.jpeg compression is somewhat like "zipping" a text file, if there are 100 spaces in a row in the text file then the zipper stores the number 100 and the ascii character for "space" so it can reconstruct later. The difference in .jpeg compression is it is a "lossy" compression, it guesses how many *similar* pixels it can make the same color/intensity without the human eye noticing. The higher the compression ratio the worse these guesses are. Try saving .jpegs at very low quality (high compression) and you will see what I mean very easily. Heres one from last night at 75% and 0% quality settings:
http://www.donsauction.com/PDML/likecats.htm Don > -----Original Message----- > From: Jens Bladt [mailto:[EMAIL PROTECTED] > Sent: Saturday, November 13, 2004 5:52 AM > To: [EMAIL PROTECTED] > Subject: RE: Reducing File Size with Photoshop > > > > I guess I don't understand what a jpeg compression really does! > But you are right - I saved a jpeg file as a tif and then it kept the 18MB > size, showing this in the Path Finder. > Jens Bladt > > mailto:[EMAIL PROTECTED] > http://hjem.get2net.dk/bladt > > >
