From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <006101c3ed74$042af820$85cf6051@stevesimon> From: "Steve Simon" To: <9fans@cse.psu.edu> References: <89850e23e6bc5a40e7960d1a8b06999e@vitanuova.com> Subject: Re: [9fans] nice hardware for a cpu server (wavelets) MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Date: Sat, 7 Feb 2004 12:15:03 +0000 Topicbox-Message-UUID: d0e6fe60-eacc-11e9-9e20-41e7f4b1d025 Mmm, difficult to explain without a piece of paper. jpag takes DCTs of the image, quantizes the coefficenst and encodes these as the jpeg image (roughly). Wavelet compression (now in Jpeg2000 standard) uses an arbitary waveform (arbitary but fixed and well known) to peform the transform the image. The idea is that the distribution of visually important coefficents is easier to qualify in wavelat space rather than in DCT (which is near 2D frequency) space. Wavelets have many interesting properties image compression is just one application of course. Loads more info at http://www.wavelet.org though you may be amused to know that this points to the same machine as.... plan9.bell-labs.com; they are clever people there. -Steve ----- Original Message ----- From: To: <9fans@cse.psu.edu> Sent: Friday, February 06, 2004 9:08 PM Subject: Re: [9fans] nice hardware for a cpu server > > DjVu on the other hand was a very nice wavelet based image system... > > what are wavelets? > >