CPF Algorithm Overview

FrameFree® technology can be roughly separated into two phases: (1) encoding to compute the mapping between images and (2) decoding to render the in-between frames from original images and their mapping.

CPF (Critical Point Filters) is the core algorithm used in the FrameFree® encoding process. CPF is a pixel matching algorithm to automatically generate the mapping data representing the correspondence between every pixel of any two arbitrary images. These mapping data files, which are typically only about 2-3 kilobytes, replace a large number of in-between frames to reduce the data volume drastically. Compression is extreme, sometime reaching 1/10,000.


Taking the original images (referred to as Key Frames) and mapping data, the decoding process renders in-between frames in real-time. Any number of in-between frames can be generated - both during the authoring process and the playback process. This allows full speed control (from super slow-motion to ultra fast motion) and true user interactivity such as auto zoom, pan and shifting of viewpoints.

The quality of the FrameFree® movie is limited only by the quality of the Key Frames -- it can support resolutions way beyond the HD specification (up to 4096x4096). Various still image formats are supported for the key frames, and the interpolation method can be either linear or B-Spline-based.