Patent ID: 6349114
Filing Date: 2002-02-19
Classification: H04N

Abstract:
A camera motion parameters estimation method provided for considering a sequence of successive video frames subdivided into blocks and processing this sequence, wherein said processing operation comprises the successive steps of:extracting from said video sequence vectors corresponding to the motion between two successive frames, said motion vectors forming the camera velocity field; preprocessing the camera velocity field, in order to reduce the amount of data and the heterogeneousness of said extracted motion vectors; estimating for each pair of frames, from said preprocessed field, camera features between the two considered frames; undertaking on the basis of said estimation a long term motion analysis to obtain motion descriptors corresponding to the estimated camera motion parameters; wherein said preprocessing sub-step includes the computing operation of a vector representing the motion of a new block according to the motion vectors of the four original blocks and of an associated confidence level; wherein said confidence level is given by the distance from each vector to its neighbourhood; wherein said neighbourhood is represented by a value {right arrow over (V)}(m) such as the mean value or the median, leading for the confidence mask to a value Ci,j having an expression of the type: Ci,j=eâˆ’&par;{right arrow over (v)}i,jâˆ’{right arrow over (v)}(m)&par;2 where (i,j) defines the original block and {right arrow over (V)}i,j its original motion vector.