On Sat, 8 Mar 2003, Jack Aubert wrote: > At 09:46 AM 3/6/2003 -0700, you wrote: > > > > >Do any of you have any format preference (GIF or JPEG) for websites? > >Should we change the graphics to JPEGs? Also, do you think the popups are > >user-friendly? > > The JPEG algorithm for rendering pictures is technically a > "lossy" procedure in that when it compresses the picture it discards some > information.
> If you experiment with turning Gifs into smaller Jpegs you > can judge the results yourself. > > The JPEG procedure falls short, however, when it comes to rendering things > like drawings with sharp straight lines such as org charts and > > So the rule is: Use Jpegs for photos and use Gifs for diagrams. Another issue with JPEG that isn't widely recognized is that repeatedly saving an image as JPEG, while retouching, color balancing, etc., results in loss applied to loss. Eventually, the image quality degrades significantly. It is suggested that you start with a lossless storage system like TIFF, do all your editing in that mode, and only save to JPEG for the final image. With most simple photo editing software, once you do a Save As JPEG, the image in memory is a JPEG, from them on, so first save the edited image as TIFF, Save As JPEG, check that for quality and color, and if you need to edit it further, re-load the TIFF. JPEG also has a feature that allows you to set the quality vs. compression level. You can easily get a 10:1 ratio of file size, but will look closely at the result, and you will see the image problems... Dave 37.28N 121.97W -
