point cloud

A set of data points in space representing position coordinates. In point cloud analysis, algorithms compare data points in multiple images to track movement of objects in video footage.

When you use the Point Cloud analysis method in Motion’s tracking behaviors to analyze the motion of a reference pattern in a clip, the analysis samples many point positions in the search region around the center point of the tracker. Some of those points fit the designated reference pattern more closely than others; the tracker finds the point where the search region most closely matches the reference pattern (with subpixel accuracy). For every frame analyzed, the tracker assigns a correlation value by measuring how close the best match is.

In addition to searching for the reference pattern’s position, the tracker identifies how the pattern transforms (scales, rotates, or shears) from one frame to the next.