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matlabsimilarityimage-recognition

how to measure the cosine similarity between 2 images

I have a population matrix of 5 images with 49 extracted salience features. I want to calculate the cosine similarity in Matlab between a test image with the same extracted features 49.

Solution

  • 1) Transform your images of size M lines X N columns in a vector M*N lines. Keep one image in a vector u and the other image in a vector v.

    2) Evaluate: cosTheta = dot(u,v)/(norm(u)*norm(v)); [As far as I know there is no function in matlab that does that]

    Usually people evaluate similarities among images using the projections of them on the eigenfaces. So, before doing that, people usually evaluate the eigenfaces.