On 13 Jun 2005 at 17:17, Shel Belinkoff wrote: > Sometimes the result is subtle, other time not. I did this recently and > noticed that the information data for the JPEG showed fewer colors each > time it was saved. I also created a highly out of gamut JPEG in Photoshop, > and > the out of gamut information was set up to show in bright red. Each time i > saved the file the amount of red diminished. > > Someone's probably going to say that the "test" is bullshit and doesn't > conform to scientific principles. I don't care - I'm just not going to > continue opening and saving JPEGs.
I have no doubt about the validity of your observations however if a jpg image hasn't been transformed in any way it should be saved without loss of colour/detail. A transformation could also take the form of rendering an image to an alternate colour space. In the context of the initial discussion though I think you would find that there is generally very little advantage in saving a digitally acquired and in- camera processed images in TIFF format over low compression JPG. If post processing is likely to entail repeated saving/opening cycles the files would be saved in a loss-less format such as TIFF. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
