6 ms·

Jessica Fridrich Specializes in Problems That Only Seem Impossible to Solve

45 points by ksvs 18y ago

jgrahamc 18y ago
She's the person behind the algorithm in this: http://www.jgc.org/blog/2008/02/tonight-im-going-to-write-myself-aston.html http://www.jgc.org/blog/2008/02/tonight-im-going-to-write-my... And she was incredibly gracious when I emailed her and asked for assistance and she publishes all her research on her web site (http://www.ws.binghamton.edu/fridrich/ http://www.ws.binghamton.edu/fridrich/). The stuff about identifying digital cameras via sensor noise is really interesting.
- ganley 18y ago
  She's done some interesting work... wish the NYT article had focused more on that and less on Rubik's cube.
- _bn 18y ago
  jgrahamc, That is some very impressive stuff. Do you know of any good places to start to get into image processing? (specifically the mathematical tricks (DCT's and such))
  - jgrahamc 18y ago
    Short answer: No. I didn't know anything about image processing at all until I read her paper. It took my quite a while to get to grips with all the terminology and ideas. I actually went through that paper line by line as I built my code and looked up every term I didn't understand on Wikipedia and then used links from there to understand what it was all about. One thing that she needs to be commended on is the clarity of that paper. I was able to follow it and implement her algorithm starting from zero knowledge. She then provided me with the actual images that she had used so that I could verify that my implementation worked. As with anything I'd suggest finding a project that inspires you and the inspiration will be enough motivation to make you learn anything.
  - msg 18y ago
    There's a toolbox for Matlab that encapsulates a lot of digital image processing algorithms. Here's the text we used in my computer vision class, probably the classic in the field: http://www.amazon.com/Digital-Image-Processing-Rafael-Gonzalez/dp/0201180758 http://www.amazon.com/Digital-Image-Processing-Rafael-Gonzal... Learning the specific feature space of digital images is no big deal. You might explore wavelet transformation and different image formats (BMP, JPEG, JPEG2000). Pixel intensity, color, edge detection, high and low pass filtering, connectivity between objects, pattern recognition... there are a lot of topics. And then there are disciplines built on top of image processing, like face detection, watermarking, image retrieval/search, editing/transformation (think Photoshop)... and of course video is another can of worms, adding time-series data. There are strong connections between higher-level image processing and statistical AI and data mining, so you might consider exploring those topics too.
  - lliiffee 18y ago
    I recommend the book "Two-Dimensional Imaging" by Ronald N. Bracewell. I've looked at many signal and image processing books, and I prefer this one by far. Almost all others seem to either shy away from math to the point of absurdity or revel in it to the point of forgetting the practical aspects. Image processing is one of those fields where there is an incredible amount of stuff online, but it is so fragmented, its almost useless to someone who isn't already an expert. A good book builds a consistent set of notation and terminology so that (once you've gotten used to it) you can understand the links and connections between different topics.
Eliezer 18y ago
Good work, Jessica! Now build an AI.
- DaniFong 18y ago
  Eliezer, do you think AI is likely to be built, or emergent? I was thinking the other day that the internet (and the services and people who interact with it) are collectively gaining towards sentience: it has memory (archive.org), recall (search), self-awareness (various part of the internet inspecting the internet is like introspection), even something that you might call emotion, or motivation. It seems like an AI is as likely to emerge by accident, as an entity interacting and viewing it's environment (on the internet) as it is likely to be built from the ground up.
  - beza1e1 18y ago
    Define intelligence first, then we can talk wether or not the internet is an AI.
  - randomwalker 18y ago
    Eliezer has repeatedly expressed his strong view that "emergence" is crap. You may not agree with it, but at least do a cursory search to see if he's already answered your question before you ask him. http://letmegooglethatforyou.com/?q=emergent+site%3Aovercomingbias.com http://letmegooglethatforyou.com/?q=emergent+site%3Aovercomi...
    - JesseAldridge 18y ago
      +1 for the link -2 for being a dick
  - rw 18y ago
    Dani: There are a number of papers discussing the emergence of a "global superbrain". You might be interested in the work of Francis Heylighen and the ECCO group at the VUB (Brussels).
  - markessien 18y ago
david927 18y ago
I thought it was interesting that her name is Jessica -- that's not a Czech name and there's no equivalent. So I looked her up and she was born George (Jiri) Fridrich. She's a transsexual. (Not that there's anything wrong with that. Just interesting.)
- jgrahamc 18y ago
  I'm surprised to see this getting voted up; seems like pure gossip. If anyone on HN wants a detailed list of _my_ sexual activities my contact information is in my profile. Otherwise I'd be happier if you just looked at my code and writing.
  - lief79 18y ago
    I completely agree with you, and yet I can't help but admire that he noticed that random detail and followed up on it. So I'm voting you up and leaving him be.
  - ksvs 18y ago
    Someone changing their gender is not a sexual activity. There was nothing salacious about david927's comment. If anything it is an interesting sociological data point, given the small number of prominent women in math and science.
    - sethg 18y ago
      Sexual reassignment surgery is not a sexual activity, but it is part of someone's medical history, and I think it is in poor taste to gossip about someone's medical history. If Ms. Fridrich had been hospitalized for depression as a teenager, would that also be suitable for discussing on HN?
    - jgrahamc 18y ago
      I agree, but my example was that both sexual activity and changing gender are private activities that don't need to be discussed here.
  - 18y ago
cakeface 18y ago
Don't most of the fastest 'cubers use the petras method (http://lar5.com/cube/ http://lar5.com/cube/) nowdays?
- sharkbrainguy 18y ago
  Petrus, and I don't think so, although it has been a LONG time since I checked. Last I checked most of the fastest were still using fridrich based methods. The most common modifications being, double insertion in the F2L stage (solving two corner-edge pairs with one look) and orienting the last-layer edges while solving the last corner-edge pair of the first two layers, this increases the chances of a "one-look" last layer ( there are only 270 unique positions at that stage ). Some of the fastest are using petrus based methods, but I would say they're strongly outnumbered by fridrich users.

45 points by ksvs 18y ago

She's the person behind the algorithm in this: http://www.jgc.org/blog/2008/02/tonight-im-going-to-write-myself-aston.html http://www.jgc.org/blog/2008/02/tonight-im-going-to-write-my... And she was incredibly gracious when I emailed her and asked for assistance and she publishes all her research on her web site (http://www.ws.binghamton.edu/fridrich/ http://www.ws.binghamton.edu/fridrich/). The stuff about identifying digital cameras via sensor noise is really interesting.

ganley 18y ago
She's done some interesting work... wish the NYT article had focused more on that and less on Rubik's cube.
_bn 18y ago
jgrahamc, That is some very impressive stuff. Do you know of any good places to start to get into image processing? (specifically the mathematical tricks (DCT's and such))
- jgrahamc 18y ago
  Short answer: No. I didn't know anything about image processing at all until I read her paper. It took my quite a while to get to grips with all the terminology and ideas. I actually went through that paper line by line as I built my code and looked up every term I didn't understand on Wikipedia and then used links from there to understand what it was all about. One thing that she needs to be commended on is the clarity of that paper. I was able to follow it and implement her algorithm starting from zero knowledge. She then provided me with the actual images that she had used so that I could verify that my implementation worked. As with anything I'd suggest finding a project that inspires you and the inspiration will be enough motivation to make you learn anything.
- msg 18y ago
  There's a toolbox for Matlab that encapsulates a lot of digital image processing algorithms. Here's the text we used in my computer vision class, probably the classic in the field: http://www.amazon.com/Digital-Image-Processing-Rafael-Gonzalez/dp/0201180758 http://www.amazon.com/Digital-Image-Processing-Rafael-Gonzal... Learning the specific feature space of digital images is no big deal. You might explore wavelet transformation and different image formats (BMP, JPEG, JPEG2000). Pixel intensity, color, edge detection, high and low pass filtering, connectivity between objects, pattern recognition... there are a lot of topics. And then there are disciplines built on top of image processing, like face detection, watermarking, image retrieval/search, editing/transformation (think Photoshop)... and of course video is another can of worms, adding time-series data. There are strong connections between higher-level image processing and statistical AI and data mining, so you might consider exploring those topics too.
- lliiffee 18y ago
  I recommend the book "Two-Dimensional Imaging" by Ronald N. Bracewell. I've looked at many signal and image processing books, and I prefer this one by far. Almost all others seem to either shy away from math to the point of absurdity or revel in it to the point of forgetting the practical aspects. Image processing is one of those fields where there is an incredible amount of stuff online, but it is so fragmented, its almost useless to someone who isn't already an expert. A good book builds a consistent set of notation and terminology so that (once you've gotten used to it) you can understand the links and connections between different topics.

Eliezer 18y ago

Good work, Jessica! Now build an AI.

DaniFong 18y ago
Eliezer, do you think AI is likely to be built, or emergent? I was thinking the other day that the internet (and the services and people who interact with it) are collectively gaining towards sentience: it has memory (archive.org), recall (search), self-awareness (various part of the internet inspecting the internet is like introspection), even something that you might call emotion, or motivation. It seems like an AI is as likely to emerge by accident, as an entity interacting and viewing it's environment (on the internet) as it is likely to be built from the ground up.
- beza1e1 18y ago
  Define intelligence first, then we can talk wether or not the internet is an AI.
- randomwalker 18y ago
  Eliezer has repeatedly expressed his strong view that "emergence" is crap. You may not agree with it, but at least do a cursory search to see if he's already answered your question before you ask him. http://letmegooglethatforyou.com/?q=emergent+site%3Aovercomingbias.com http://letmegooglethatforyou.com/?q=emergent+site%3Aovercomi...
  - JesseAldridge 18y ago
    +1 for the link -2 for being a dick
- rw 18y ago
  Dani: There are a number of papers discussing the emergence of a "global superbrain". You might be interested in the work of Francis Heylighen and the ECCO group at the VUB (Brussels).
- markessien 18y ago

david927 18y ago

I thought it was interesting that her name is Jessica -- that's not a Czech name and there's no equivalent. So I looked her up and she was born George (Jiri) Fridrich. She's a transsexual. (Not that there's anything wrong with that. Just interesting.)

jgrahamc 18y ago
I'm surprised to see this getting voted up; seems like pure gossip. If anyone on HN wants a detailed list of _my_ sexual activities my contact information is in my profile. Otherwise I'd be happier if you just looked at my code and writing.
- lief79 18y ago
  I completely agree with you, and yet I can't help but admire that he noticed that random detail and followed up on it. So I'm voting you up and leaving him be.
- ksvs 18y ago
  Someone changing their gender is not a sexual activity. There was nothing salacious about david927's comment. If anything it is an interesting sociological data point, given the small number of prominent women in math and science.
  - sethg 18y ago
    Sexual reassignment surgery is not a sexual activity, but it is part of someone's medical history, and I think it is in poor taste to gossip about someone's medical history. If Ms. Fridrich had been hospitalized for depression as a teenager, would that also be suitable for discussing on HN?
  - jgrahamc 18y ago
    I agree, but my example was that both sexual activity and changing gender are private activities that don't need to be discussed here.
- 18y ago

cakeface 18y ago

Don't most of the fastest 'cubers use the petras method (http://lar5.com/cube/ http://lar5.com/cube/) nowdays?

sharkbrainguy 18y ago
Petrus, and I don't think so, although it has been a LONG time since I checked. Last I checked most of the fastest were still using fridrich based methods. The most common modifications being, double insertion in the F2L stage (solving two corner-edge pairs with one look) and orienting the last-layer edges while solving the last corner-edge pair of the first two layers, this increases the chances of a "one-look" last layer ( there are only 270 unique positions at that stage ). Some of the fastest are using petrus based methods, but I would say they're strongly outnumbered by fridrich users.