Hi --

-------- Original-Nachricht --------
> Datum: Thu, 19 Jun 2008 20:33:43 +0900
> Von: Casimir <pikEISPAMMMseli / welho.com>
> An: ruby-talk / ruby-lang.org
> Betreff: Texture/image similarity with ruby? (computer vision)

> Still no luck so far, still looking. Anyone?

well, what does similarity of two images/textures mean for you ?

Given a (hopefully large) set of images, you could divide it into a 
training set and a set of images to be classified into sets of mutually
similar images. One way to perform both the training and the classification
is using Support Vector Machines. I found these Ruby bindings to a library
providing these by a Google search, haven't used them yet :

http://sourceforge.net/projects/rubysvm/

Most probably, you'll need to read out image information at the pixel level at some point.
Imagemagick is a very powerful library to do this, and Tim Hunter provides
a wonderfully rich Ruby binding to it: RMagick.

Psychologists who have conducted image similarity studies compare many different
measures and filtering methods,e.g., here:

@misc{ karl-perception,
  author = "Dirk Neumann Karl",
  title = "Perception Based Image Retrieval",
  url = "citeseer.ist.psu.edu/635475.html" },

At some point, most of these methods use a (discrete) Fourier transform of some of the
image information and compare the results of the transforms of two images to assess their
similarity.
You could use Ruby-GSL, or Narray with fftw3 to perform that.

Best regards,

Axel 

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