1. A modification method for modifying an expression of an individual in at least one video frame, said modification method being based on a model of the individual derived from a plurality of video frames of video footage, while a pose of the individual's performance that is associated with each video frame is retained, the individual being characterized by a shape, the method comprising: a. identifying a plurality of control points with respect to the individual for characterizing the shape of the individual; b. characterizing at least one feature of the individual in each frame of the video footage by a shape vector, the shape vector comprising x and y image coordinate positions of the plurality of control points; c. warping each shape vector of each frame to a common standard frame thereby generating an aligned shape vector and a transformed image for each frame; d. representing values of pixels of the transformed image as a texture vector; e. specifying a subset of the plurality of control points as belonging to a group of pose control points; f. creating a first model to predict a control expression shape vector from the group of pose control points; g. creating a further model to predict a texture vector from the plurality of control points; h. extracting a set of exemplar frames from among the plurality of video frames of video footage to serve as a basis for expression manipulation; i. representing each frame of the basis for expression manipulation as a difference between observed shape and texture vectors and the control expression shape and texture vectors predicted in steps (f) and (g) from the plurality of control points; j. transforming each shape vector for each frame in accordance with specified pose control points and weights applied to the said basis for expression manipulation in such a manner as to create new shape and new texture vectors; and k. reinserting the new shape and new texture vectors into the sequence of frames so as to create a graphical depiction of the individual bearing a modified expression.