Vlasta wrote on 2009-02-02 10:53:04 UTC: >while I have heard about possible plans about how to do lossless resizing >from one of the JPEG guys, it would require extension of the standard and it >would only be able to resize to 1/8, 2/8, 3/8, ... of the original size. > >It does not really make much sense, resizing is destructive by nature and you >usually resize picture to make the file physically smaller, which would not be >possible if it were lossless. > >BTW, I am author of a Windows application for lossless rotation cropping, >canvas extension and retouching called RealWorld Photos.
Not an extension of the standard, but a different standard. I was reading jpeg2000 wikipedia when I posted the question of lossless resizing JPEG. It has the following about "multiple resolution representation": 'JPEG 2000 decomposes the image into a multiple resolution representation in the course of its compression process. This representation can be put to use for other image presentation purposes beyond compression as such.' So I think, if an image viewer can take advantage of this feature and read only some parts of a file to render a reduced-resolution picture, the higher resolution representation then can be stripped off to resize a picture without fully decompress it first. Back at the time I post the question, I was naive and intuitively think jpeg200 is just a flavour of JPEG, and must be a commonly used flavour, like HTML4 is a flavour of HTML and most commonly used one. Now I know they are incompatible standards. Since jpeg2000 failed to get much practical use, whether or not it can resize losslessly became a moot point. -- zhangweiwu (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
