US 5,627,601 A · Motion estimation with bit rate criterion

Abstract

A new motion estimation technique is described herein which directly detects the number of bits required to be transmitted to convey the difference between the predicted video data and the current video data, where a fewer number of bits used to convey the difference corresponds to better motion estimation. The search criterion for the best estimate of movement of a block is the minimum number of bits for conveying this difference instead of minimizing the mean squared error (MSE) or mean average difference (MAD). Thus, complex calculations involving MSD or MAD are avoided. The motion estimator of the preferred embodiment uses a look-up table to convert motion compensated difference signals for a block of pels into the number of bits required to be transmitted to convey the difference signals. When it has been determined that a certain estimated displacement of a block would require the fewest number of bits to be transmitted, that displacement is selected as the best estimate, and the corresponding motion vector is transmitted along with a motion compensated difference signal containing the fewest number of bits.

Claims16

Dependent claims

A method for generating compressed video data comprising the steps of:

receiving video data from a first frame;
generating a difference signal representing differences between said video data from said first frame and video data from a memory storing at least a portion of a previous frame;
motion compensating said video data outputted from said memory if it is determined in said step of generating a difference signal that differences exist between said previous frame and said first frame, said step of motion compensating comprising the steps of:
addressing a look-up table using an address corresponding to said difference signal, which cross-references said difference signal to the number of bits required to be transmitted in order to convey said difference signal;
and
selecting for motion compensation of said video data from said memory a motion vector which produces a fewest number of bits required to be transmitted to convey said difference signal;
and
after said step of motion compensating, transmitting said motion vector and said difference signal which resulted in said fewest number of bits required to convey said difference signal.

5 more elements

In a motion estimation circuit for a video processor system, a method for determining a best estimate shift of motion compensated video data comprising the steps of:

generating a difference signal representative of a difference between a block of video data from a current frame and a first motion compensated block of video data, shifted by a first motion vector, from a previous frame;
determining a number of bits required to convey said difference between said block of video data from said current frame and said first motion compensated block of video data, shifted by said first motion vector, from said previous frame, said step of determining comprising addressing a look-up table using an address corresponding to said difference signal, which cross-references said difference to the number bits needed to be transmitted in order to convey said difference;
repeating said step of determining for a plurality of motion compensated blocks of video data from said previous frame, each of said blocks being shifted by a different motion vector;
selecting a motion vector associated with a difference requiring a fewest number of bits needed to be transmitted to convey said difference;
and
transmitting said motion vector and said difference associated with said fewest number of bits.

3 more elements

Dependencies are inferred from the claim text.

Motion estimation with bit rate criterion

Life of this patent

Motion estimation with bit rate criterion

Life of this patent

Abstract

Claims16