Re: visually lossless
Cynthia Frazier (mailto:cf12@CORNELL.EDU)
Tue, 30 Aug 1994 08:42:22 -0400
Message-Id: <mailto:199408301246.HAA03733@library.wustl.edu>
Date: Tue, 30 Aug 1994 08:42:22 -0400
From: Cynthia Frazier <mailto:cf12@CORNELL.EDU>
Subject: Re: visually lossless
To: Multiple recipients of list IMAGELIB <mailto:IMAGELIB@ARIZVM1.BITNET>
Thanks Sandeep. I really like this explanation. I'll use it.
>
>The JPEG standard faq explains in the following manner:
>Regular JPEG is "lossy", meaning that the image you get out of decompression
>isn't quite identical to what you originally put in. The algorithm achieves
>much of its compression by exploiting known limitations of the human eye,
>notably the fact that small color details aren't perceived as well as small
>details of light-and-dark. Thus, JPEG is intended for compressing images that
>will be looked at by humans. If you plan to machine-analyze your images, the
>small errors introduced by JPEG may be a problem for you, even if they are
>invisible to the eye. The JPEG standard includes a separate lossless mode,
>but it is not widely used and does not give nearly as much compression as the
>lossy mode.
>
>Sandeep Somaiya
>VTLS INC.,1800 Kraft Drive Blacksburg VA 24060
>W-(703) 231 3605 Fax-(703) 231 3648 Email:mailto:somaiyas@vtls.com
>NeXTMail: mailto:sandeep@next2.vtls.com WWW:http://www.vtls.com
> "Look, Learn, Listen .. Libraries change Lives"