Figure 4From: Automated ventricular systems segmentation in brain CT images by combining low-level segmentation and high-level template matchingSymmetry cost calculation. The input is the edge of skull. The difference between distances from each side to the rotation center line is calculated and summed for all rows. The smaller the symmetry cost, the better the symmetry. The l1 and r1 actually begins at the top line of the skull (the ellipse), l n and r n are actually on the last row of the skull.Back to article page