An edge detection filter comprising an array of filter coefficients having an odd number of rows and columns, a first set of zero coefficients extending along a direction traversing the array through a center position to form a first and second side, {TAIL ~ a second set} of positive coefficients extending away from the direction on the first side, and a third set of negative coefficients extending away from the direction on {HEAD ~ the second side} 
An edge detection filter comprising an array of filter coefficients having an odd number of rows and columns , a first set of zero coefficients extending along a direction traversing the array through a center position to form a first and second side , { TAIL ~ a second set } of positive coefficients extending away from the direction on the first side , and a third set of negative coefficients extending away from the direction on { HEAD ~ the second side }
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