1. A method of microcalcification detection in mammographic images, comprising: forming a plurality of true microcalcification (mcc) clusters from a plurality of cancerous mammographic images that pass a mcc ground truth measure test; forming a plurality of normal clusters from a plurality of normal mammographic images; gathering spot and cluster features from said true mcc clusters and normal clusters; extracting linear structure features in said cancerous mammographic images and normal mammographic images guided by said true mcc clusters and said normal clusters; using said gathered spot and cluster features and said extracted linear structure features in mcc detector training; and applying said mcc detector to mammographic test images which are under testing for cancerous lesions.