Computer generated head

A method of animating a computer generation of a head, the head having a mouth which moves in accordance with speech to be output by the head,

• said method comprising:
• providing an input related to the speech which is to be output by the movement of the mouth;
• dividing said input into a sequence of acoustic units;
• converting said sequence of acoustic units to a sequence of image vectors using a statistical model, wherein said model has a plurality of model parameters describing probability distributions which relate an acoustic unit to an image vector, said image vector comprising a plurality of parameters which define a face of said head;
• and
• outputting said sequence of image vectors as video such that the mouth of said head moves to mime the speech associated with the input text,
• wherein the image parameters define the face of a head using an appearance model comprising a plurality of shape modes and a corresponding plurality of appearance modes, wherein the shape modes define a mesh of vertices which represents points of the face of said head and the appearance modes represent colours of pixels of the said face, the face being generated by combining a weighted sum of shape modes and a weighted sum of appearance modes, the weighting being provided by said image parameters.

A method of adapting a first model for rendering a computer generated head to extend to a further spatial domain, wherein the first model comprises a plurality of shape modes and a corresponding plurality of appearance modes, wherein the shape modes define a mesh of vertices which represents points of the face of said head and the appearance modes represent colours of pixels of the said face, the face being generated by combining a weighted sum of shape modes and a weighted sum of appearance modes;

• the method comprising:
• receiving a plurality of training images comprising a spatial domain to which the model is to be extended, the training images being used to train the first model;
• labelling points in the new domain;
• determining new shape and appearance modes to fit the training images while keeping the weights of the first model the same.

A system for animating a computer generation of a head, the head having a mouth which moves in accordance with speech to be output by the head,

• the system comprising a processor which is configured to:
• receive an input related to the speech which is to be output by the movement of the lips;
• divide said input into a sequence of acoustic units;
• select an expression to be output by said head;
• convert said sequence of acoustic units to a sequence of image vectors using a statistical model, wherein said model has a plurality of model parameters describing probability distributions which relate an acoustic unit to an image vector for a selected expression, said image vector comprising a plurality of parameters which define a face of said head;
• and
• output said sequence of image vectors as video such that the lips of said head move to mime the speech associated with the input text with the selected expression,
• wherein the image parameters define the face of a head using an appearance model comprising a plurality of shape modes and a corresponding plurality of appearance modes, wherein the shape modes define a mesh of vertices which represents points of the face of said head and the appearance modes represent colours of pixels of the said face, the face being generated by combining a weighted sum of shape modes and a weighted sum of appearance modes, the weighting being provided by said image parameters.

A system for animating a computer generation of a head, the head having a mouth which moves in accordance with speech to be output by the head,

• the system comprising a processor, the processor being adapted to:
• receive an input related to the speech which is to be output by the movement of the lips;
• divide said input into a sequence of acoustic units;
• convert said sequence of acoustic units to a sequence of image vectors using a statistical model, wherein said model has a plurality of model parameters describing probability distributions which relate an acoustic unit to an image vector, said image vector comprising a plurality of parameters which define a face of said head;
• and
• output said sequence of image vectors as video such that the lips of said head move to mime the speech associated with the input text,
• wherein the image parameters define the face of a head using an appearance model comprising a plurality of shape modes and a corresponding plurality of appearance modes, wherein the shape modes define a mesh of vertices which represents points of the face of said head and the appearance modes represent colours of pixels of the said face, the face being generated by combining a weighted sum of shape modes and a weighted sum of appearance modes, the weighting being provided by said image parameters.