1. A computer method of processing video data comprising the computer implemented steps of: receiving video data formed of a series of video frames; and encoding portions of the video frames by: detecting one or more instances of a candidate feature in one or more of the video frames; said detection determining positional information for instances in the one or more previously decoded video frames, the positional information including a frame number, a position within that frame, and a spatial perimeter of the instance; said candidate feature being a set of one or more detected instances; predicting, by a motion compensated prediction process, a portion of a current video frame in the series using one or more previously decoded video frames; said motion compensated prediction process being initialized with positional predictions, where the positional predictions provide the positional information from detected feature instances in previously decoded video frames; using one or more of the candidate feature instances that are transformed by augmenting the motion compensated prediction process, defining one or more features along with the transformed instances to create a first feature-based model, the first feature-based model enabling prediction in the current frame of an appearance and a source position of a substantially matching feature instance, where the substantially matching feature instance is a key feature instance; comparing the first feature-based model to a conventional video encoding model of the one or more defined features, and determining from the comparison which model enables greater encoding compression; and using results of the comparing and determining step, applying feature-based encoding to portions of one or more of the video frames, and applying conventional video encoding to other portions of the one or more video frames.