What is disclosed is a system and method for automatically segmenting a breast from surrounding tissue in a thermal image. A thermal image of at least one breast of the patient is received. The thermal image is then analyzed to identify a set of N points around the breast a contour of an outline of the body and isotherms of the axilla and infra-mammary fold. Thereafter the points are connected together to form a N-sided irregular polygon which segments the breast from surrounding tissue. Each of the points is a vertex of the polygon and comprises a draggable object which enables a user to selectively manipulate a shape of the polygon. A user can add/delete vertices from the polygon as desired. The area of the image encompassed by the polygon is communicated to a breast cancer screening algorithm performing automated or semi- automated screening.
