Object class identification, verification of object image synthesis

A method of verifying the identity of an object class using a model based upon appearance parameters derived by comparing images of objects of different classes, the model including a representation of a probability density function describing the variation of appearance parameters for a given class of object, the model function including a defined relationship between the shape of the probability density function and the location of the probability density function in appearance space, wherein for an object class for which verification will subsequently be required, the method comprises:

• using a series of images of that object class to generate a representation of a specific probability density function describing the variation of appearance parameters for that object class, and
• during subsequent verification of the object class, comparing an image of an object of an unknown class with the object of known class by generating appearance parameters representative of the object of unknown class and iteratively modifying at least some of the appearance parameters within limits determined using the specific probability density function, to provide a set of appearance parameters which are compared with a predetermined threshold to provide verification.

A method of generating a synthesized image of an object class using a model based upon appearance parameters derived by comparing images of objects of different classes, the model including a representation of a probability density function describing the variation of appearance parameters for a given class of object, the model further including a defined relationship between the shape of the probability density function and the location of the probability density function in appearance space, wherein for an object class to be synthesized, the method comprises:

• using a series of images of that object class to generate a representation of a specific probability density function describing the variation of appearance parameters for that object class, and
• during subsequent synthesis of the object class, confining the appearance parameters used within limits determined using the specific probability density function.