System and method for sensing a feature of an object in an interactive video display

Embodiments of the present invention include a method for processing captured image information in an interactive video display system. The method includes accessing a region of a vision image. The method further includes comparing the region of the vision image to a first orientation of a value image. The value image comprises a plurality of weighted values representing a feature to be detected. The method further includes comparing the region of the vision image to a second orientation of the value image. The method further includes determining which orientation of the value image best matches the feature to be detected to an object of the region of the vision image.

FIELD OF THE INVENTION

Embodiments of the present invention are related to the field of video image processing. More specifically, embodiments of the present invention relate to automatically identifying features of objects in an interactive video display system.

BACKGROUND OF THE INVENTION

One aspect of image processing includes human-computer interaction by detecting human forms and movements to allow interaction with images. Applications of such processing can use efficient or entertaining ways of interacting with images to define digital shapes or other data, animate objects, create expressive forms, etc.

Detecting the position and movement of a human body is referred to as “motion capture.” With motion capture techniques, mathematical descriptions of a human performer's movements are input to a computer or other processing system. Natural body movements can be used as inputs to the computer to study athletic movement, capture data for later playback or simulation, enhance analysis for medical purposes, etc.

Motion capture techniques tend to be complex. Some techniques require the human actor to wear special suits with high-visibility points at several locations. Other approaches use radio frequency or other types of emitters, multiple sensors and detectors, blue screens, extensive post processing, etc. Techniques that rely on simple visible light image capture are not accurate enough to provide well-defined and precise motion capture.

Some motion capture applications allow an actor, or user, to interact with images that are created and displayed by a computer system. For example, an actor may stand in front of a large video screen projection of several objects. The actor can move, or otherwise generate, modify, and manipulate the objects by using body movements. Different effects based on an actor's movements can be computed by the processing system and displayed on the display screen. For example, the computer system can track a path of the actor in front of the display screen and render an approximation, or artistic interpretation of the path onto the display screen. The images with which the actor interacts can be, e.g., on the floor, wall, or other surface, suspended three-dimensionally in space, displayed on one or more monitors, projection screens or other devices. Any type of display device or technology can be used to present images with which a user can control or interact.

In some applications, such as point of sale, retail advertising, promotions, arcade entertainment sites, etc., it is desirable to capture the motion of an untrained user (e.g., a person passing by) in a very unobtrusive way. Ideally, the user will not need special preparation or training and the system will not use unduly expensive equipment. Also, the method and system used to motion capture the actor should be invisible or undetectable to the user. Many real world applications must work in environments where there are complex and changing background and foreground objects, short capture intervals and other factors that can make motion capture difficult.

SUMMARY OF THE INVENTION

Various embodiments of the present invention, a method and system for detecting a feature of an object in an interactive video display system, are described herein. In one embodiment of the invention, a tip of an object, e.g., a finger, is detected in a vision image. In another embodiment of the invention, a tip of a foot is detected in a vision image. In one embodiment of the invention, a memory stored template image comprising weighted values (e.g., a value image) is compared to pixels of a vision image to determine a feature of an object. In one embodiment of the invention, pixels of the foreground/background classification image (e.g., vision image) are multiplied by the corresponding values (for a particular orientation) of the value image to determine the degree that the object matches the value image. In one embodiment of the invention, multiple orientations of the value image are multiplied by the vision image to determine an orientation of the value image that best matches a feature of an object.

More specifically, embodiments of the present invention include a method for processing captured image information in an interactive video display system. The method includes accessing a region of a vision image. The method further includes comparing the region of the vision image to a first orientation of a value image. The value image comprises a plurality of weighted values representing a feature to be detected. The method further includes comparing the region of the vision image to a second orientation of the value image. The method further includes determining which orientation of the value image best matches the feature to be detected.

Embodiments of the present invention further include a system for processing captured image information in an interactive video display system. The system includes an input for receiving a region of a vision image. The system also includes a comparer for comparing the region of the vision image to a plurality of orientations of a value image. The value image comprises a plurality of weighted values representing a feature of the vision image to be detected. The system further includes a determiner for determining which of the plurality of orientations of the value image best matches the feature to be detected.

Embodiments of the present invention further include a computer usable medium having computer-readable program code embedded therein for causing a computer system to perform a method for processing captured image information in an interactive video display system as described above.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various embodiments of the invention, a system and method for sensing features of objects in an interactive video display system, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it is understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be recognized by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the invention.

It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “sensing” or “comparing” or “multiplying” or “accessing” or “averaging” or “representing” or “transmitting” or “updating” or “identifying” or the like, refer to the action and processes of an electronic system (e.g., projection interactive video display system100ofFIG. 1A), or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the electronic device's registers and memories into other data similarly represented as physical quantities within the electronic device memories or registers or other such information storage, transmission or display devices.

Various embodiments of the present invention in the form of one or more exemplary embodiments will now be described. The described embodiments may be implemented on an interactive video display system including a vision system that captures and processes information relating to a scene. The processed information is used to generate certain visual effects that are then displayed to human users via an interactive display device. Human users are able to interact with such visual effects on a real-time basis.

FIG. 1Aillustrates a projection interactive video display system100in accordance with an embodiment of the present invention. Projection interactive video display system100uses a camera105, a projector110that projects an image120onto the interactive space115of surface102, and a local computer (not shown) that takes as input the image of camera105(e.g., vision image information) and outputs a video image to projector110. Alternatively, a rear projection display screen can be used in lieu of a projector110.

The local computer processes the camera105input to discern on a pixel-by-pixel basis what portions of the volume in front of surface102(e.g., interactive space115) are occupied by people (or moving objects) and what portions of surface102are background e.g., static images. The local computer may accomplish this by developing several evolving models of what the background is believed to look like, and then comparing its concepts of the background to what camera105is currently imaging. Alternatively, components of the local computer that process camera105input are collectively known as the vision system. Various embodiments of projection interactive video display system100and the vision system are described in co-pending U.S. patent application Ser. No. 10/160,217, filed on May 28, 2002, entitled “INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, and in co-pending U.S. Provisional Patent Application No. 60/514,024, filed on Oct. 24, 2003, entitled “METHOD AND SYSTEM FOR PROCESSING CAPTURED IMAGE INFORMATION IN AN INTERACTIVE VIDEO SYSTEM,” by Bell, and assigned to the assignee of the present application, both of which are herein incorporated by reference.

FIG. 1Billustrates a self-contained interactive video display system150in accordance with an embodiment of the present invention. Self-contained interactive video display system150displays an image onto display screen155, and uses a camera (not shown) to detect people and objects in interactive space160. A local computer, also referred to as the image system, takes as input the image of the camera and outputs a video image to display screen155.

Various embodiments of self-contained interactive video display system150are described in co-pending U.S. patent application Ser. No. 10/946,263, filed on Sep. 20, 2004, entitled “SELF-CONTAINED INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell et al., and assigned to the assignee of the present application, co-pending U.S. patent application Ser. No. 10/946,084, filed on Sep. 20, 2004, entitled “SELF-CONTAINED INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, and co-pending U.S. patent application Ser. No. 10/946,414, filed on Sep. 20, 2004, entitled “INTERACTIVE VIDEO WINDOW DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, all of which are herein incorporated by reference. Furthermore, various embodiments of the vision system are described in co-pending U.S. patent application Ser. No. 10/160,217, filed on May 28, 2002, entitled “INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, and in co-pending U.S. Provisional Patent Application No. 60/514,024, filed on Oct. 24, 2003, entitled “METHOD AND SYSTEM FOR PROCESSING CAPTURED IMAGE INFORMATION IN AN INTERACTIVE VIDEO SYSTEM,” by Bell, and assigned to the assignee of the present application, both of which are herein incorporated by reference.

According to one embodiment of the interactive video display system (e.g., projection interactive video display system100ofFIG. 1A), there is an input image from a monochrome camera (e.g., camera105ofFIG. 1A) and a computer vision system that is able to separate foreground objects of interest (e.g., people) from the background of the input image in real time so that the location and outline of the foreground objects can serve as input to an interactive application.

The camera input image (e.g., vision image) is an image representing a real world scene viewed by the camera. This real world scene contains a static background of unknown brightness and appearance as well as various foreground objects that are able to move, such as, people and objects held or moved by people. The camera input image may be manipulated or cropped so that the area viewed by the camera corresponds to the boundaries of a display. Embodiments of the present invention determine a location and direction of a feature of the object in the foreground of the camera image.

The computer vision system outputs a foreground/background distinction (also referred to as a vision image) that corresponds to the camera input image. Each pixel in this image is capable of assuming one of two values: one value for foreground and another value for background. This pixel's value represents whether the vision system determines the pixel with the same position in the camera input image is foreground or background. In one exemplary embodiment, the foreground/background distinction image is an 8-bit grayscale image, with a pixel value of “0” for background and a pixel value of “255” for foreground. In some embodiments, the vision image may have gradated values representing probabilistic foreground/background assessments or other methods of representing vision information. Other implementations may represent foreground/background distinction using different techniques. In each case, the objective of the foreground/background distinction processing for the vision image is to generate a data structure that indicates the position and shape of input objects (e.g., people etc.) with interactive space.

The camera input image may be preprocessed before being input into the vision system. For example, the image may be blurred slightly to reduce noise or gamma corrected to increase or decrease the vision system's sensitivity to dark or light areas. In many cases, the camera input image may be cropped, linearly transformed, or otherwise calibrated. Other well-known ways and/or methods to preprocess the camera input image could also be used. In one embodiment of the invention, the resolution is decreased to save time for processing the image. In addition, if a pixel is determined to not be like the feature being detected, it can usually be assumed that neighboring pixels are not like the feature being detected.

Alternatively, the feature matching system may only be run on pixels that fall on the border between a foreground area and a background area on the vision image. In one embodiment of the invention, the feature being detected is a tip, e.g., a finger tip.

It is appreciated that the term “tip” has been used for illustrative purposes only. It is appreciated that embodiments of the present invention can be used to detect the location and orientation of any feature of foreground objects of an interactive video display system. The foreground object can be a user or any object held or manipulated by a user of the interactive video display system. For example, the feature being detected may be the shape formed by two arms crossing in an “X” shape. Or, the feature may correspond to two user's hands reaching toward each other but not touching. The feature detector can detect any feature of the vision image viewable by the camera.

Embodiments of the present invention determine a tip of an object in the foreground of the vision image to improve user interaction with images displayed by the interactive video display system. Embodiments of the present invention compare the objects of the foreground to template images (e.g., value images) to determine if the object is like the feature represented by the value image. For example, a vision image of an object is compared to a value image comprising weighted regions representing a tip.

In one embodiment of the invention, the foreground object is compared to a plurality of orientations of the value image. The orientation of the value image that is most tip-like can be used to determine the direction of the tip. This further improves user interaction with the displayed objects e.g., menu items, graphical elements, etc.

FIG. 1Cis a data flow diagram of an exemplary system for sensing a feature of an object in an interactive video display system in accordance with embodiments of the present invention. System190includes an input191for receiving the vision image. In one embodiment of the invention, a vision image is split into a plurality of regions and each region is individually examined for a feature to be identified. Embodiments of the present invention search for features in a variety of orientations. For example, several rotated copies of the feature being detected are compared to different locations of the vision image.

System190further includes a comparer192. The portions of the vision image are sent from the input191to the comparer. In one embodiment of the invention, the comparer192compares the portion of the vision image to a plurality of orientations of a value image196.

A determiner193determines which of the plurality of orientations of the value image196best matches an object or feature of the portion of the vision image. Based on the match of the value image, a feature sensor194determines the location of the features detected by the determiner193. The result is output to a graphical user interface195.

FIG. 2is an illustration of a portion of a vision image200in accordance with embodiments of the present invention. As stated above, regions of the vision image that are determined to be background210are assigned a value of zero (e.g., “off”) and regions of the vision image that are determined to comprise foreground objects220of interest (e.g., people or other objects) are assigned a positive value (e.g., 225).

It is appreciated that the values of zero and 225 are arbitrary and could be any values, however, in accordance with embodiments of the invention, background areas are set to a value of zero and foreground areas are set to a positive value. It is also appreciated that background regions210of the vision image200are considered “off” regions and objects220in the foreground are considered “on” regions. A perimeter225is defined as the boundary between on region220and off region210. In one embodiment of the invention, the perimeter225is the width of a single pixel.

FIG. 3Ais an illustration of an exemplary value image300e.g., bitmapped image in accordance with embodiments of the present invention. A value image300can be created for a desired shape or feature of an object that is to be identified from the vision image200ofFIG. 2. Value image300ofFIG. 3Ais for a tip. The parts of the value image300that are most tip-like are assigned the highest weighted value. It is appreciated that a value image can be created for object attributes such as curvature of particular features, distance from a center point, etc.

In one embodiment of the invention, a tip can be the tip of a finger, the tip of a foot or the tip of any object in the vision image. It is appreciated that in most cases, a user interacts with displayed objects with the tip of an object. In most cases, the user may use the tip of a finger or the tip of a foot (or shoe) to interact with the displayed objects. However, it is appreciated that the tip could be of any object used to interact with the displayed images.

It is also appreciated that locating the tip of an object improves recognition of user gestures in which tip movement may define the gesture. For example, in the case of an interactive video game, user gestures can be used to control and interact with the video game. Improved recognition of user gestures enhances the user's experience with the interactive video game.

The value image300includes a plurality of regions320,321,323,324comprising weighted values (e.g., 20, 10, 0 and −10) around a center point310. The weighted regions of the value image that best match the desired shape (e.g., the desired shape that is being matched) have a higher value (e.g., region320has a value of 20) than the regions outside the desired shape (e.g., region324has a value of zero). In one embodiment of the invention, regions closest to the center point310are assigned higher weighted values. Region323has a value of negative ten.

In one embodiment of the invention, individual frames of the vision image are multiplied pixel by pixel by the corresponding value of the value image (for a particular orientation) and a result is determined. In one embodiment of the invention, the average value of the value image is equal to zero. In one embodiment of the invention tip-like features are identified over features that are not tip-like based on a threshold result of the multiplication. In one embodiment of the invention, if the average value of the result of the multiplication is greater than the selected threshold value, the image is determined to be a match of the value image. If the resulting value is less than the threshold value, the image is determined to not be a match of the value image (for a particular orientation).

In one embodiment of the invention, each pixel of the vision image is multiplied by the corresponding weighted value of the value image. In one embodiment of the invention, only the pixels on the perimeter of an “on” region of the vision image are multiplied by the corresponding values of the value image.

In one embodiment of the invention, at each pixel of the vision image, several different orientations of the value image are compared to the region surrounding the pixel. The “best fit” is the one with the highest value as computed by multiplying the vision image's region with the value image. If the value for the “best fit” is above the threshold value for tips, it is classified as a tip. If it is lower than the threshold value, it is not classified as a tip. In some cases, multiple tips are detected very close together (e.g., only a few pixels apart). In these cases, embodiments of the present invention may apply a tip thinning technique so that only one tip is recognized per arm or leg, for example. This can be performed many different ways. In one embodiment of the invention, tips that have another tip of a higher value (as computed by the value image multiplication) that is closer to it than a distance of N pixels are deleted.

In one embodiment of the invention, the vision image is multiplied by the value image in a plurality of orientations to determine an orientation of the value image that best matches the shape of the vision image to be identified. In one embodiment of the invention, the value image is compared to the vision image in sixteen different orientations in clockwise fashion across sixteen different rotational offsets. In one embodiment of the invention, the pixels on the perimeter of the vision image are multiplied by a plurality of orientations of the value image to determine the direction of the tip. The orientation that results in the highest value is determined to be the direction of the tip (assuming a tip exists at that location).

FIG. 3Bis an illustration of how a value image is compared to a vision image370in multiple orientations, orientation A380and orientation B390. In one embodiment of the invention, orientation A is compared to the vision image370by scanning the value image back and forth across the image370in a plurality of orientations. In one embodiment of the invention, orientation B390is compared sequentially after orientation A380for the same portion of the vision image370. In one embodiment of the invention, pixels on the perimeter of a foreground object are scanned and compared to multiple orientations of the value image.

It is appreciated that the way in which the value image is scanned over the vision image can be one of many methods used for comparing images well known in the art. It is also appreciated thatFIG. 3Bshows only two orientations of the value image and that any number of orientations of the value image can be used to sense a feature in accordance with embodiments of the present invention.

FIG. 4is an illustration of the result400of multiplying the vision image200ofFIG. 2by the value image300ofFIG. 3in accordance with embodiments of the present invention. The areas of the vision image200that are “off” (e.g., area210) are set to a value of zero. The areas that are “on” (e.g., area225) are set to the corresponding weighted value of the value image. For example, region420ofFIG. 4has a value of twenty and region410has a value of ten.

As stated above, the value image can be weighted such that the average value of the value image is, for example, zero. In one embodiment of the invention, a threshold value for the result of multiplying the value image by the vision image is set (e.g., a threshold value of one). Resulting values of the multiplication that are greater than the threshold value are considered tip-like and resulting values of the multiplication that are less than the threshold value are not considered tip-like. For example, the average value of the result400ofFIG. 4is 1.5. In this case, assuming a threshold value of one, the result400is considered tip-like. However, referring now toFIG. 5B, the result500bhas an average value of 0.5, which is below the threshold value of one. In this case, the result500bwould not be considered tip-like.

FIG. 5Ais an illustration of a vision image500aof an elbow501.FIG. 5Bis an illustration of the result500bof multiplying the vision image500aof the elbow501by the value image300ofFIG. 3. The result500bcomprises a large area520that has a negative value and regions505and506that comprise positive values. The large region with a negative value lowers the average value and the result500b. As a result, the average value of the result500bis lower than the threshold value of one and the image is determined to not be tip-like.

In one embodiment of the invention, only the pixels on the perimeter of a foreground area are considered. In this embodiment of the invention, each pixel of the perimeter is compared to a plurality of orientations of the value image. The most positive result is assigned to the pixel and the pixel on the perimeter with the highest value is considered the tip (assuming this value exceeds the threshold value, e.g., threshold value of 0.5).

FIG. 6is an illustration of a foreground object perimeter620of a value image600in accordance with embodiments of the present invention. The pixels on the perimeter620have been evaluated by a plurality of orientations of a value image. In this example, the highest resulting value is assigned to each pixel. For clarity only a few of many values are illustrated. Pixel631has a value of three, pixel632has a value of negative five, pixel633has a value of negative seven, pixel634has a value of negative one, pixel635has a value of four and pixel636has a value of negative two.

Multiple tips may be chosen for a single foreground area if they are far enough away from each other. Or, no tips may be chosen. InFIG. 6, both pixel631and pixel635may be chosen as tips because they exceed the threshold value of zero.

In one embodiment of the invention, locating a tip of an object improves user interaction with the interactive video display system. For example, determining a tip of an object improves recognizing user gestures. This becomes important in interactive games. Recognized user gestures can be used as user input for controlling an interactive game. A movement path of the tip of an object can define a gesture. In one embodiment of the invention, a user tip is interactive with a button, icon or other menu items displayed by the interactive video display system.

It is appreciated that embodiments of the present invention can be used for identifying salient features of an interactive video projection system. For example, assume an interactive baseball game wherein a user physically holds a baseball and makes motions with the baseball to interact with projected images. Embodiments of the present invention can determine the position and orientation of the baseball to improve the user experience with the interactive game. In this embodiment of the invention, the value image comprises weighted regions that facilitate recognition of a baseball rather than a tip.

In another embodiment embodiments of the present invention can be used to make a gesture game in which the player can make different types of gestures (e.g., a pointing index finger, an “ok” sign, cupping hands together to form a “C”, crossing arms to form an “X,” etc.) to affect the game state. For example, the user could be in a fighting game where they make one gesture to shoot and another to block.

In another embodiment of the invention, persistent attributes of a foreground image are used to identify features. For example, specific curvatures (e.g., small radius curves) of objects can indicate a tip. In another embodiment of the invention, the point furthest from a center point of an object is determined to be the tip of the object. In this embodiment of the invention, the end of an extended leg or arm is determined to be the tip.

FIG. 7is a flow diagram of an exemplary computer controlled method700for processing vision image information in an interactive video display system in accordance with embodiments of the present invention.

At step702, method700includes accessing a region of a vision image, e.g., digital image. In one embodiment of the invention, the vision image comprises background regions and foreground regions. In one embodiment of the invention, the foreground regions comprise a user of an interactive video display system.

At step704, method700includes comparing a portion of the region of the vision image to a first orientation of a value image, wherein the value image comprises a plurality of weighted values representing a feature to be detected. In one embodiment of the invention, the value image represents a feature used to interact with the interactive video display system. For example, the value image can represent human features such as a tip of a finger, a tip of a foot or shoe or the value image can represent other objects such as a baseball, hokey stick, fishing rod or any other object used to interact with displayed objects of the interactive video display system.

In one embodiment of the invention, only pixels on a perimeter of a foreground object are examined. In this embodiment of the invention, zero or more pixels on the perimeter may be considered tip-like.

At step706, method700includes comparing the portion of the vision image to a second orientation of the value image. In one embodiment of the invention, the direction of the tip is determined. In one embodiment of the invention, multiple orientations of the value image are compared to the portion of the vision image and the orientation that results in the highest value is used to determine the direction of the tip. Other techniques may be used, for example, multiple orientations with high values may be averaged.

At step708, method700includes determining which orientation of the value image best matches said feature to be detected. The value image orientation that has the highest average resulting value when the value image and vision image are multiplied together is considered the most tip-like direction. The above is repeated for multiple different portions of the image in order to locate the best match.

FIG. 8is a flow diagram of an exemplary method for sensing a feature of an object in an interactive video display system in accordance with embodiments of the present invention. In one embodiment of the invention, the feature is a tip.

At step802, method800includes accessing a region of a vision image. In one embodiment of the invention, background regions of the vision image are considered “off” regions and foreground objects of the vision image are considered “on” regions. In one embodiment of the invention, on regions are assigned a higher value than off regions for purposes of detecting features in accordance with embodiments of the present invention.

At step804, method800includes multiplying pixels of the region of the vision image by weighted values of a value image. In one embodiment of the invention, all pixels in the “on” regions are evaluated. In other embodiments of the invention, a subset, random or ordered, of the pixels in the “on” regions are evaluated. In another embodiment of the invention, only pixels on a perimeter of the “on” region are evaluated.

At step806, method800includes determining an average value of the pixels after the multiplying of step804. In one embodiment of the invention, the average value of the pixels is used to determine how well the region matches the value image.

At step808, method800includes comparing the average value of the pixels to a feature threshold value wherein average values greater than the feature threshold value indicate a match between the region of the vision image and the value image.

At step810, method800includes doing the next region. In one embodiment of the invention, the entire vision image is scanned in a fashion described in conjunction withFIG. 3B.

Referring now toFIG. 9, a block diagram of exemplary computer system900is shown. It is appreciated that computer system900ofFIG. 9described herein illustrates an exemplary configuration of an operational platform upon which embodiments of the present invention can be implemented. Nevertheless, other computer systems with differing configurations can also be used in place of computer system900within the scope of the present invention. For example, computer system900could be a server system, the client system, a node on a network, a personal computer, a game console or an embedded computer system. Furthermore, computer system900could be a multiprocessor computer system.

Computer system900includes an address/data bus901for communicating information, a central processor902coupled with bus901for processing information and instructions, a volatile memory unit903(e.g., random access memory, static RAM, dynamic RAM, etc.) coupled with bus901for storing information and instructions for central processor902and a non-volatile memory unit904(e.g., read only memory, programmable ROM, flash memory, EPROM, EEPROM, etc.) coupled with bus901for storing static information and instructions for processor902. Computer system900may also contain a display device906coupled to bus901for displaying information to the computer user. In one embodiment of the invention, display device906is a video display projector. Moreover, computer system900also includes a data storage device905(e.g., disk drive) for storing information and instructions.

Also included in computer system900ofFIG. 9is an optional alphanumeric input device907. Device907can communicate information and command selections to central processor902. Computer system900also includes an optional cursor control or directing device908coupled to bus901for communicating user input information and command selections to central processor902. Computer system900also includes signal communication interface909, which is also coupled to bus901, and can be a serial port. Communication interface909can also include number of wireless communication mechanisms such as infrared or a Bluetooth protocol.

Embodiments of the present invention, a system and method for sensing a feature of an object in an interactive video display system have been described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the following Claims.