# Corner detection using Chris Harris & Mike Stephens

I am not able to understand the formula,

What is $W$ (window) and intensity in the formula mean,

I found this formula in opencv doc http://docs.opencv.org/trunk/doc/py_tutorials/py_feature2d/py_features_harris/py_features_harris.html

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Read this question about corner detectors: dsp.stackexchange.com/questions/10579/… Other related questions: dsp.stackexchange.com/questions/11497/harris-corner-detection –  visoft Feb 12 at 11:55
–  nikie Feb 12 at 18:12

Harris Corner detector tries to quantify the local intensity changes at all the directions for each pixel. The figure below illustrates the basic idea clearly:

So $I(x+u,y+v)$ indicates the pixel intensities of all the neighborhood pixels around $(x,y)$. The window function is applied for feature localization. For most often used Gaussian function, the choice of sigma value corresponds to different feature width in the image.

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