Method and apparatus for selectively encoding and decoding a digital motion video signal at multiple resolution levels

A method of encoding a digital motion video signal comprising the steps of:

• a--selecting at least one frame from a sequence of frames of said digital motion video signal;
• b--encoding each selected frame as a still image including the steps of:
• (1) resolving each selected frame into at least one lower level of resolution;
• and
• (2) encoding at least one of the lower levels of resolution but not encoding the full resolution level;
• and
• c--encoding each non-selected frame of said digital motion video signal using at least the full level of resolution.

An apparatus for encoding a digital motion video signal comprising:

• a--means for selecting at least one frame from a sequence of frames of said digital motion video signal;
• b--means for resolving each selected frame into at least one lower level of resolution;
• c--means for encoding at least one lower resolution level of each of said selected frames;
• and
• d--means for encoding each non-selected frame of said digital motion video signal using only the full resolution level.

A method of decoding a digital motion video signal in which at least one selected frame from a sequence of frames has been resolved into at least one lower level of resolution which is then encoded, and in which each non-selected frame has been encoded at the full resolution level only, said method comprising the steps of:

• a--decoding each level of resolution of each selected frame to form a correction image comprising an array of pixel values having that level of resolution;
• b--forming a result image at each level of resolution by adding the pixel values in a reference image having that level of resolution to the pixel values of the expansion of the correction image to the same level of resolution;
• and
• c--decoding said non-selected frames.

An apparatus for decoding a digital motion video signal comprising:

• a--means for applying a digital motion video signal in which at least one selected frame from a sequence of frames has been resolved into at least one lower level of resolution which is then encoded, and in which each non-selected frame has been encoded at the " full resolution level only;
• b--means for decoding each level of resolution of each selected frame to form a correction image comprising an array of pixel values having that level of resolution;
• c--means for forming a result image at each level of resolution by adding the pixel values in a reference image having that level of resolution to the pixel values of the expansion of the correction image to the same level of resolution;
• and
• d--means for decoding said non-selected frames.