Lung nodules are tiny lumps of tissue that are common in the lungs. The nodule may be benign or
malignant; malignant nodules are cancerous and can grow rapidly. For a long time, X-ray images of the
chest have been utilized to diagnose lung cancer. We developed in this paper a computer aid diagnosis
system (CAD) to atomically classify a set of lung x-ray images into normal and abnormal (with nodule and
no-nodule) cases.