Abstract:
A view morphing algorithm is applied to synchronous collections of video images from at least two video imaging devices, and interpolating between the images, creates a composite image view of the local participant. This composite image approximates what might be seen from a point between the video imaging devices, presenting the image to other video session participants.

Description:
This application is a Continuation of U.S. patent application Ser. No. 09/995,272, filed on Nov. 27, 2001, now U.S. Pat. No. 6,724,417, which claims priority to Provisional Application Ser. No. 60/250,955, filed on Nov. 29, 2000. 
    
    
     TECHNICAL FIELD 
     This invention relates to the field of video conferencing and in particular to methods and systems maintaining the appearance of eye contact between communicants in a teleconference. 
     BACKGROUND ART 
     A primary concern with video teleconferencing systems is the frequent lack of eye contact between participants. In the most common configuration, each participant uses a computer monitor on which an image of the second participant is displayed, while a camera mounted above the monitor captures the image of the local participant for display on the monitor of the second participant. Since participants frequently look at the monitor, either at the image of the second participant or elsewhere on the display, rather than directly at the video camera, there is the appearance that the participants are not looking at one another, resulting in an unsatisfactory user experience. 
     Many prior art solutions to the eye contact problem have incorporated half-silvered, partially transmissive and partially reflective mirrors, or beamsplitters. These solutions have typically incorporated a beamsplitter placed in front of a computer display at a 45 degree angle. In one typical configuration, a video camera, located behind the beamsplitter, captures an image of the local participant through the beamsplitter. The local participant views an image of the second participant on the display as reflected by the beamsplitter. 
     In devices incorporating a conventional CRT, the resulting device is both aesthetically bulky and physically cumbersome. Furthermore, in cases involving an upward facing display, the display is viewable both directly and as reflected by the beamsplitter, greatly distracting the local participant. To alleviate this problem, prior solutions, including those described in U.S. Pat. Nos. 5,117,285 and 5,612,734 have introduced complicated systems involving polarizers or micro-louvers to obstruct a direct view of the upward facing display by the local participant. In all cases, the image of the second participant appears recessed within the housing holding the display, beamsplitter, and video camera. The resulting distant appearance of the second participant greatly diminishes the sense of intimacy sought during videoconferencing. 
     Another series of prior art attempts to alleviate this problem through the use of computational algorithms that manipulate the transmitted or received video image. For example, U.S. Pat. No. 5,500,671 describes a system that addresses the eye contact problem by creating an intermediate three-dimensional model of the participant based on images captured by two imaging devices on either side of the local display. Using this model, the system repositions artificially generated eyes at an appropriate position within the image of the local participant transmitted to the second participant. The resulting image, with artificially generated eyes and a slight but frequent mismatch between the position of the eyes relative to the head and body of the participant, is unnatural in appearance. Furthermore, the creation of an intermediate three-dimensional model is computationally intensive, making it difficult to implement in practice. 
     U.S. Pat. No. 5,359,362 describes a system “using at each station of a video conferencing system at least a pair of cameras, neither of which is on the same optical axis as the local monitor, to obtain a three-dimensional description of the speaker and from this description obtaining for reproduction by the remote monitor at, the listener&#39;s station a virtual image corresponding to the view along the optical axis of the camera at the speaker&#39;s station. The partial 3D description at the scene can be used to construct an image of the scene from various desired viewpoints. The three dimensional description is most simply obtained by viewing the scene of interest, by a pair of cameras, typically preferably aligned symmetrically on either left and right or above and below, about the optical axis of the monitor, solving the stereo correspondence problem, and then producing the desired two dimensional description of the virtual image for use by the monitor at the listener&#39;s station.
         (The) process of creating the desired two-dimensional description for use as the virtual image consists of four steps, calibration, stereo matching, reconstruction and interpolation. The calibration converts the view from two tilted cameras into two parallel views important for stereo matching. The stereo matching step matches features, such as pixels, between the two views to obtain a displacement map that provides information on the changes needed to be made in one of the observed views. The reconstruction step constructs the desired virtual view along the axis between the two cameras from the displacement map and an observed view, thereby recovering eye contact. The final step is to fill in by interpolation areas where complete reconstruction is difficult because of gaps in the desired virtual view that result from limitations in the displacement map that was formed.”       

     Note that U.S. Pat. No. 5,359,362 generates its virtual image by transforming the image obtained by one of the two physical imaging devices. The resulting image does not reflect any features of the local participant that are occluded from the transformed image. 
     Still other prior art approaches construct a complete mathematical model of the local participant and his nearby surroundings. This mathematical model is then transmitted to the second participant, where it is reconstructed in a manner providing eye contact. Clearly, such systems require that both the remote and local communicants own and operate the same videoconferencing device. This presents a significant obstacle to introduction and widespread adoption of the device. 
     Consider the prior art as found in U.S. Pat. No. 5,359,632 again. Often, in such stereo matching systems, prior to beginning real-time video conferencing image processing, a calibration operation is used to obtain information describing the positioning and optical properties of the imaging devices. First a camera projection matrix is determined for each of the imaging devices. This camera projection matrix characterizes the correspondence of a point in three-dimensional space to a point in the projective plane imaged by the video camera. The matrix determined is dependent on the position and angular alignment of the camera as well as the radial distortion and zoom factor of the camera lens. One prior art approach employs test patterns and a camera calibration toolbox developed by Jean-Yves Bouguet at the California Institute of Technology. This calibration toolbox draws upon methods described in the papers entitled “Flexible Camera Calibration by Viewing a Plane from Unknown Orientations” by Zhang, “A Four-step Camera Calibration Procedure with Implicit Image Correction” by Heikkila and Silven, “On Plane-Based Camera Calibration: A General Algorithm, Singularities, Applications” by Sturm, and “A versatile camera calibration technique for high accuracy 3D machine vision metrology using off-the-shelf TV cameras and lenses” by R. Y. Tsa and Maybank. 
     Following the determination of these camera projection matrices, a two dimensional rectifying transform is determined for each of the pair of imaging devices. The transformation may be determined based on the previously determined camera projection matrices, using an approach described in the paper of Fusiello, Trucco, and Verri entitled “Rectification with unconstrained stereo geometry”. The transformation, when applied to a pair of images obtained from the imaging devices, produces a pair of rectified images. In such a set of images, each pixel in a first video camera image corresponds to a pixel in the second image located along a line at the same vertical location as the pixel in the first image. 
     The prior art also includes calculating a dense correspondence between the two generated camera images. Several algorithms are available for determining such a dense correspondence including the method described in the paper of Georges M. Quenot entitled “The ‘Orthogonal Algorithm’ for Optical Flow Detection Using Dynamic Programming”. The Abstract states “This paper introduces a new and original algorithm for optical flow detection. It is based on an iterative search for a displacement field that minimizes the L 1  or L 2  distance between two images. Both images are sliced into parallel and overlapping strips. Corresponding strips are aligned using dynamic programming exactly as 2D representations of speech signal are with the DTW algorithm. Two passes are performed using orthogonal slicing directions. This process is iterated in a pyramidal fashion by reducing the spacing and width of the strips. This algorithm provides a very high quality matching for calibrated patterns as well as for human visual sensation. The results appears to be at least as good as those obtained with classical optical flow detection methods.” 
     What is needed is a method for efficient real-time processing of at least two spatially offset image sequences to create a virtual image sequence providing a sense of eye contact, which is of great value in a number of applications including, but not limited to, video conferencing. The sense of eye contact should operate effectively across the full range of local participant head positions and gaze directions. It must provide a natural view of the local participant for the second participant. It must be aesthetically pleasing and easily operated by a typical user. What is further needed is apparatus efficiently interfacing to a standard video conferencing system and providing the advantages of such methods of generating virtual image sequences. 
     SUMMARY OF THE INVENTION 
     To resolve the identified problems found in the prior art, the present invention creates a head-on view of a local participant, thereby enhancing the sense of eye contact provided during any of the following: a video conference session, a video phone session, a session at a video kiosk, and a video training session. Note that video conference sessions include, but are not limited to, sessions presented via one or more private communications channels and sessions presented via one or more broadcast channels. 
     A view morphing algorithm is applied to a synchronous collection of images from at least two video imaging devices. These images are interpolated to create interpolation images for each of the video imaging devices. The interpolated images from at least two of the video imaging devices are combined to create a composite image of the local participant. This composite image approximates a head-on view of the local participant providing excellent eye contact. 
     It should be noted that the synchronous image collection is comprised of images received at approximately the same time. 
     It is often preferred to interpolate the images to a point between the video imaging devices when they are placed in a radially symmetric manner about the local participant. It may be preferred, when the video imaging devices are not placed in a radially symmetric relationship with the local participant, that a more complex mechanism potentially involving partial extrapolation may be used to create what is identified herein as the interpolated images. 
     The video imaging devices are preferably placed on opposite sides of a local display and the composite image further approximates essentially what might be seen from the center of that local display. 
     This head-on view of the local participant supports the local participant looking directly at the monitor and provides a sense of eye contact when viewed by the second participant, actively aiding the sense of personal interaction for all participants. 
     Certain embodiments of the invention include, but are not limited to, various schemes supporting generation of the composite image, control of composite image generation by at least one of the second participants, and adaptively modifying the current images at certain stages based upon remembered displacements from previous images. These embodiments individually and collectively aid in improving the perceived quality of eye contact. 
     Aspects of the invention include, but are not limited to, devices implementing the methods of this invention in at least one of the following forms: dedicated execution engines, with or without instruction processing mechanisms; mechanisms involving table lookup of various non-linear functions; and at least one instruction processing computer performing at least some of the steps of the methods as program steps residing within memory accessibly coupled with the computer. 
     These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a simplified block diagram overview of the invention, including local participant  10 , video display  30 , pair of imaging devices  41  and  42 , means for generating composite image  100 , motion video portal  70 , video delivery system  80  and second participant  90 ; 
         FIG. 1B  shows a simplified block diagram of an alternative embodiment of the invention to  FIG. 1A , with motion video portal  70  including first computer  200  with a program system  1000  at least in part generating composite image  146 ; 
         FIG. 2  shows a diagram of the preferred positioning of imaging devices  41  and  42  relative to local participant  10  as found in  FIGS. 1A and 1B ; 
         FIG. 3A  depicts a detail flowchart of first program system  1000  of  FIG. 1B  implementing a method of conveying eye contact of a local participant presented to at least one second participant in a video delivery session as a motion video stream based upon observations by an imaging device collection; 
         FIG. 3B  depicts a detail flowchart of operation  1022  of  FIG. 3A  for calculating the dense correspondence; 
         FIG. 4A  depicts a detail flowchart of operation  1032  of  FIG. 3  for generating the interpolated image, for each of the pixels of the interpolated image; 
         FIG. 4B  depicts a detail flowchart of operation  1042  of  FIG. 3  for combining the interpolated images is further comprised, for each of the pixels of the composite image; 
         FIG. 4C  depicts a detail flowchart of operation  1042  of  FIG. 3  for combining corresponding pixels; 
         FIG. 5A  depicts a detail flowchart of operation  1112  of  FIG. 4C  for combining corresponding pixels; 
         FIG. 5B  depicts a detail flowchart of operation  1132  of  FIG. 5A  for predominantly combining the corresponding pixel of the first interpolated image whenever the composite image pixel is a member of the first side collection; 
         FIG. 6A  depicts a detail flowchart of operation  1142  of  FIG. 5A  for predominantly combining the corresponding pixel of the second interpolated image whenever the composite image pixel is a member of the second side collection; 
         FIG. 6B  depicts a detail flowchart of operation  1152  of  FIG. 5A  for mixedly combining the corresponding pixels of the at least two interpolated images whenever the composite image pixel is a member of the center collection; 
         FIG. 7  depicts a detail flowchart of operation  1176  of  FIG. 5B  for predominantly combining the corresponding first interpolated image pixel; 
         FIG. 8  depicts a detail flowchart of operation  1196  of  FIG. 6A  for predominantly combining the corresponding second interpolated image pixel; 
         FIG. 9A  depicts a detail flowchart of operation  1216  of  FIG. 6B  for mixedly combining the corresponding pixel of the at least two interpolated images; 
         FIG. 9B  depicts a detail flowchart of operation  1412  of  FIG. 9A  for calculating the blending linear combination; 
         FIG. 10A  depicts a detail flowchart of operation  1462  of  FIG. 9B  for calculating the bulging scale linear combination; 
         FIG. 10B  depicts a detail flowchart of operation  1012  of  FIG. 3  for obtaining the digital version of the image from imaging device collection member as the image member in the synchronized image collection, for each of the imaging device collection members; 
         FIG. 11A  depicts a detail flowchart of method of operation and program system  1000  of  FIGS. 1B and 3  for generating the composite image, for at least two of the imaging device collection members; 
         FIG. 11B  depicts a detail flowchart of operation  1012  of  FIGS. 1B and 3  for obtaining the digital version of the image, for each of the at least two imaging device collection members; 
         FIG. 11C  depicts a detail flowchart of operation  152  of  FIG. 11B  for warping the image digital version; 
         FIG. 12A  depicts a detail flowchart of operation  1572  of  FIG. 11C  for attenuating the displacement factor for the imaging device collection member to modify the displacement factor; 
         FIG. 12B  depicts a detail flowchart of operation  1592  of  FIG. 12A  for multiplying the displacement factor for the imaging device collection member comprised of an operational member of this flowchart; 
         FIG. 13A  depicts a detail flowchart of operational method and/or program system  1000  of  FIGS. 1B and 3  for generating the composite image; 
         FIG. 13B  depicts various imaging device collection member placements in potential relationship with display  30 ; 
         FIG. 14A  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3  for generating the composite image; 
         FIG. 14B  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3  for generating the composite image, for at least two of the imaging device collection members; 
         FIG. 14C  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3  for generating the composite image; 
         FIG. 15A  depicts a detail flowchart of operation  1872  of  FIG. 14C  for specifying the point P; and 
         FIG. 15B  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3 A for generating the composite image. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1A  shows a simplified block diagram overview of the invention, including local participant  10 , video display  30 , pair of imaging devices  41  and  42 , means for generating composite image  100 , motion video portal  70 , video delivery system  80  and second participant  90 . 
     Means  100  for generating composite image  146  is communicatively coupled  114  and  112  with at least two imaging device collection members  41  and  42 , respectively. Means  100  regularly receives an image  118  and  116  from each of the at least two imaging device collection members  41  and  42 , respectively, to provide a synchronized collection of images based upon observations of at least the local participant&#39;s head  10  by the imaging devices. 
     Means  100  for generating composite image  146  is communicatively coupled  142  to motion video portal  70 , providing a succession of composite images  146 , each based upon at least synchronized image collection  116  and  118  to  72  video delivery system  80 . 
     Video delivery system  80  presents  82  second participant  90  motion video stream  72  generated by motion video portal  70  conveying eye contact based upon the succession of composite images  146 . Note that the motion video stream is compatible with a digital motion format and/or an analog motion format. The digital motion format includes, for example, any of the following: MPEG1 format, MPEG2 format, MPEG4 format, H.261 format and H.263 format. The analog format includes, for example, any of the following: NTSC format, PAL format, and SECAM format. 
     A primary responsibility of video delivery system  80  is to initiate and maintain a video delivery session with at least one remote location. Note that in various embodiments of the invention, the video delivery session may include, but is not limited to, any of the following: a video conference session involving at least local participant  10  and at least one second participant  80 , a video phone session involving local participant  10  and second participant  80 , a video kiosk supporting video communication between at least local participant  10  and at least one second participant  80 , video training between at least local participant  10  and at least one second participant  80 , and television broadcast conveying a documentary style interview. Each of these video delivery sessions is based upon the motion video stream presented  72  to the video delivery system  80  from motion video portal  70 . 
     Video delivery system  80  connects  82  to second participant  90 . The connection  82  can include transport across at least one communications network. While not shown, there is typically another motion video stream from second participant  90  which is transported via  82  through video delivery system  80  and rendered for presentation on video display  30 . 
     Additionally, certain embodiments of the invention may offer an ability to view the composite image  146  obtained from means  100  on the local video display  30 . There may further be the ability to view digital versions of the images  118  and  116  obtained from the video imaging devices  41  and  42 . 
     A number of existing technologies are suitable for use as video display  30  including, for example, cathode ray tube monitors, liquid crystal displays, and plasma screen televisions. The display is preferably compatible with the format of the video output signal provided by the video delivery system. 
     Note that in certain embodiments of the invention, means  100  may be at least part of an instruction-processing computer and/or a dedicated hardware accelerator. 
     Note that as used herein, an instruction-processing computer includes, but is not limited to, single instruction and multiple instruction processing mechanisms acting upon single datapaths and multiple datapaths, leading to the often used acronyms of SISD, SIMD, MISD, and MIMD computers. 
     The instructions processed by instruction processing mechanisms include, but are not limited to, instructions which are directly executed to alter the state of the system they control, as well as instructions which alter by inference the state of the system they control. Note that instruction execution may be hardwired into the instruction processor, or interpreted. Inferential systems include, but are not limited to, artificial neural networks, logic programming systems, and content addressable memory driven control systems. 
     As used herein, a dedicated hardware accelerator provides at least one means by which calculations upon picture entities, preferably at least pixel components, may be performed. A dedicated hardware accelerator may or may not include an instruction processing control mechanism. 
     By way of example, a hardware accelerator may include a state machine controller operating at least one partition of its controls as a ones-hot state machine. It may be a collection of state machines, with at least one, some or all of these state machines not having an instruction register. Examples of such state machines often include, but are not limited to, floating point calculators, FIFOs, and bit packing circuits such as Huffman coders and decoders. 
     Local participant  10  of the video delivery session is observed by at least a pair of video imaging devices  41  and  42 . The imaging device collection members  41  and  42  are collectively disposed to reveal essential features, for example, the head of local participant  10  for observation by at least one of imaging device collection members  41  and  42 . 
     Note that each of the digital versions of images  118  and  116  is comprised of a two-dimensional array of pixels of approximately the same size and shape. For the sake of discussion, video imaging device  41  is the first imaging device and video imaging device  42  is the second imaging device. 
     Means  100  is comprised of the following: 
     Means  110  for obtaining a digital version of the image  118  and  116  from each of at least two imaging device collection members  41  and  42 , respectively, as the image member in the synchronized image collection. 
     One embodiment of the invention comprises means  120  for calculating a dense correspondence to determine a displacement in at least a first dimension for each of the pixels in the first image digital version  116  to move each of the pixels to a most nearly corresponding pixel in the image digital versions of at least one other member of the imaging device collection  118 . 
     Means  130  for generating an interpolated image  136  and  138 , for each of the imaging device collection members  41  and  42 , respectively. The interpolated images  136  and  138  are comprised of a two dimensional array of pixels of approximately the same size and shape. 
     Means  140  for combining at least two of the interpolated images  136  and  138  employs a partitioned averaging scheme using at least a second dimension to create the composite image  146 . 
     Note that the definition of first dimension and second dimension as used herein is discussed with respect to  FIG. 13B . 
     The pixels may use, for example, any of the known encoding schemes for designating at least chrominance and luminance, including but not limited to, YUV, RGB, and the various CIE derived pixel coding schemes such as described in the background of the invention. Note that some but not all embodiments of the invention may require conversion between two or more encoding schemes. 
     Conversion between these coding schemes may be performed, for example, by any of the following mechanisms: table look up, numeric calculation and/or compiled logic structures further including but not limited to finite state machines, logic equations, and truth tables. Note that a table look up of a 24 bit pixel value input generating a 24 bit pixel value output requires 48 megabytes of memory. 
       FIG. 1B  shows a simplified block diagram of an alternative embodiment of the invention to  FIG. 1A , with motion video portal  70  including first computer  200  with a program system  1000  at least in part generating composite image  146 . 
     Program system  1000  is comprised of program steps residing in memory  210  accessibly coupled  212  to first computer  200 . 
     Note that the invention includes an apparatus receiving the image collection  136  and  138  that may be stored in a memory, such as memory  210 . The invention may further include various means for obtaining at least one of images  136  and  138   
     Note that means  110  for obtaining the digital version from at least one of the imaging device collection members may include any of the following:
         A frame grabbing circuit  220  coupled  112  to imaging device collection member  42  for obtaining the image  116  from the imaging device as the image member in the synchronized image collection  118  and  116 .   Video interface  240  coupling  114  imaging device collection member  41  to motion video portal  70  for obtaining a digital version of image  118  from imaging device collection member  41 .       

     Obtaining a digital version of an image may also include the step of performing a rectifying transformation. 
     Note that it is preferred with today&#39;s technology that a consistent interface be provided for at least pairs of video imaging devices. It is contemplated that one of the two alternatives discussed in  FIG. 1B  would be used for at least pairs of video imaging devices. 
     The motion video portal  70  may further include any of the following: A first finite state machine  230  receiving digital version of image  118  from imaging device collection member  41  by operating  232  video interface  240 . A first computer  200  coupled (not shown) with video interface  240  and accessibly coupled  212  to a first memory  210  and controlled by first program system  1000  comprised of at least one program step residing in the first memory  210 . 
       FIG. 2  is a diagram showing the preferred positioning of imaging devices  41  and  42  relative to local participant  10 , as found in  FIGS. 1A and 1B . 
     Imaging devices  41  and  42  are positioned at a common radial displacement R from the point of intersection C of the video camera field of view centerlines. The angular separation of the imaging devices, θ, is preferably the smallest allowable separation given the size of video display  30  (not shown) and the housing size of imaging devices  41  and  42 . 
     Imaging devices  41  and  42 , as well as intersection point C of the centerlines, lie approximately in a horizontal plane. Local participant  10  is preferably positioned such that his facial features are approximately located at C. 
     Means  100  receives the video signals from imaging devices  41  and  42 , respectively, and from these video signals, creates an image of local participant  10  as viewed from a point P along the arc common arc A about the point C. 
     To maximize compatibility with existing video delivery equipment, means  100  may receive video input from the imaging devices and provide video output to the video delivery system in any one of a variety of video formats via a variety of transmission protocols. These video formats include but are not limited to analog formats and digital formats. The digital formats may include but are not limited to any of bitmap, grayscale, RGB, DV, YUV, and HDTV. The analog formats may include, but are not limited to, any of RS170, RS343, NTSC, PAL, SECAM, and HDTV. 
     As used herein, the term digital refers to any communications protocol or format based upon ordered collections of digits. Each digit is preferably a member of a single digit value collection containing finitely many digit values. In today&#39;s technology, the preferred digital value collection has two members, usually denoted as ‘0’ and ‘1’. 
     Digital formats are particularly convenient because they allow for simple conversion of image data into a form easily manipulated by the image processing algorithm. If a digital format is selected, a transfer protocol, such as USB or IEEE 1394, may be employed. The particular format of the video output signal is typically selected to match the format of an existing video camera within the local participant&#39;s video delivery setup, thereby ensuring compatibility with the existing video delivery system  20 . 
     With the invention configured as described above, local participant  10  positions himself or herself relative to local display  30  and imaging devices  41  and  42  approximately as shown in  FIG. 2 . 
     Local participant  10  may check his positioning relative to imaging devices  41  and  42  by previewing a composite image on local display  30 . Local participant  10  may then initiate a video delivery session or join an existing video delivery session as provided by video delivery system  80 . After the videoconference, local participant  10  closes the video delivery session as provided by video delivery system  80 . 
     Prior to beginning the image processing operation, a calibration operation is preferably performed to obtain information describing the positioning and optical properties of the two imaging devices. The calibration process may be performed upon assembly of the teleconferencing apparatus if the video camera setup is a permanent fixture, or may be performed each time a change is made to the physical geometry or optical settings of the imaging devices. 
       FIG. 3A  depicts a detail flowchart of first program system  1000  of  FIG. 1B  implementing a method of conveying eye contact of a local participant presented to at least one second participant in a video delivery session as a motion video stream based upon observations by an imaging device collection. 
     Arrow  1010  directs the flow of execution from starting operation  1000  to operation  1012 . Operation  1012  performs obtaining a digital version of the image from each of the members of the imaging device collection as the image member in the synchronized image collection. Arrow  1014  directs execution from operation  1012  to operation  1016 . Operation  1016  terminates the operations of this flowchart. 
     Certain embodiments of the invention include the following operations without operation  1012 . 
     Arrow  1020  directs the flow of execution from starting operation  1000  to operation  1022 . Operation  1022  performs calculating at least one dense correspondence to determine a displacement in at least a first dimension for each of the pixels in the first image digital version that would move each of the pixels to a most nearly corresponding pixel in the image digital version of at least one other member of the imaging device collection. Arrow  1024  directs execution from operation  1022  to operation  1016 . Operation  1016  terminates the operations of this flowchart. 
     Arrow  1030  directs the flow of execution from starting operation  1000  to operation  1032 . Operation  1032  performs generating an interpolated image for at least two of the imaging device collection members from the at least one dense correspondence of the at least two images. Arrow  1034  directs execution from operation  1032  to operation  1016 . Operation  1016  terminates the operations of this flowchart. 
     Each of the interpolated images is comprised of a two-dimensional array of pixels of approximately the same size and shape. 
     Arrow  1040  directs the flow of execution from starting operation  1000  to operation  1042 . Operation  1042  performs combining at least two of the interpolated images employing, for example, a partitioned or other averaging scheme in a second dimension to create the composite image presented to a motion video portal creating the motion video stream. Arrow  1044  directs execution from operation  1042  to operation  1016 . Operation  1016  terminates the operations of this flowchart. 
     Note that in various embodiments of the invention none, some or all of these steps may be found as program steps residing in first memory  210  accessibly coupled  212  to at least one computer  210  contained within motion video portal  70 . 
     Note that means  100 ,  110 ,  120 ,  130 , and  140  of  FIG. 1A  may each include at least one finite state machine and/or at least one computer. Each computer is accessibly coupled to a memory and controlled by a program system made up of program steps implementing the method of operation  1000  and individual program steps  1012 ,  1022 ,  1032 , and  1042 , respectively, as shown in  FIG. 3A . 
     Note that multiple computers may access a shared memory accessibly coupled to each of them. 
       FIG. 3B  depicts a detail flowchart of operation  1022  of  FIG. 3A  for calculating the dense correspondence. 
     Arrow  1060  directs the flow of execution from starting operation  1022  to operation  1062 . Operation  1062  performs calculating a dense correspondence to determine a displacement in at least a first dimension for each of the pixels in the first image digital version which would move each of the pixels to a most nearly corresponding pixel in the image digital versions of at least one other member of the imaging device collection. Arrow  1064  directs execution from operation  1062  to operation  1066 . Operation  1066  terminates the operations of this flowchart. 
       FIG. 4A  depicts a detail flowchart of operation  1032  of  FIG. 3  for generating the interpolated image, for each of the pixels of the interpolated image. 
     Arrow  1070  directs the flow of execution from starting operation  1032  to operation  1072 . Operation  1072  sets the interpolated image pixel to the corresponding pixel of the image digital version where the interpolated image pixel displaced by a partial displacement in at least a first dimension for the image device collection member. Arrow  1074  directs execution from operation  1072  to operation  1076 . Operation  1076  terminates the operations of this flowchart. 
       FIG. 4B  depicts a detail flowchart of operation  1042  of  FIG. 3  for generating each of the pixels of the composite image by combining the interpolated images. 
     Arrow  1090  directs the flow of execution from starting operation  1042  to operation  1092 . Operation  1092  performs combining corresponding pixels of each of the interpolated images employing the averaging scheme partitioned along a second dimension to create the pixel of the composite image. Arrow  1094  directs execution from operation  1092  to operation  1096 . Operation  1096  terminates the operations of this flowchart. 
     Note that the sum of the partial displacements of the image device collection members is approximately equal to the displacement. In certain embodiments of the invention, the partial displacements must belong to a limited collection of incremental values, often a range of integers. The partial displacements may then sum to an incremental value close to the displacement. Suppose the displacement is ‘3’ pixels, with the first and second partial placements may each be ‘1’. Their sum, as ‘2’, is approximately equal to ‘3’. 
     Various embodiments of the invention may alternatively include displacement fractions exactly summing to the displacement. This can be achieved, at least in part, by the use of partial displacements including more than just integers. 
     It is preferred that each of the pixels of any of the images are partially ordered in the one dimension by membership in exactly one member of a partition collection.  FIG. 4C  depicts a detail flowchart of operation  1042  of  FIG. 3  for combining corresponding pixels. 
     Arrow  1110  directs the flow of execution from starting operation  1042  to operation  1112 . Operation  1112  performs combining corresponding pixels of the interpolated images employing the partitioned averaging scheme based upon the pixel membership in a partition collection to create the pixel of the composite image. Arrow  1114  directs execution from operation  1112  to operation  1116 . Operation  1116  terminates the operations of this flowchart. 
     The partition collection may be comprised of a first side collection of the pixels, a center collection of pixels, and a second side collection of pixels. The center collection is between the first side collection and the second side collection in the second dimension 
       FIG. 5A  depicts a detail flowchart of operation  1112  of  FIG. 4C  for combining corresponding pixels. 
     Arrow  1130  directs the flow of execution from starting operation  1112  to operation  1132 . Operation  1132  performs predominantly combining the corresponding pixel of the first interpolated image whenever the composite image pixel is a member of the first side collection. Arrow  1134  directs execution from operation  1132  to operation  1136 . Operation  1136  terminates the operations of this flowchart. 
     Arrow  1140  directs the flow of execution from starting operation  1112  to operation  1142 . Operation  1142  performs predominantly combining the corresponding pixel of the second interpolated image whenever the composite image pixel is a member of the second side collection. Arrow  1144  directs execution from operation  1142  to operation  1136 . Operation  1136  terminates the operations of this flowchart. 
     Arrow  1150  directs the flow of execution from starting operation  1112  to operation  1152 . Operation  1152  performs mixedly combining the corresponding pixels of the at least two interpolated images whenever the composite image pixel is a member of the center collection. Arrow  1154  directs execution from operation  1152  to operation  1136 . Operation  1136  terminates the operations of this flowchart. 
       FIG. 5B  depicts a detail flowchart of operation  1132  of  FIG. 5A  for predominantly combining the corresponding pixel of the first interpolated image whenever the composite image pixel is a member of the first side collection. 
     Arrow  1170  directs the flow of execution from starting operation  1132  to operation  1172 . Operation  1172  determines when the composite image pixel is a member of the first side collection. Arrow  1174  directs execution from operation  1172  to operation  1176  when the determination is ‘Yes’. Arrow  1188  directs execution to  1180  when the determination is ‘No’. 
     Operation  1176  performs predominantly combining the corresponding pixel of the first interpolated image to create the composite image pixel. Arrow  1178  directs execution from operation  1176  to operation  1180 . Operation  1180  terminates the operations of this flowchart. 
       FIG. 6A  depicts a detail flowchart of operation  1142  of  FIG. 5A  for predominantly combining the corresponding pixel of the second interpolated image whenever the composite image pixel is a member of the second side collection. 
     Arrow  1190  directs the flow of execution from starting operation  1142  to operation  1192 . Operation  1192  determines when the composite image pixel is a member of the second side collection. Arrow  1194  directs execution from operation  1192  to operation  1196  when the determination is ‘Yes’. Arrow  1208  directs execution to  1200  when the determination is ‘No’. 
     Operation  1196  performs predominantly combining the corresponding pixel of the second interpolated image to create the composite image pixel. Arrow  1198  directs execution from operation  1196  to operation  1200 . Operation  1200  terminates the operations of this flowchart. 
       FIG. 6B  depicts a detail flowchart of operation  1152  of  FIG. 5A  for mixedly combining the corresponding pixels of the at least two interpolated images whenever the composite image pixel is a member of the center collection. 
     Arrow  1210  directs the flow of execution from starting operation  1152  to operation  1212 . Operation  1212  determines when the composite image pixel is a member of the center collection. Arrow  1214  directs execution from operation  1212  to operation  1216  when the determination is ‘Yes’. Arrow  1228  directs execution to  1220  when the determination is ‘No’. 
     Operation  1216  performs mixedly combining the corresponding pixels of the at least two interpolated images to create the composite image pixel. Arrow  1218  directs execution from operation  1216  to operation  1220 . Operation  1220  terminates the operations of this flowchart. 
       FIG. 7  depicts a detail flowchart of operation  1176  of  FIG. 5B  for predominantly combining the corresponding first interpolated image pixel. 
     Arrow  1250  directs the flow of execution from starting operation  1176  to operation  1252 . Operation  1252  performs setting the composite image pixel to include, for example, at least ½ of the corresponding first interpolated image pixel. Arrow  1254  directs execution from operation  1252  to operation  1256 . Operation  1256  terminates the operations of this flowchart. 
     Arrow  1260  directs the flow of execution from starting operation  1176  to operation  1262 . Operation  1262  performs setting the composite image pixel to include, for example, at least ⅞ of the corresponding first interpolated image pixel. Arrow  1264  directs execution from operation  1262  to operation  1256 . Operation  1256  terminates the operations of this flowchart. 
     Arrow  1270  directs the flow of execution from starting operation  1176  to operation  1272 . Operation  1272  performs setting the composite image pixel to include, for example, at least 15/16 of the corresponding first interpolated image pixel. Arrow  1274  directs execution from operation  1272  to operation  1256 . Operation  1256  terminates the operations of this flowchart. 
     Arrow  1280  directs the flow of execution from starting operation  1176  to operation  1282 . Operation  1282  performs setting the composite image pixel to the corresponding first interpolated image pixel. Arrow  1284  directs execution from operation  1282  to operation  1256 . Operation  1256  terminates the operations of this flowchart. 
       FIG. 8  depicts a detail flowchart of operation  1196  of  FIG. 6A  for predominantly combining the corresponding second interpolated image pixel. 
     Arrow  1330  directs the flow of execution from starting operation  1196  to operation  1332 . Operation  1332  performs setting the composite image pixel to include, for example, at least ¾ of the corresponding second interpolated image pixel. Arrow  1334  directs execution from operation  1332  to operation  1336 . Operation  1336  terminates the operations of this flowchart. 
     Arrow  1340  directs the flow of execution from starting operation  1196  to operation  1342 . Operation  1342  performs setting the composite image pixel to include, for example, at least ⅞ of the corresponding second interpolated image pixel. Arrow  1344  directs execution from operation  1342  to operation  1336 . Operation  1336  terminates the operations of this flowchart. 
     Arrow  1350  directs the flow of execution from starting operation  1196  to operation  1352 . Operation  1352  performs setting the composite image pixel to include, for example, at least 15/16 of the corresponding second interpolated image pixel. Arrow  1354  directs execution from operation  1352  to operation  1336 . Operation  1336  terminates the operations of this flowchart. 
     Arrow  1360  directs the flow of execution from starting operation  1196  to operation  1362 . Operation  1362  performs setting the composite image pixel to essentially the corresponding second interpolated image pixel. Arrow  1364  directs execution from operation  1362  to operation  1336 . Operation  1336  terminates the operations of this flowchart. 
       FIG. 9A  depicts a detail flowchart of operation  1216  of  FIG. 6B  for mixedly combining the corresponding pixel of the at least two interpolated images. 
     Arrow  1400  directs the flow of execution from starting operation  1216  to operation  1402 . Operation  1402  performs calculating a fixed linear combination of the corresponding pixels of the at least two interpolated images to create the composite image pixel. Arrow  1404  directs execution from operation  1402  to operation  1406 . Operation  1406  terminates the operations of this flowchart. 
     Arrow  1410  directs the flow of execution from starting operation  1216  to operation  1412 . Operation  1412  performs calculating a blending linear combination of the corresponding pixels of the at least two interpolated images to create the composite image pixel blending in the second dimension with the composite pixels created by the predominantly combining steps. Arrow  1414  directs execution from operation  1412  to operation  1406 . Operation  1406  terminates the operations of this flowchart. 
       FIG. 9B  depicts a detail flowchart of operation  1412  of  FIG. 9A  for calculating the blending linear combination. 
     Arrow  1450  directs the flow of execution from starting operation  1412  to operation  1452 . Operation  1452  performs calculating a sliding scale linear combination of the corresponding pixels of the at least two interpolated images to create the composite image pixel blending in the second dimension with the composite pixels created by the predominantly combining steps. Arrow  1454  directs execution from operation  1452  to operation  1456 . Operation  1456  terminates the operations of this flowchart. 
     Arrow  1460  directs the flow of execution from starting operation  1412  to operation  1462 . Operation  1462  performs calculating a bulging scale linear combination of the corresponding pixels of the at least two interpolated images to create the composite image pixel blending in the second dimension with the composite pixels created by the predominantly combining steps. Arrow  1464  directs execution from operation  1462  to operation  1456 . Operation  1456  terminates the operations of this flowchart. 
       FIG. 10A  depicts a detail flowchart that shows a central partitioning technique that may be used, interalia, operation  1216  of  FIG. 6B  for for mixedly combining the corresponding pixel of the at least two interpolated images. 
     Arrow  1470  directs the flow of execution from starting operation to operation  1472 . Operation  1472  performs mixedly combining the corresponding pixels varied about an occlusion center corresponding to a geometric centroid estimate of the local participant in the composite image to create the composite image pixelpixel. Arrow  1474  directs execution from operation  1472  to operation  1476 . Operation  1476  terminates the operations of this flowchart. 
     Arrow  1480  directs the flow of execution from starting operation  1216  to operation  1482 . Operation  1482  performs mixedly combining the corresponding pixels varied in a linear manner in the second dimension to create the composite image pixelpixel. Arrow  1484  directs execution from operation  1482  to operation  1476 . Operation  1476  terminates the operations of this flowchart. 
     Arrow  1490  directs the flow of execution from starting operation  1216  to operation  1492 . Operation  1492  performs mixedly combining the corresponding pixels varied in a piece-wise linear manner in the second dimension to create the composite image pixelpixel. Arrow  1494  directs execution from operation  1492  to operation  1476 . Operation  1476  terminates the operations of this flowchart. 
       FIG. 10B  depicts a detail flowchart of operation  1012  of  FIG. 3A  for obtaining the digital version of the image from imaging device collection member as the image member in the synchronized image collection, for each of the imaging device collection members. 
     Arrow  1510  directs the flow of execution from starting operation  1012  to operation  1512 . Operation  1512  performs applying a rectifying transformation associated with the imaging device collection member to the image from the imaging device collection member to create the digital version of the image. 
     Arrow  1514  directs execution from operation  1512  to operation  1516 . Operation  1516  terminates the operations of this flowchart. 
       FIG. 11A  depicts a detail flowchart of an optional step in connection with the method of operation and program system  1000  of  FIGS. 1B and 3A  for generating the composite image, for at least two of the imaging device collection members. 
     Arrow  1530  directs the flow of execution from starting operation  1000  to operation  1532 . Operation  1532  performs determining the rectifying transformation associated with the imaging device collection member, based upon a raw image from the imaging device collection member. Arrow  1534  directs execution from operation  1532  to operation  1536 . Operation  1536  terminates the operations of this flowchart. 
       FIG. 11B  depicts a detail flowchart of operation  1012  of  FIGS. 1B and 3A  for obtaining the digital version of the image, for each of the at least two imaging device collection members. 
     Arrow  1550  directs the flow of execution from starting operation  1012  to operation  1552 . Operation  1552  performs warping the image digital version for the imaging device collection member by the partial displacement for the imaging device collection member to modify the digital version image for the imaging device collection member. Arrow  1554  directs execution from operation  1552  to operation  1556 . Operation  1556  terminates the operations of this flowchart. 
     Further, warping the digital versions of these images has been shown in simulation experiments by the inventor to minimize the computational overhead in the dense correspondence calculation step. This advantageously decreases the computational effort required to create the composite image. 
     Note that certain embodiments of the invention may actively incorporate the operations of  FIGS. 11A and 11B  into a single image operation to achieve approximately the same results of successively performing these operations. 
       FIG. 11C  depicts a detail flowchart of operation  1552  of  FIG. 11B  for warping the image digital version. 
     Arrow  1570  directs the flow of execution from starting operation  1552  to operation  1572 . Operation  1572  performs applying an attenuating factor to the partial displacement for the imaging device collection member to modify the partial displacement for the imaging device collection member. Arrow  1574  directs execution from operation  1572  to operation  1576 . Operation  1576  terminates the operations of this flowchart. 
       FIG. 12A  depicts a detail flowchart, for alternative embodiments of the invention for operation  1572  of  FIG. 11C  for attenuating the partial displacement for the imaging device collection member to modify the partial displacement. 
     Arrow  1590  directs the flow of execution from starting operation  1572  to operation  1592 . Operation  1592  performs multiplying the partial displacement for the imaging device collection member by an attenuating factor and optionally rounding the multiplication to an integral result to modify the partial displacement. Arrow  1594  directs execution from operation  1592  to operation  1596 . Operation  1596  terminates the operations of this flowchart. 
     Arrow  1600  directs the flow of execution from starting operation  1572  to operation  1602 . Operation  1602  performs replacing the partial displacement for the imaging device collection member by a replacement partial displacement whenever the partial displacement is within a displacement interval. Arrow  1604  directs execution from operation  1602  to operation  1596 . Operation  1596  terminates the operations of this flowchart. 
     Such operations as  1602  permit replacement of the partial displacement based upon its inclusion in a range or interval of displacements. If the partial displacement corresponds to a displacement fraction between 1/16 and 3/16, it may be replaced by a partial displacement corresponding to a displacement fraction of ⅛, for example. 
     Arrow  1610  directs the flow of execution from starting operation  1572  to operation  1612 . Operation  1612  performs replacing the partial displacement for the imaging device collection member by a table entry referenced by the partial displacement. Arrow  1614  directs execution from operation  1612  to operation  1596 . Operation  1596  terminates the operations of this flowchart. 
     Note, the attenuating factor may be between 0.0 and 1.1. In certain preferred embodiments of the invention, the attenuating factor is between 0.90 and 1.00. 
       FIG. 12B  depicts a detail flowchart of operation  1592  of  FIG. 12A  for multiplying the partial displacement for the imaging device collection member. 
     Arrow  1730  directs the flow of execution from starting operation  1592  to operation  1732 . Operation  1732  performs rounding upward the result of the partial displacement for the imaging device collection member multiplied by the attenuating factor to modify the partial displacement. Arrow  1734  directs execution from operation  1732  to operation  1736 . Operation  1736  terminates the operations of this flowchart. 
     Arrow  1740  directs the flow of execution from starting operation  1592  to operation  1742 . Operation  1742  performs rounding downward the result of the partial displacement for the imaging device collection member multiplied by the attenuating factor to modify the partial displacement. Arrow  1744  directs execution from operation  1742  to operation  1736 . Operation  1736  terminates the operations of this flowchart. 
     Arrow  1750  directs the flow of execution from starting operation  1592  to operation  1752 . Operation  1752  performs rounding toward zero the result of the partial displacement for the imaging device collection member multiplied by the attenuating factor to modify the partial displacement. Arrow  1754  directs execution from operation  1752  to operation  1736 . Operation  1736  terminates the operations of this flowchart. 
     Arrow  1760  directs the flow of execution from starting operation  1592  to operation  1762 . Operation  1762  performs rounding to nearest the result of the partial displacement for the imaging device collection member multiplied by the attenuating factor to modify the partial displacement. Arrow  1764  directs execution from operation  1762  to operation  1736 . Operation  1736  terminates the operations of this flowchart. 
       FIG. 13A  depicts a detail flowchart of operational method and/or program system  1000  of  FIGS. 1A ,  1 B, and  3 A for generating the composite image which receives specific displacement fractions from the second participant and replaces the displacement fractions in use with the specific displacement fractions 
     Arrow  1790  directs the flow of execution from starting operation  1000  to operation  1792 . Operation  1792  performs receiving via the video delivery system from the second participant a specific displacement fraction for the imaging device collection member, for the at least two of the imaging device collection members. Arrow  1794  directs execution from operation  1792  to operation  1796 . Operation  1796  terminates the operations of this flowchart. 
     Arrow  1800  directs the flow of execution from starting operation  1000  to operation  1802 . Operation  1802  performs replacing the displacement fraction with the specific displacement fraction for the imaging device collection member, for the at least two imaging device collection members. Arrow  1804  directs execution from operation  1802  to operation  1796 . Operation  1796  terminates the operations of this flowchart. 
       FIG. 13B  depicts various potential imaging device collection member placements in relationship with display  30 . 
     Note that at least two imaging device collection members may each include equipment containing a Charge Coupled Device (CCD) array. The equipment may include more than one CCD array per imaging device collection member. 
     At least one of the imaging device collection members may further preferably embody at least one video camera. At least two imaging device collection members,  41  and  42 , are preferably horizontally positioned with respect to the head of local participant  10 , as seen through inspection of  FIGS. 1A ,  2 , and  13 B. 
     At least two imaging device collection members,  43  and  44 , may be vertically positioned with respect to the head of local participant  10 , as seen through inspection of  FIGS. 2 and 13B . 
     At least two imaging device collection members,  45  and  46 , or alternatively  47  and  48 , may be diagonally positioned with respect to the head of local participant  10 , as seen through inspection of  FIGS. 2 and 13B . 
     At least two imaging device collection members may preferably be symmetrically positioned about a local display as seen by local participant  10 , as seen through inspection of  FIGS. 2 and 13B . By way of example, any of the pairs  41  and  42 ,  43  and  44 ,  45  and  46 , or alternatively  47  and  48  display such symmetry. Additionally, groupings of more than two imaging device collection members may exhibit symmetry. By way of example, the quadruple  41 ,  42 ,  43  and  44 , as well as the quadruple  45 ,  46 ,  47  and  48  display such symmetry. 
     Note that as used herein, an imaging device collection may preferably include, but is not limited to, two, three and/or four members. 
     As used herein the first dimension and the second dimension belong to a collection comprising an essentially vertical dimension  60 , an essentially horizontal dimension  62 , an essentially diagonal dimension  64  and  66  as well as an essentially angular dimension  68 . As used herein, these dimensions  60 – 66  are preferably aligned with two imaging device collection members. The essentially angular dimension  68  may preferably use the approximate center of the pixel array as the angular center. Alternatively, the essentially angular dimension may use the occlusion center corresponding to a geometric centroid estimate of the local participant in the composite image. 
     In certain embodiments of the invention, whenever there are exactly two imaging device collection members being used, the first dimension and second dimension may be the same. 
     Whenever there are an odd number of imaging device collection members in use, the second dimension may preferably be the essentially angular dimension. 
     By way of example, consider an embodiment of the invention using three imaging devices,  43 ,  45  and  47 . The first dimension, for a given correspondence, is typically aligned along a line connecting the two imaging devices for which the correspondence is calculated. Only one such first dimension would be horizontal in a three camera arrangement as shown. One possibility, though, is that the first dimension is horizontal as defined by the epipolar lines of the rectiied images. Note that rather than just one center collection, as many as three center collections as well as three side collections of pixels may be preferred. Note further that while the composite image is comprised of essentially the array of pixels as discussed previously, there is also the potential of mapping individual pixels by an ordering implicit with the second dimension. 
       FIG. 14A  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3 A for generating the composite image. 
     Arrow  1830  directs the flow of execution from starting operation  1000  to operation  1832 . Operation  1832  performs the video delivery system presenting the local participant the motion video stream conveying eye contact based upon the composite image succession. Arrow  1834  directs execution from operation  1832  to operation  1836 . Operation  1836  terminates the operations of this flowchart. 
       FIG. 14B  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3  for generating the composite image, for at least two of the imaging device collection members. 
     Arrow  1850  directs the flow of execution from starting operation  1000  to operation  1852 . Operation  1852  performs providing to the motion video portal a succession of the images from the imaging device collection member for the video delivery system to present to the local participant. Arrow  1854  directs execution from operation  1852  to operation  1856 . Operation  1856  terminates the operations of this flowchart. 
       FIG. 14C  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B and  3  for generating the composite image. 
     Arrow  1870  directs the flow of execution from starting operation  1000  to operation  1872 . Operation  1872  performs specifying a point P from which the at least two imaging device collection members are displaced. Arrow  1874  directs execution from operation  1872  to operation  1876 . Operation  1876  terminates the operations of this flowchart. 
       FIG. 15A  depicts a detail flowchart of operation  1872  of  FIG. 14C  for specifying the point P. 
     Arrow  1890  directs the flow of execution from starting operation  1872  to operation  1892 . Operation  1892  performs operating a tactile interface controlled by the participant for specifying the point P. Arrow  1894  directs execution from operation  1892  to operation  1896 . Operation  1896  terminates the operations of this flowchart. 
     Arrow  1900  directs the flow of execution from starting operation  1872  to operation  1902 . Operation  1902  performs specifying the point P based upon interactions with the participant. Arrow  1904  directs execution from operation  1902  to operation  1896 . Operation  1896  terminates the operations of this flowchart. 
     Arrow  1910  directs the flow of execution from starting operation  1000  to operation  1912 . Operation  1912  performs specifying the point P based upon interactions with the second participant reported by the video delivery system. Arrow  1914  directs execution from operation  1912  to operation  1916 . Operation  1916  terminates the operations of this flowchart. 
     Arrow  1920  directs the flow of execution from starting operation  1000  to operation  1922 . Operation  1922  performs specifying the location of the participant&#39;s eyes within the composite image based upon information from the second participant reported by the video delivery system. Arrow  1924  directs execution from operation  1922  to operation  1916 . Operation  1916  terminates the operations of this flowchart. 
     Note that as used herein, a tactile interface refers to at least one of a knob, a slider, a touchpad, a mouse, a trackball, and/or a keyboard. 
       FIG. 15B  depicts a detail flowchart of operational method and program system  1000  of  FIGS. 1A ,  1 B, and  3 A for generating the composite image. 
     Arrow  1930  directs the flow of execution from starting operation  1000  to operation  1932 . Operation  1932  performs providing a video conference between at least the local participant and at least the second participant based upon the motion video stream. Arrow  1934  directs execution from operation  1932  to operation  1936 . Operation  1936  terminates the operations of this flowchart. 
     Note that the video conference may be only presented to participants, or may be presented to an audience including more than just the participants. Note further that the motion video stream may include more than motion video stream versions for different participants, as well as non-participating audiences. These different versions may provide compatibility with more than one video stream format. By way of example, the non-participating audience may receive an analog video format such as NTSC or PAL, while the participants receive a digital motion format such as MPEG1 or H.261. 
     Arrow  1940  directs the flow of execution from starting operation  1000  to operation  1942 . Operation  1942  performs providing a video phone session between the local participant and the second participant based upon the motion video stream. Arrow  1944  directs execution from operation  1942  to operation  1936 . Operation  1936  terminates the operations of this flowchart. 
     Arrow  1950  directs the flow of execution from starting operation  1000  to operation  1952 . Operation  1952  performs providing a video kiosk supporting video communication between at least the local participant and at least the second participant based upon the motion video stream. Arrow  1954  directs execution from operation  1952  to operation  1936 . Operation  1936  terminates the operations of this flowchart. 
     Arrow  1960  directs the flow of execution from starting operation  1000  to operation  1962 . Operation  1962  performs providing a video training session between at least the local participant and at least the second participant based upon the motion video stream. Arrow  1964  directs execution from operation  1962  to operation  1936 . Operation  1936  terminates the operations of this flowchart. 
     Note that in certain preferred embodiments, at least one of these operations are supported. 
     Accordingly, although the invention has been described in detail with reference to particular preferred embodiments, persons possessing ordinary skill in the art to which this invention pertains will appreciate that various modifications and enhancements may be made without departing from the spirit and scope of the claims that follow.