Abstract Background In the active shape model framework. principal component analysis (PCA) based statistical shape models (SSMs) are widely employed to incorporate high-level a priori shape knowledge of the structure to be segmented to achieve robustness. A crucial component of building SSMs is to establish shape correspondence between all training shapes. which is a very challenging... https://www.markbroyard.com/flash-grab-hobbit-door-on-sale-limited-grab/