sdm7g@Virginia.EDU (Steven D. Majewski) (06/25/91)
I will not defend this quote.I merely offer it up for discussion. ( I can't defend it: I don't know anything about wavelets, although I will immediately look up one of the references he mentions: Daugman, John, ENTROPY REDUCTION AND DECORRELATION IN VISUAL CODING BY ORIENTED NEURAL RECEPTIVE FIELDS, in IEEE Transactions on Biomedical Engineeringm Vol 36, no 1, Jan '91 ) No offense intended to all of the people so diligently working on the PD JPEG implementation, from whom I have learned most of what I know about JPEG compression. ------------------------------------------------------------------ ______________________________________________________________________ from Don Lancaster's HARDWARE HACKER column in the JULY '91 RADIO ELECTRONICS magazine: _______________________________________________________________________ "At any rate, an awful lot of people have spent an awful lot of time and money to make the DCT a major new video compression standard. Even PostScript Level II now has build-in DCT filters, and dozens of firms are offering or about to offer DCT compression solution." "The only little problem here is that the wavelet transforms pass the DCT like it was sitting up on blocks. It appears that anything that the DCT can handle, wavelets can do faster, cheaper, better, and with far fewer objectionable artifacts." "In particular, there are background "tiling" effetcs using the DCT, but none using wavelets. Your wavelet transform computations are quite simple, ane much easier to realize in standard or near-standard hardware. Wavelets are also good at building up the "big limps" first, followed by finer detail. That gets important in a rapidly changing video scene." "So, I guess we are going to shortly see the answer to the question "What happens when a bunch of people spend lots of time and effort creating a new standard that is clearly and ludicrously obsolete before the ink on the final version is dry?" stay tuned on this one." ( * DCT = Direct Cosine Transform; one step of the JPEG compression scheme. ) ======== "If you have a hammer, find a nail" - George Bush,'91 ========= Steven D. Majewski University of Virginia Physiology Dept. sdm7g@Virginia.EDU Box 449 Health Sciences Center Voice: (804)-982-0831 1600 Jefferson Park Avenue FAX: (804)-982-1616 Charlottesville, VA 22908