Archived posting to the Leica Users Group, 2006/02/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]So why it is not compressed - smaller, that is - the new file can even be larger than the original. I know that no new information cannot be created but does not compressing make files smaller - that is the very idea. All the best! Raimo K Personal photography homepage at: http://www.uusikaupunki.fi/~raikorho ----- Original Message ----- From: "Eric" <ericm@pobox.com> To: "Leica Users Group" <lug@leica-users.org> Sent: Saturday, February 25, 2006 2:25 PM Subject: Re: [Leica] Daily Dose of Spring XI > Raimo: > >>If you select to save JPGs using original quality it will not be >>compressed again - at least the programs I use do it this way. > > I would be careful. All JPG compression is lossy. That is, when you save > the jpeg file, it throws away some information. So the next time when you > open the file, it doesn't have 100%. Which is fine for saving once and > viewing. But if you save again, then you're tossing out more information. > Viewing jpegs is fine. And there are some programs that can rotate jpegs > without losing information. But if you save again, you will lose > information. If you save using the original quality, I'm guessing that > means use the same level of compression that was first used. If you > change > an image and then save the jpeg again, it *will* be compressed again. > That's the way jpeg works. > > > > -- > Eric > http://canid.com/ > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information