This object is a tool that takes in an image region containing some object
and outputs a "shape" or set of point locations that define the pose of the
object. The classic example of this is human face pose prediction, where
you take an image of a human face as input and are expected to identify the
locations of important facial landmarks such as the corners of the mouth
and eyes, tip of the nose, and so forth. For example, here is the output
of dlib's <ahref="http://sourceforge.net/projects/dclib/files/dlib/v18.10/shape_predictor_68_face_landmarks.dat.bz2">68-face-landmark shape_predictor</a> on an image from the HELEN dataset: <br/><br/>
<imgsrc='face_landmarking_example.png'/>
<br/><br/>
To create useful instantiations of this object you need to use the
<ahref="ml.html#shape_predictor_trainer">shape_predictor_trainer</a> object to train a
shape_predictor using a set of training images, each annotated with shapes you want to predict.
To do this, the shape_predictor_trainer uses the state-of-the-art method from the
paper:
<blockquote>
One Millisecond Face Alignment with an Ensemble of Regression Trees