Patent ID: 8369407

Claim:
A method of indexing a video document, comprising the following steps: (a) representing the video document in the form of a parallelepipedal volume obtained by juxtaposing on a time axis (t) K successive frames constituting the video document, each frame being represented by a matrix of pixels in a two-dimensional space (x, y); and (b) constructing a space-time video slice (STVS α ) of the video document by extracting a one-dimensional segment of pixels for each frame of the video document in the same direction at a predetermined angle α relative to a first direction (x) of the frames, juxtaposing the K segments of pixels corresponding to the K frames on a time axis (t) to form a space-time video slice (STVS α ) of length (WSTVS α ) defined by the K juxtaposed pixel segments and of height (HSTVS α ) equal to the length of the segments extracted from each of the frames, which length is a function of the dimension of the frames in the second direction (y) and the angle α, and initializing the colorimetric values of the pixels of the K segments of the space-time video slice (STVS α ) on the basis of the content of the segments extracted from the K frames of the video document, characterized in that the height (HSTVS α ) of a space-time video slice (STVS α ) depends on the angle α formed by the K segments of the space-time video slice (STVS α ) relative to the first direction (x) of the frames, the width (W frame ), and the height (H frame ) of the frame, as follows: H STVS α = {  W frame cos ⁢ ⁢ α  if ⁢ ⁢ ( - α diag < α < α diag ⁢ ⁢ or ⁢ ⁢ π - α diag < α < π + α diag )  H frame sin ⁢ ⁢ α  Otherwise where α diag represents the angle between the first diagonal interframe and one of the lines in the first direction x, and where: α diag = arctan ⁡ ( W frame H frame ) .