A computer based image processing system uses an extraction process to extract one or more features from a target fingerprint image. The feature extraction process identifies one or more of the following features of the fingerprint: orthogonal image contrast, parallel image contrast, feature confidence, distance between two minutia, neighbor information, angle-distance between two minutia, angle-distance neighbor information, minutiae density, ridge length, ridge density, and wiggle factor. A pruner process, executing on the computer system, determines if one or more of the features meet any one or more of a set of pruning criteria, and that deletes the minutiae if the pruning criteria is met. The pruning process is based on (i) locations and image contrast, (ii) the distances, orientations of minutiae and (iii) spatial distributions of minutiae and ridges of the fingerprint. The minutiae that remain after the pruning can be used for feature matching.