A method of capturing writing or drawing on a whiteboard comprises inputting camera data for a succession of image frames of the whiteboard, and processing data from said image frames to remove parts of the image frames corresponding to parts of a user or user pen writing or drawing on the whiteboard. The processing involves filtering to distinguish between i) motion of the user/user pen parts in the image frames, and ii) writing/drawing image information in the image frames which appears or changes during said writing or drawing but which is thereafter substantially unchanging. The filtered data defines captured writing or drawing from the whiteboard.