Abstract: A system constructs a block direction for a first print and compares the block direction image to a direction image for a second print to determine a similarity measure between the first and second prints. Constructing the block direction image includes: receiving a plurality of minutiae for the first print, with each minutia being associated with a location, a direction and a quality; and for each of the plurality of minutiae, assigning within the block direction image a plurality of corresponding neighboring blocks, and for each neighboring block determining a density rate that is a function of a distance from the neighboring block to the location of the corresponding neighboring minutiae, a block direction that is a function of the density rate and the direction of the corresponding neighboring minutiae, and a block quality that is a function of the density rate and the quality of the corresponding neighboring minutiae.