Patent ID: 6496606
Filing Date: 2002-12-17
Classification: G06K,G06T,H04N

Abstract:
A method for generating a large static image M(n), such as a sprite or a mosaic, from a video sequence including successive video objects VOs, said method comprising the steps of:(A) estimating motion parameters related to the current video object V0(n) of the sequence, with respect to the previously generated static image M(nâˆ’1); (B) warping said current video object V0(n), on the basis of said estimated motion parameters; (C) blending the warped video object WV0(n) thus obtained with the previously generated static image M(nâˆ’1); characterized in that:(1) said method also comprises, between said warping and blending steps, an additional step for computing, for each picture element of the current video object V0(n), a weighting coefficient wWF(n)[x,y] correlated to the error between the warped video object WV0(n) and the static image M(nâˆ’1) at each picture element [x,y]; (2) wherein the blending step takes into account said weighting coefficients according to a blending formula for determining the static image M(n), the blending formula being defined as follows for each pixel [x,y]: M&af;(n)&af;[x,y]=wM&af;(n-1)&af;[x,y]&CenterDot;M&it;(n-1)&af;[x,y]+wWF&af;(n)&af;[x,y]&CenterDot;WF&it;(n)&af;[x,y]wM&af;(n-1)+wWF&af;(n)â€ƒwhere the definitions of the terms are the following: (a) n>0 (b) whatever (x,y), wM(0)=0; (c) whatever (x,y), wWF(n)[x,y]=wWF&it;(n)&af;[x,y]=1r&it;(x,y)&it;&dd;&dd;r&it;Ï &it;(r&it;(x,y));(d) wM(n)=wM(nâˆ’1)+wWF(n).