US 6,205,175 B1 · Method and apparatus for encoding a contour of an object in a video signal by employing a vertex coding technique

Abstract

In a method for encoding a contour of an object in a video signal based on a vertex information representing a position and an index of an octant corresponding to each vertex of the contour, a maximum length line segment (MLLS) is first detected among line segments for the contour based on the vertex information (VI). Then, an initial vertex position information (IVPI) and a final vertex position information (FVPI) for the contour are encoded, the initial vertex and the final vertex being two vertices constituting the MLLS. Thereafter, a first bit number (FBN) and a second bit number (SBN) for the contour are set, wherein the FBN is the number of bits required to encode the MLLS and the SBN is the number of bits calculated by using the FBN, typically being FBN-1. In a subsequent step, each of the vertices are classified based on the SBN and the VI either as a first vertex (FV) or as a second vertex (SV) to thereby provide first vertices (FV's) and second vertices (SV's). Then, an escape signal (ECS) for each SV is produced to supply a plurality of ECS's for the SV's. The numbers of the FV's (NFV) and the SV's (NSV) for the contour are calculated, respectively. Thereafter, each of the FV's and the SV's is encoded with either the FBN or the SBN based on the ECS's and the comparison result for the NFV and the NSV to thereby provide encoded FV's and encoded SV's.

Claims16

Dependent claims

A method for encoding a contour of an object in a video signal based on a vertex information representing a position and an index of an octant corresponding to each vertex of the contour by using an octant-based vertex coding technique, wherein a plurality of vertices are determined on the contour and each of contour segments defined two adjacent vertices is approximated by corresponding one of line segments joining the two adjacent vertices, the method comprising the steps of:

(a) detecting a maximum length line segment (MLLS) among the line segments for the contour based on the vertex information;
(b) encoding an initial vertex position information (IVPI) and a final vertex position information (FVPI) for the contour, wherein the initial vertex and the final vertex are two vertices constituting the MLLS;
(c) setting a first bit number (FBN) and a second bit number (SBN) for the contour, wherein the FBN is the number of bits required to encode the MLLS and the SBN is the number of bits calculated by using the FBN in accordance with a preset calculation rule, the SBN being smaller than the FBN;
(d) classifying, based on the SBN and the vertex information, each of the vertices either as a first vertex or as a second vertex in accordance with a preset classification rule to thereby provide first vertices (FV's) and second vertices (SV's);
(e) producing an escape signal (ECS) for each second vertex to thereby supply a plurality of ECS's for the SV's;
and
(f) calculating the number of the FV's (NFV) and the number of the SV's (NSV) for the contour.

4 more elements

An apparatus for encoding a contour of an object in a video signal based on a vertex information representing a position and an index of an octant corresponding to each vertex of the contour by using an octant-based vertex coding technique, wherein a plurality of vertices are determined on the contour and each of contour segments defined by two adjacent vertices is approximated by corresponding one of line segments joining the two adjacent vertices, the apparatus comprising:

means, based on the vertex information, for detecting a maximum length line segment (MLLS) among the line segments for the contour and then setting a first bit number (FBN) and a second bit number (SBN) for the contour and at the same time providing an initial vertex position information (IVPI) and a final vertex position information (FVPI), wherein the initial vertex and the final vertex are two vertices constituting the MLLS, respectively;
the FBN is the number of bits required to encode the MLLS;
the SBN is the number of bits calculated by using the FBN in accordance with a preset calculation rule;
and the SBN is smaller than the FBN;
means, based on the SBN and the vertex information, for classifying each of the vertices either as a first vertex or as a second vertex in accordance with a preset classification rule to thereby provide first vertices (FV's) and second vertices (SV's);
means for calculating the number of FV's (NFV) for the contour;
means for calculating the number of the SV's (NSV) for the contour and producing an escape signal (ECS) for each second vertex to thereby supply the NSV and a plurality of ECS's for the SV's;
and
means for comparing (NFV/NSV) with a predetermined threshold value TH, thereby supplying the FV's and the SV's if (NFV/NSV)>TH;
and supplying the FV's, the SV's and the ECS's and at the same time generating an indication signal for the contour if (NFV/NSV)≦TH.

7 more elements

Dependencies are inferred from the claim text.

Method and apparatus for encoding a contour of an object in a video signal by employing a vertex coding technique

Life of this patent

Method and apparatus for encoding a contour of an object in a video signal by employing a vertex coding technique

Life of this patent

Abstract

Claims16