On Tue, 10 Jul 2007 00:46:44 +0200, peter sikking <peter@xxxxxxxxxxxx> wrote:> There is also a real benefit in opening a jpeg and then saving> the result in another (GIMP) file. We see from the explanations in this> thread that opening a jpeg and then saving it again means a loss of> information. So overwriting an original is a loss. Working on a> full-fidelity copy version is preferred. Note that in the workflow that I described, I never mentionedoverwriting the original. On the contrary, I said that the finalJPEG file would be saved under another name. > The early part of this thread is full of misunderstanding at which> point working with jpeg incurs quality loss. I say it is because of> the "you can work in jpeg" myth. I am still confused that you talk> about saving intermediate results while working on a jpeg. Either> each save reduces quality (implicit save and reload, ouch) or there> is a penalty for closing the file and reopening it, because you> lost the full-fidelity internal (GIMP) representation, ouch. I am not sure about what others had in mind in this thread, but II was mostly focusing on corrections to the source photos such ascorrecting the exposure or color balance and making other minoredits with the clone tool, etc.. These steps can be performed ina single session without having to save any full-fidelity internalrepresentation. When I mentioned saving intermediate results, Imeant saving copies of the image that you are currently working on,if you want to check how the final output will look like (includinglosses due to compression). If you intend to work further on the image or to re-use some partsof it in a collage or in a more complex work, then it certainlymakes sense to save the XCF version (or any other lossless format).The same applies if you work more than a few minutes on the imageand it would cost too much to re-do these changes from the originalin case you decide some weeks later that you need to apply morechanges to the image. But for the simple workflow that I described (which is or wasrather common for me), in which simple corrections have to beapplied to a large number of images without intending to work onthem further, then it makes sense to have JPEG as input and asoutput without wasting time or space with intermediate formats. > So I see real benefits for a high-end image manipulation program> that lossy formats are pushed out to the very beginning and very> end of the workflow. That the working copy of the file is GIMP format,> in full fidelity, any GIMP operation naturally possible, and with> no penalty for opening and closing the file. I am not disputing that. We should encourage users to use thelossless XCF format for all things that may need to be editedlater or re-used in other images. As long as this can be donewithout breaking common workflows, then it's fine. I don't mind if the simple load-edit-save cycle for JPEG imagesproduces a warning the first time I do that, telling me thatsaving in JPEG will result in a quality loss and recommendingXCF for saving any work-in-progress. But would mind getting this warning every time or being forcedto use a different menu option than the normal Save for thesecond and subsequent attempts at saving the image. This ishow I interpreted your initial reaction. If I misunderstoodwhat you meant and you did not intend to break the flow, thenI am sorry for the misunderstanding and we can forget about itbecause there is really no issue. -Raphaël P.S.: If this issue is cleared and we ignore the arguments for the sake of argumenting (my previous message), then I think that I have a solution for the original issue mentioned in this thread: this is very close to the patch proposed by Tor and it also supports JPEG files that were not created by libjpeg. More about that later, when my code is ready._______________________________________________Gimp-developer mailing listGimp-developer@xxxxxxxxxxxxxxxxxxxxxxxxxxx://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer
