Re: feature extraction on selected salient point

Did you see this?

http://en.wikipedia.org/wiki/Local_binary_patterns

"Local Binary Patterns (LBP) is a type of feature used for
classification in computer vision. LBP was first described in 1994.[1]
[2] It has since been found to be a powerful feature for texture
classification; it has further been determined that when LBP is
combined with the Histogram of oriented gradients (HOG) classifier, it
yields the best classifier of humans (i.e. person vs. non-person)
among the classifiers usually considered in academic literature[3].
[edit] Concept

The LBP feature vector, in its simplest form, is created in the
following manner:

* Divide the examined window to cells (e.g. 16x16 pixels for each
cell).
* For each pixel in a cell, compare the pixel to each of its 8
neighbors (on its left-top, left-middle, left-bottom, right-top,
etc.). Follow the pixels along a circle, i.e. clockwise or counter-
clockwise.
* Where the center pixel's value is greater than the neighbor,
write "1". Otherwise, write "0". This gives an 8-digit binary number
(which is usually converted to decimal for convenience).
* Compute the histogram, over the cell, of the frequency of each
"number" occurring (i.e., each combination of which pixels are smaller
and which are greater than the center).
* Optionally normalize the histogram.
* Concatenate normalized histograms of all cells. This gives the
feature vector for the window.

The feature vector now can be processed using the Support vector
machine or some other machine-learning algorithm, to produce a
classifier."

End of quote



It has a link to some source code.
.

Relevant Pages

  • Re: Help on choosing a valid pattern: composite or not?
    ... I have started with a more general case: a classifier. ... Typically a node deals with one feature. ... removing should leave the classifier's network operating. ... > That's what made me concerned about the "Composite Pattern". ...
    (comp.object)
  • Re: Classification problem question
    ... unknown image sample as belonging to one of several known classes. ... classifier and see how many mis- or un-classiffied pixels you get according ...
    (sci.image.processing)
  • Re: Minimum distance classifier
    ... unclassified pixels. ... You assign an area to a training class using ... How the classifier assigns pixels depends on ... unclassified pixels are assigned to the ...
    (sci.image.processing)
  • How to design a weak classifier to classify histogram
    ... I am designing a boosting classifier to classify face ... image, the feature of image is the histogram of gray value, but now I ...
    (sci.image.processing)
  • How to design a weak classifier to classify histogram
    ... I am designing a boosting classifier to classify face ... image, the feature of image is the histogram of gray value, but now I ...
    (comp.graphics.algorithms)