in the tools >> that I use down the chain (inkscape, scribus and image viewers), but I >> have to start somewhere, and from the link above it does not sound too >> hard to do it. >> >> Any hints welcome :-) >> >> Thanks & best regards >> >> Chris >> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Darktable-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/darktable-users > > ------------------------------------------------------------------------------ _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
