| 摘要 |
The application discloses an apparatus and method of processing images, hand-drawn or written on a suitable Writing Surface, viewed by an Image Sensor such as a video camera, and captured by an image sensing circuit (i.e., frame grabber or similar) used for acquisition of image frames by a computer. More particularly, this invention discriminates among changes detected in these Viewed Images in order to identify and disregard non-informational, transient and/or redundant content. Removal of such content, a writer's arm for example, from the captured image facilitates isolating meaningful changes, specifically intentional new Writings and Erasures appearing on the Writing Surface. Preserving only meaningful changes on the surface promotes optimized: "video image" storage and compressed transmission of a subset of the visual data, when used in conjunction with digital computers at remote locations optionally equipped with projected image and/or conventional computer display systems. The invention provides for displaying a composite of the remote sites' changes, transmitted over conventional communications channels, omitting Local Markings where the display device is a projector. The preferred embodiment of the present invention is applied to remote presentation aids, in particular "whiteboards" such as those typically used in educational lectures and commercial sales and training settings, and in particular to remote whiteboards. As will become clear, however, the application of the present invention is not restricted to whiteboards exclusively, but can work with any Writing Surface suitable for image acquisition (e.g., flipcharts or paper on a desk). Receive-only sites may participate in the remote presentation without contributing Local Markings to the composite. The present invention is compatible with conventional software products which will carry audio and other data streams on the same channel as the compressed image signals.
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