We had a discussion about this some time ago, and a couple of people (John Francis comes to mind as one) suggested that this is not always the case, and that degradation of image quality takes place only in certain circumstances. My recollection is that if a JPEG has not been changed, but just opened for vieweing and then saved, there is no image degradation. I also seem to recall that if only a small area has been changed, such as making an adjustment to one feature in the image, only that portion which has been adjusted suffers. This seems like a good time to clear this up ...
Not all image viewers will "unpack" a JPEG when viewed. Photoshop does (at least recent versions of it) but, for example, Irfan doesn't. Shel > [Original Message] > From: Steve Jolly <[EMAIL PROTECTED]> > Yes, with the important difference that the jpeg packing process > degrades the image quality each time you save it. The advantage of this > is that it makes the file sizes much smaller than a "lossless" > compression format such as compressed TIF. > > S > > Jens Bladt wrote: > > So, a Jpeg is like a zip file, packing itself when saved, unpacking when > > opended?
