Extracting the Path of Frame Center Points Using Spatial Transformation and Motion Estimation

A new interactive technique for mobile phones using built-in cameras is presented. Users can use the path that connects center points of frames in the captured image sequence to indicate an object contour or a curve text line. To estimate the camera movement, Speeded-Up Robust Features (SURF) is used to estimate the spatial transformation parameters between the previous and current frames. These parameters are then used to recalculate the locations of the center points in the previous frame into the current frame. Finally, the motion estimation with a small search range is applied to refine the locations of the center points. The experimental results obtained from real image sequences show that the proposed method can generate accurate and stable results.