Motion estimation

• US 6,445,741 B1
• Filed: 04/26/2001
• Issued: 09/03/2002
• Est. Priority Date: 10/15/1997
• Status: Expired due to Term

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: De Haan, Gerard, Bellers, Erwin B.
• Primary Examiner(s): LEE, RICHARD J
• Application Number:
  US09/843,430
• Time in Patent Office: 495 Days
• Field of Search: H04/N.732, 348/441, 348/451, 348/452, 348/699, 375/240.01, 375/240-2-2, 375/240.21, 375/240.24, 375/240.25
• US Class Current: 375/240.16
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence

Abstract

In a method of estimating motion vectors from subsampled video data (I), first vectors are estimated (ME, PM2) between an image with a first sub-sampling phase and an earlier image sub-sampled with a second sub-sampling phase, second vectors are estimated (ME, PM1) between an image with a second sub-sampling phase and an earlier image sub-sampled with a first subsampling phase, and the first and second vectors are combined (CD) to obtain output motion vectors (MV).

Claims

1. A method of estimating motion vectors from sub-sampled video data, the method comprising the steps:

recursively estimating, by means of a motion estimator and a first vector prediction memory, first vectors between a first current image with a first sub-sampling phase and an earlier image sub-sampled with a second sub-sampling phase;

recursively estimating, by means of said motion estimator and a second vector prediction memory, second vectors between a second current image with the second sub-sampling phase and said first current image sub-sampled with the first sub-sampling phase; and

combining said first and second vectors.

2. The method as claimed in claim 1, wherein said sub-sampled video data is interlaced video data, said image with the first sub-sampling phase is an odd field, and said image sub-sampled with the second sub-sampling phase is an even field.

3. A device for estimating motion vectors from sub-sampled video data, the device comprising:

a first vector prediction memory and a second vector prediction memory separate from said first vector prediction memory;

means for recursively estimating, using said first vector prediction memory, first vectors between a first current image with a first sub-sampling phase and an earlier image sub-sampled with a second sub-sampling phase, and for estimating, using said second vector prediction memory, second vectors between a second current image with the second sub-sampling phase and said first current image sub-sampled with the first sub-sampling phase; and

means for combining said first and second vectors.

4. An image signal display apparatus, comprising:

the motion vector estimating device as claimed in claim 3 for furnishing motion vectors;

a motion compensated interpolator for generating an output image signal; and

a display device for displaying the output image signal.

5. A device for estimating motion vectors from sub-sampled video data, the device comprising:

means for estimating first vectors between an image with a first sub-sampling phase and an earlier image sub-sampled with a second sub-sampling phase;

means for estimating second vectors between an image with the second sub-sampling phase and an earlier image sub-sampled with the first sub-sampling phase; and

means for combining said first and second vectors, wherein said combining means sets an output vector y-component to zero in case the signs of respective y-components of said first and said second vectors differ.

7. An image signal display apparatus comprising:

the device for estimating motion vectors as claimed in claim 5 for furnishing motion vectors;

a motion compensated interpolator for generating an output image signal; and

a display device for displaying the output image signal.

6. A device for estimating motion vectors from sub-sampled video data, the device comprising:

means for estimating first vectors between an image with a first sub-sampling phase and an earlier image sub-sampled with a second sub-sampling phase;

means for estimating second vectors between an image with the second sub-sampling phase and an earlier image sub-sampled with the first sub-sampling phase; and

means for combining said first and second vectors, wherein said combining means sets an output vector y-component to an even value in case values of respective y-components of said first and said second vectors lie close to, but on mutually different sides of said even value.

8. An image signal display apparatus comprising:

the device for estimating motion vectors as claimed in claim 6 for furnishing motion vectors;

a motion compensated interpolator for generating an output image signal; and

a display device for displaying the output image signal.