# US 6,295,377 B1 · Combined spline and block based motion estimation for coding a sequence of video images

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 6,295,377 B1
- Document ID: US6295377B1
- Status: Granted
- Kind: B1
- Application number: 09/114,684
- Filed: 1998-07-13
- Granted: 2001-09-25
- Earliest claimed: 1998-07-13
- Assignees: Compaq Computer Corporation
- Inventors: Frederic Dufaux; Sing Bing Kang
- Web page: https://patentgrep.com/patent/US6295377B1

## CPC

- G06T 9/004: {Predictors, e.g. intraframe, interframe coding}
- G06T 7/238: using non-full search, e.g. three-step search
- G06T 2207/10016: Video; Image sequence
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL

## Abstract

In an coder for producing a bitstream representative of a sequence of video images, a previous image is registered with a current image using spline-based registration to produce estimated motion vectors. The estimated motion vectors are used to match blocks of the previous image and the current image to produce translation vectors. The translation vectors compensate for motion while encoding the sequence as a bitstream.

## Claims

### Claim 1

A method for estimating motion in a sequence of images, comprising the steps of;
registering a previous image with a current image using 2-D splines created by a gradient technique based on pixel intensity to estimate the displacement of grid nodes and to produce estimated motion vectors; and
matching blocks of the previous image and the current image using the estimated motion vectors to establish a search starting point and to reduce a search area to produce translation vectors.

### Claim 2 (depends on 1)

The method of claim 1 including compensating for motion between the previous frame and the current frame using the translation vectors.

### Claim 3 (depends on 1)

The method of claim 1 including compensating for motion while encoding of a video sequence.

### Claim 4 (depends on 1)

The method of claim 1 including compensating for motion while restoring images of the sequence.

### Claim 5 (depends on 1)

The method of claim 1 including compensating for motion while filtering images of the sequence.

### Claim 6 (depends on 1)

The method of claim 1 including interpolating and rounding the estimated motion vectors.

### Claim 7 (depends on 1)

The method of claim 1 including:
determining if the estimated motion vectors are less than a predetermined threshold;
determining the sum of absolute differences for the estimated motion vectors and a dense motion vector;
setting the estimated motion vectors to zero when the dense motion vector minus a skew is less than the sum.

### Claim 8

An apparatus for estimating motion in a sequence, of images, comprises:
means for registering a previous image with a current image using 2-D splines created by a gradient technique based on pixel intensity to estimate the displacement or grid nodes and to produce estimated motion vectors; and
means for matching blocks of the previous image and the current image using the estimated motion vectors to establish a search starting point and to reduce a search area to produce translation vectors.