Published online Dec 10, 2014. doi: 10.5306/wjco.v5.i5.1055
Revised: May 30, 2014
Accepted: June 14, 2014
Published online: December 10, 2014
Processing time: 400 Days and 20.9 Hours
AIM: To achieve symmetric boundaries for left and right breasts boundaries in thermal images by registration.
METHODS: The proposed method for registration consists of two steps. In the first step, shape context, an approach as presented by Belongie and Malik was applied for registration of two breast boundaries. The shape context is an approach to measure shape similarity. Two sets of finite sample points from shape contours of two breasts are then presented. Consequently, the correspondences between the two shapes are found. By finding correspondences, the sample point which has the most similar shape context is obtained.
RESULTS: In this study, a line up transformation which maps one shape onto the other has been estimated in order to complete shape. The used of a thin plate spline permitted good estimation of a plane transformation which has capability to map unselective points from one shape onto the other. The obtained aligning transformation of boundaries points has been applied successfully to map the two breasts interior points. Some of advantages for using shape context method in this work are as follows: (1) no special land marks or key points are needed; (2) it is tolerant to all common shape deformation; and (3) although it is uncomplicated and straightforward to use, it gives remarkably powerful descriptor for point sets significantly upgrading point set registration. Results are very promising. The proposed algorithm was implemented for 32 cases. Boundary registration is done perfectly for 28 cases.
CONCLUSION: We used shape contexts method that is simple and easy to implement to achieve symmetric boundaries for left and right breasts boundaries in thermal images.
Core tip: Breast thermography has shown to be as a non-invasive safe method to detect breast abnormalities. Comparison between two breast temperature distributions is helpful to identify irregularities. Since in many cases real thermal breast images do not have symmetric boundaries, a registration is needed. A registration shape context approach is applied in this work.