As mentioned previously, AAMs require a shape model, and this role is played by Active Shape Models (ASMs). In the coming sections, we will create an ASM that is a statistical model of shape variation. The shape model is generated through the combination of shape variations. A training set of labeled images is required, as described in the article Active Shape Models – Their Training and Application, by Timothy Cootes. In order to build a face-shape model, several images marked with points on key positions of a face are required to outline the main features. The following screenshot shows such an example: