Television – Image signal processing circuitry specific to television – Motion vector generation
Patent
1991-04-29
1994-09-27
Britton, Howard W.
Television
Image signal processing circuitry specific to television
Motion vector generation
348407, 348413, 348416, H04N 7137
Patent
active
053510950
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of image processing, and more particularly to motion estimation used in image transmission chains with a view, in particular, to reducing the information throughput, and aims at a method and the corresponding device for estimating and hierarchically coding the motion of sequences of images.
2. Discussion of the Background
Motion estimation information is increasingly used in all parts of a high-definition television transmission chain:
Thus, motion estimation becomes an important function in the, in particular high-definition, image transmission chain.
Currently, each item of equipment in the transmission chain has its own motion estimator. It therefore seems of great interest to provide a single motion estimator, in the production studio, which is able to feed each item of equipment in the high-definition television chain. But, as each item of equipment does not require the same characteristics for the motion information, the single motion estimator must have several possible outputs, or be parametrizable.
SUMMARY OF THE INVENTION
The aim of the invention is a method and the corresponding device for estimating and coding motion, developed to enable the simple coding of sequences of images, this motion information being exactly suited to a "quadtree" type coding to which, in addition, a throughput adjustment is easily applicable.
Moreover, with the goal of avoiding a motion estimation operation at reception which would increase the complexity of the receiver, this motion information can be transmitted, in particular on an auxiliary digital data transmission channel for assisting the decoding of sequences of images. Several advantages result from an estimation of motion at the production studio: motion estimating system may be higher at the production studio than they could be in an item of receiving equipment; thus, a powerful and solid motion estimator may be constructed; sequence of images to be coded is available and that the motion estimation is therefore more powerful; perturbed by transmission noise.
According to the invention, a method for estimating and hierarchically coding the motion of sequences of images, is characterized in that it consists: .times.2.sup.p+1 pixel macroblocks and in determining a first field of motion vectors, which is associated with this partition into macroblocks, by using an iterative and recursive estimation algorithm initialized by motion vectors estimated for the preceding image, macroblocks and in determining, for the blocks which result therefrom, a second motion vector field by using the same estimation algorithm but initialized by vectors from the field of motion which was estimated at the preceding level, considered at the i-1 level into quadrants and in determining, for the blocks which result therefrom, an ith motion vector field by using the same estimation algorithm initialized by vectors from the field of motion which were estimated at the preceding level, the blocks of minimum size being 2.sup.l+1 .multidot.2.sup.l+1 pixel blocks, vector fields by choosing the lowest level of partition for which the motion vector associated with the corresponding block leads to the minimization of a criterion reflecting the differences of brightness between blocks communicating in the successive images via the estimated displacement vectors.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and other characteristics will emerge with the aid of the description which follows whilst referring to the attached figures.
FIG. 1 illustrates the information conventionally used for estimating a field of motion;
FIG. 2 illustrates the information used to estimate a field of motion according to the invention;
FIG. 3 illustrates the partitioning of a macroblock into smaller blocks in accordance with 5 hierarchical levels;
FIG. 4 illustrates the chaining of the steps of the motion estimation method according to the invention;
FIGS. 5a, 5b, 5c and 5d illustrate the displac
REFERENCES:
patent: 4924310 (1990-05-01), von Brandt
patent: 5150209 (1992-09-01), Baker
patent: 5155594 (1992-10-01), Bernstein
Strobach, P. : "Quadtree-Structured linear prediction models for image sequence processing", pp. 742-748, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 11, No. 7, Jul. 1989, New York.
Williams, L. R. et al, "A coarse-to-fine control strategy for stereo and motion on a mesh-connected computer", pp. 219-226, Proceedings IEEE Computer Society Conference on Computer Vision and Pattern Processing, Jun. 22-26, 1986, Washington.
Proceedings Workshop on Motion: Representation and Analysis, Charleston, South Carolina May 7-9, 1986, IEEE, (Washington, US), W. Enkelmann: "Investigations of multigrid algorithms for the estimation of optical flow fields in image sequences", pp. 81-87.
Britton Howard W.
Thomson Consumer Electronics
LandOfFree
Method and device for estimating and hierarchically coding the m does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for estimating and hierarchically coding the m, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for estimating and hierarchically coding the m will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1268675