Tag: algorithm

Human Computation

For example, you might ask Mozes Mob (as I recently did) where the best car washes are in San Diego. Local subscribers will ping back almost instantly, via IM or SMS, with answers to your question.

Why do people do it? Call it an example of human computation. People are better searchers than computers are, especially for local services, and they want to share that knowledge. It works, and it’s an insanely interesting app.

using human computation and SMS to improve local search
2007-03-24:

I do this primarily for the money, but I also view it as a form of therapy to get me used to working again> The experience has gotten me thinking about pursuing a library science degree.

2007-09-22:

No one but a utopian would have predicted how readily people will work for free.

in their treatment of human computation. i also like the snarky coining of eHarmony spouse.

Comparametrics

image stitching and correction algorithms

A particular class of functional equations, called comparametric equations, is introduced as a basis for quantigraphic image processing. Comparametric equations are fundamental to the analysis and processing of multiple images differing only in exposure. The well–known “gamma correction” of an image is presented as a simple example of a comparametric equation, for which it is shown that the underlying quantigraphic function does not pass through the origin.

For this reason it is argued that exposure adjustment by gamma correction is inherently flawed, and alternatives are provided. These alternatives, when applied to a plurality of images that differ only in exposure, give rise to a new kind of processing in the “amplitude domain” (as opposed to the time domain or the frequency domain).

Algorithmic beauty

  • Judy rarely compromises speed/space performance for simplicity (Judy will never be called simple except at the API).
  • Judy is designed to avoid cache-line fills wherever possible. (This is the main design criteria for Judy.)

it is rare that you get in touch with basic algorithms as a software engineer these days. lo and behold, there is still scope for fundamental improvements to very basic algorithms, such as trees. ah, such beauty. if i only had the mental staying power to fully appreciate it 🙂