From: provine@enel.ucalgary.ca (Joseph Provine) Newsgroups: comp.graphics.algorithms Subject: Re: Hilbert curves vs recursive blocks Date: 2 Apr 1996 02:05:00 GMT In article <315A1E72.4E0@softwarezone.com>, Michael Chock wrote: >Scott Cunningham wrote: >> >> Ok, I found the Hilbert curves in Gems II very interesting and jumped >> right into playing with it. My question is this; What is this useful >> for? I figured it was a great way to optimize graphic compression >> (because it clumps areas together thus optimizing the similarities in >> blocks of color better than a scanline approach) How would this be >> better than just recursively dividing an area into quarters and reading >> it in recursivly smaller blocks; thus: >> >> 1 2 5 6 17 18 21 22 >> >> 3 4 7 8 19 20 23 24 >> >> 9 10 13 14 25 26 29 30 >> >> 11 12 15 16 27 28 31 32 >> >> What am I missing in this? What advantage would it be to have this >> connected by a continuous winding path using a more complex algorithm? >> >> -- >> - Scott Edward Cunningham [scottec@netcom.com] Seattle, Washington, USA - I did some work on compressing (Peano-)Hilbert scanned data. Why go about doing this? - it enhances the correlation between pixels (within a small reasonable neighbourhood) as we exploit correlation in both directions - horizontal and vertical - due to the nature of the curve. There is a preprint at the web-site below and a colleague of mine extended this to an interesting 1-D compression scheme (using fractal geometry). cheers, joseph -- e-mail: provine@enel.ucalgary.ca url: http://www-mddsp.enel.ucalgary.ca/People/provine