This function plots coresponding points between two images. It is pretty useful (at least for me) in visual debugging for matching feature points, such as SURF or SIFT features.
h = match_plot(img1,img2,points1,points2)
points1 = [x1 y1; x2 y2; ...] = coresponding points in img1
points2 = [x1 y1; x2 y2; ...] = coresponding points in img2
origin is the top left of the image
x axis pointing right, y axis pointing down.
points2 has to be the same size as points1.
if two images have different size, the smaller one is rescaled.
coresponding lines are plot in different colors, from red to blue in
returns the figure handle object h.