Wavelets (1994) [pdf]

#1

Post by rubenbe » Tue, Aug 13, 2019, 7:20 PM UTC

Wavelets (1994) [pdf]
cybertester.com

Re: Wavelets (1994) [pdf]

#2

Post by high_pathetic » Wed, Aug 14, 2019, 9:54 PM UTC

My thesis defense was about wavelets and it was in 1995! Had to implement my own FTT and rendered 3D charts in Excel...

Re: Wavelets (1994) [pdf]

#3

Post by patentatt » Wed, Aug 14, 2019, 10:06 PM UTC

Wavelets were supposed to be a big thing like 15-20 years ago ... what happened? Do any mainstream modern codecs use wavelets? I’m not aware of any

Edit: looks like the Dirac video codec is based on wavelets. Good to know all of that research wasn’t for nothing!

Re: Wavelets (1994) [pdf]

#4

Post by gsmethells » Wed, Aug 14, 2019, 10:18 PM UTC

JPEG2000 uses Wavelets https://en.wikipedia.org/wiki/JPEG_2000

Re: Wavelets (1994) [pdf]

#5

Post by misiti3780 » Wed, Aug 14, 2019, 10:43 PM UTC

i wrote my master thesis on wavelets! a few years back they morphed into shearlets and contourlets.

https://en.wikipedia.org/wiki/Contourlet

https://en.wikipedia.org/wiki/Shearlet

Re: Wavelets (1994) [pdf]

#6

Post by ncmncm » Wed, Aug 14, 2019, 10:49 PM UTC

Who gets taught wavelets now?

Are they supposed to displace Fourier decompositions, or did that fizzle?

Re: Wavelets (1994) [pdf]

#7

Post by AceJohnny2 » Wed, Aug 14, 2019, 11:07 PM UTC

patentatt wrote: post #3

Wavelets were supposed to be a big thing like 15-20 years ago ... what happened? Do any mainstream modern codecs use wavelets? I’m not aware of any Edit: looks like the Dirac video codec is based on wavelets. Good to know all of that research wasn’t for nothing!

I'm partly speaking out of my ass from second-hand experience 10 years ago but...

Wavelet-based codecs turned out to be much harder to implement in hardware that fourier-transform-based ones (for which we have FFT!). That disincentivized development, which is why you only have Dirac (an open-source, non-HW-industry-backed effort) that uses it.

Re: Wavelets (1994) [pdf]

#8

Post by gdy » Wed, Aug 14, 2019, 11:42 PM UTC

Implemented FDWT as part of a coursework project many many years ago when it was hip :)

Re: Wavelets (1994) [pdf]

#9

Post by lp251 » Wed, Aug 14, 2019, 11:47 PM UTC

patentatt wrote: post #3

Wavelets were supposed to be a big thing like 15-20 years ago ... what happened? Do any mainstream modern codecs use wavelets? I’m not aware of any Edit: looks like the Dirac video codec is based on wavelets. Good to know all of that research wasn’t for nothing!

JPEG2000, I believe.

Re: Wavelets (1994) [pdf]

#10

Post by jstewartmobile » Thu, Aug 15, 2019, 12:10 AM UTC

Gilbert Strang is a delightful writer.

"What do you say to a thesis student you don't remember? In that position I suggest something very short: 'Tell me more.' The most amazing part was his thesis topic. 'I am designing the filter bank for MIT's entry in the HDTV competition.' Some days you can't lose, even if you deserve to."