Message-Id: <mailto:199607121413.JAA17494@library.wustl.edu> Date: Fri, 12 Jul 1996 09:11:17 -0500 From: Alan Newman <mailto:anewman@ARTIC.EDU> Subject: Re: Lossless JPEG? To: Multiple recipients of list IMAGELIB
>Is it possible to have a lossless JPEG file? If so, what would the
>compression be vs. a typical original with no compression? I have only
>heard/read of lossy JPEG, since this is how one obtains better file sizes
>for distribution purposes. A recent article I came across mentioned
>"lossless JPEG", however, and I'd like to check. Thanks in advance!
>
>Pamela
>
>Pamela R. Mason
>Chief, Electronic Information Program
>NIST, Office of Information Services
>Admin. E-106
>Gaithersburg, MD 20899
>Ph: (301) 975-4465
>Fax:(301) 869-8071
>E-mail: mailto:pmason@enh.nist.gov
Pamela,
Lossless image files are those typically done with compressors such as Stuff-It, Compact-Pro and DiskDoubler. They usually save about 50% of file space. Also TIFF and PICT formats have built-in compression that is lossless.
JPEG files can be saved at near lossless quality, but are never truly lossless.
Thanks, Alan
-------------------------------------------------------------------- Alan Newman, Executive Director tel. 312 443-7247 Imaging & Technical Services fax. 312 443-0849 The Art Institute of Chicago email:mailto:anewman@artic.edu 111 S. Michigan Avenue Chicago, IL 60603