Techniques are presented for modifying images of an object in video, for example to correct for lens distortion, or to beautify a face. These techniques include extracting and validating features of an object from a source video frame, tracking those features over time, estimating a pose of the object, modifying a 3D model of the object based on the features, and rendering a modified video frame based on the modified 3D model and modified intrinsic and extrinsic matrices. These techniques may be applied in real-time to an object in a sequence of video frames.