Abstract: A passive prop for controlling the operation of a video game through visually detecting and tracking the prop. One aspect of the invention is a spherical prop of principally one color, but with a spot of another color located on the sphere. This provides control of a video system through tracking of position and orientation of the prop. Another aspect of the invention is a planar offset prop consisting of two color regions, a first color region being offset from a second color region. A third aspect of the invention allows the provision of a push-button control for a simple, passive prop, the push-button being effective to cause a color region of a prop to change color.

Abstract: A process and system for synchronizing a video signal to the sampling period of a client system. The synchronization may be suitably implemented by adding or deleting trailing lines from each frame of video data to adjust the frame to match the sampling period of the client system. The synchronization system minimizes the lag between the time a video signal is delivered to the client system and the time the client system responds. The low lag time enhances the responsiveness of the client system to human inputs, and improves the suitability of the overall system to human use. The synchronization system can be achieved using suitable low-cost hardware and is therefore particularly well suited for video game or virtual reality systems designed for home use, increasing the feasibility of employing video inputs in such systems.

Abstract: A method and apparatus for controlling the operation of a video system such as a video game system through recognition of a visual pattern, or key. For example, the presence and identity of the key may enable and select certain features of the video system. The key may suitably consist of a locator mark and a selector mark, the presence of the locator mark identifying the presence of a key, and the selector mark identifying the particular key present. A key recognition system detects the presence of the locator mark and identifies the selector mark. The locator mark is preferably of a distinctive color, readily distinguishable from background objects. The selector mark may be chosen from a limited set of colors, and the color of the selector mark may then be identified to identify the key being used. In another aspect, the locator mark is located in a particular position within the selector mark and is then used by the key detector to scale a rectangle about the selector mark.

Abstract: Compensating for color variations affecting color detection by a video system. In one aspect, compensation for highlights of a prop having multiple color regions is provided. The prop is preferably designed so that every color region of the prop is affected by highlights at the same rate. The color mix ratio for a color region of the prop representing the deviation of the color region from a nominal color value is computed, and an expected color for each color region of the prop is then computed based on the color mix ratio. In another aspect, compensation for variations in a light source illuminating the environment detected by the video system are provided in combination with highlight compensation. A white color balance ratio for a frame of video data is estimated, the color ratios of background white pixels are detected and these ratios are then used to continually update the estimate of the white color balance ratios.

Abstract: A video conference system provides eye contact and a sense of presence to a plurality of conference participants located in respective remotely-sited conference rooms. Each conference room contains at least one video telephone or communications device that includes a video camera for generating video signals indicative of a sequence of local conferee image frames, and an image receiver for displaying image frames of at least one remote conferee. The image receiver, the video camera, and the eyes of the local conferee define a parallax angle. The video conference system further includes a frame generating system, responsive to the video signals, for analyzing local conferee image frames and generating a corresponding sequence of parallax-compensated frames. A signal indicative of each respective sequence of parallax-compensated frames is transmitted to a corresponding image receiver, whereby apparent eye contact is provided between each local conferee and a displayed image of a corresponding remote conferee.

Abstract: An inexpensive, yet robust color matcher is achieved by an apparatus which includes a compare device coupled to receive, as a first input, an input signal representing a combination of a luminance component Y and a chrominance component, and further coupled to receive as a second input, a threshold T, for comparing the input signal to the threshold T and outputting a color match signal if the input signal falls within a range defined by T and -T; and a threshold supply device coupled to the second input for supplying the threshold T, wherein the threshold T is a function of Y and at least two adjustable parameters.

Abstract: In a robotics system, an image processor may use a moment generator in the identification of an object. Image signals may be provided by an image source such as a TV camera. Synchronizing signals may be extracted from the image signals and together with the image may be used to modify the image signals. Either modified or unmodified image signals may thereafter be processed. Further, the synchronization signals together with moment select signals may be supplied to a moment generator logic array which, in turn, is arranged to provide iterative control signals responsive to which the moment generator may iteratively and recursively generate moments in an orderly, time efficient manner. For example, in one embodiment, p-values (p=x.sup.i y.sup.j) may be iteratively and recursively generated (using stuffing) and combined (using a logic AND) with the image signals a(x,y) being processed to further generate ##EQU1## values, which F.sub.