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QuestionDrop Down select Pin
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QuestionPlease help with image feature extraction code! Pin
supernorb20-Mar-12 2:11
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supernorb21-Mar-12 2:40
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Alan Balkany21-Mar-12 4:43
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BupeChombaDerrick2-Apr-12 13:02
BupeChombaDerrick2-Apr-12 13:02 
I will assume color processing is what you want... i can advise that you start with color opponent process as occurs in the retinal ganglion cells see http://en.wikipedia.org/wiki/Opponent_process[^]
opponent process results in Red vs Green, Blue vs Yellow and Black vs White channels, if you are wondering why go through this process?

Well color sensor response overlaps (even the photo receptors in animals & humans) , and it is biologically proven to work.Cool | :cool:

but only Red vs Green and Blue vs Yellow are what is needed for color processing. you can obtain a two dimensional vector at any position (one sample per channel) normalize the vector to unity magnitude and store it with the associated color (in an indexing structure like the Kd tree see http://en.wikipedia.org/wiki/Kd_tree[^]) as a prototype. So get such descriptors for all colors. then at run time repeat the whole process except that you run the indexing structure and label each pixel with a given color based on it's closest prototype in the indexing structure. Then you can do some statistics such as create a histogram to count the frequency of occurrence of each color and normalize the histogram, and that will be a descriptor vector for an image hence the resulting color descriptor can be used to retrieve images or compute their similarity score.

or and 1 week, where have you been? Laugh | :laugh:

And as for feature extraction, there are low,intermediate and high level features, most of computer vision uses either low or intermediate level features there are so many algorithms for that such as SIFT (Scale Invariant Feature Transform) see http://en.wikipedia.org/wiki/Scale-invariant_feature_transform[^] and http://www.cs.ubc.ca/~lowe/papers/ijcv04.pdf[^]
Questiontheory needed for a described algorithm Pin
liquid_15-Mar-12 22:07
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Bernhard Hiller16-Mar-12 1:10
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Bernhard Hiller18-Mar-12 21:31
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Questionaudio watermarking Pin
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QuestionSuper2xSal, SuperEagle, hq2x algorithms Pin
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QuestionConvert between image file formats??? Pin
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