US 2018/0324449 A1 · METHOD AND APPARATUS FOR COMMUNICATING AND RECOVERING MOTION INFORMATION

Abstract

This invention describes a method for communicating crude motion information using tracking metadata and recovering more accurate motion information from the received tracking metadata and partial video frame data; in particular, we use metadata to convey crude boundaries of objects in the scene and signal motion information for these objects. The proposed method leaves the task of identifying the exact boundaries of an object to the decoder/client. The proposed method is particularly appealing when metadata itself carries semantics that the client is interested in, such as tracking information in surveillance applications, because, in this case, metadata does not constitute an overhead. The proposed method involves motion descriptions that can be used to predict the appearance of an object in any one frame from its appearance in any other frame that contains the object. That is, the motion information itself allows locations within an object to be invertibly mapped to locations within the same object in any other relevant frame. This is a departure from conventional motion coding schemes, which tightly-couple motion information to the prediction strategy. This property makes the proposed method particularly suitable for applications which require flexible access to the content.

Claims32

Dependent claims

A method for recovering motion information within multiple frame media content, using video frame sample data for some frames, together with motion data that carries some information about the motion between frames, comprising the following steps:

(a) selection of two or more reference frames to be used in predicting a further frame;
(b) using the motion data to identify at least two spatial domains within a first reference frame, to group each of these with a corresponding spatial domain in each other reference frame, and to determine a parametric representation of motion between corresponding domains in different reference frames;
(c) using the motion representations, domain correspondences and reference video frame sample values to determine validity information for each overlapping domain within the first reference frame;
(d) using the parametric motion representations, domain correspondences and reference video frame sample values to determine validity information for each overlapping domain within each other reference frame;
(e) using the parametric motion representations, validity information and reference frame sample values to form a prediction of said further frame.

2 more elements

A multiresolution method for comparing two images over a spatial domain of interest to determine a set of likelihood ratios for each resolution level, in which each location within the resolution level has its own likelihood ratio that expresses the probability that the spatial features of the two images are matched at said location, divided by the probability that the spatial features of the two images are not matched at said location, comprising the steps of:

(a) decomposing each image into a multi-resolution hierarchy;
(b) determining a first set of likelihood ratios for each resolution level based on spatial neighbourhoods of the associated locations in each of the two images within said resolution level;
(c) determining a second set of likelihood ratios for each resolution level by combining the first set of likelihood ratios with the final set of likelihood ratios determined at a lower resolution level, except at the lowest resolution level, where the first and second sets of likelihood ratios are the same.

Dependencies are inferred from the claim text.

Method and apparatus for communicating and recovering motion information

Life of this patent

Method and apparatus for communicating and recovering motion information

Life of this patent

Abstract

Claims32