Question $5$: Feature Extraction $(20$ pts$)$

Consider the $55$ image I to the right.

A$.(10$ pts$)$ Compute the gradient vector $[$Ix$,$ ly$]$ associated with the circled pixel using the central

finite difference operator $[1/2,0,-\frac{1}{2}.$ Hint: make sure your answer defines a gradient vector

that points $"$up hill" on the intensity surface. Enter answer rounded to $2$ decimal places.

$Ix=$

B$.(10$ pts$)$ Each plot on the left below shows a plot of gradient vector components Ix and ly

computed from a local intensity patch as an intermediate step by the Harris corner detection

algorithm. Identify which intensity patch on the right corresponds to each plot, by writing letter

A$,$ B or C next to the plot.

A

B

C