WO2013151561A1

WO2013151561A1 - Video frame sequence control system and method

Info

Publication number: WO2013151561A1
Application number: PCT/US2012/032605
Authority: WO
Inventors: Kar-Han Tan; Ian N Robinson; Alan A MCREYNOLDS
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2012-04-06
Filing date: 2012-04-06
Publication date: 2013-10-10

Abstract

A video sequence control system 100 is described that includes a switching component 102 coupled to a video source and a switch control signal 108. The video source 110 produces analog video signals representative of a sequence of input image video frames. The switching component 102 switches between analog video signals representative of at least input image video frames and crosstalk reduction frames. Switching from an input image video frame type to a crosstalk reduction frame type requires switching the voltage values of the analog video signals representative of the input image video frame to a voltage signal representative of the crosstalk reduction frame type. A video frame sequence control component 104 provides video frame output sequence information including timing information and sequence information of the video frame to be output by the switching component 102.

Description

VIDEO FRAME SEQUENCE CONTROL SYSTEM AND METHOD

BACKGROUND

[0001] When displaying a projected image and simultaneously capturing images of the projected scene and the display, there can be crosstalk between the projected images and the captured content. The crosstalk can reduce the image quality (i.e. brightness, color) of the captured image frames and additional cause distracting flicker on the display. Various attempts have been made to reduce crosstalk in the dual projection/image capture systems. For example, the display may be changed from a passive screen display screen to an active switchable diffuser to reduce crosstalk. However, although crosstalk may be reduced when using the active switchable diffuser for the display, an active diffuser display screen can limit the useful duty cycle of both the projector and the image capture device used in the system.

BRIEF DESCRIPTION OF DRAWINGS

[0002] The figures depict implementations/embodiments of the invention and not the invention itself. Some embodiments are described, by way of example, with respect to the following Figures.

[0003] Figure 1 A shows a schematic drawing of a video sequence control system according to an example of the invention; [0004] Figure 1 B shows a more detailed drawing of the switching component of the video sequence control system shown in Figure 1 A according to an example of the invention;

[0005] Figure 1C shows a more detailed drawing of the switching component of the video sequence control system shown in Figure 1A according to an alternative example of the invention;

[0006] Figure 1 D shows a more detailed drawing of the switching component of the video sequence control system shown in Figure 1 A according to an alternative example of the invention;

[0007] Figure 2 shows the video sequence control system shown in Figure 1 A where the video frame sequence frames output by the video sequence control system is displayed on a see-through display screen according to an example of the invention;

[0008] Figure 3 shows a flow diagram for a method for controlling the output of a video sequence according to an example of the invention;

[0009] Figure 4 shows a computer system for implementing the method shown in Figure 3 described in accordance with examples of the present invention. [0010] The drawings referred to in this Brief Description should not be understood as being drawn to scale unless specifically noted.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] For simplicity and illustrative purposes, the principles of the embodiments are described by referring mainly to examples thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent, however, to one of ordinary skill in the art, that the embodiments may be practiced without limitation to these specific details. Also, different embodiments may be used together. In some instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the description of the embodiments.

[0012] Referring to Figure 1A shows a video sequence control system 100 comprising: a switching component 102 coupled to a video source (not shown) and a switch control signal 108, the video source 110 providing analog video signals representative of a sequence of input image video frames, the switching component 102 for switching between analog video signals representative of at least input image video frames and crosstalk reduction frames, wherein the switch from an input image video frame type to a crosstalk reduction frame type requires switching the voltage values of the analog video signals representative of the input image video frame to a voltage signal representative of the crosstalk reduction frame type; and a video frame sequence control component 104 communicatively coupled to the switching component 102 for providing video frame output sequence information including timing information and sequence information of the video frame to be output to the switching component 102, wherein the timing information of the output of the video frame sequence corresponds to the timing of a switching signal 108. [0013] The video sequence control system 100 takes a video stream input from a video source 110 and outputs a (1 ) modified output video stream and (2) a synchronization output signal. In one example, the modified output video sequence is created by modifying some of the original input images to images having a different frame type. Assume for example a series of input image frames from a video source. In one case, the video sequence control system 100 simply outputs the original image. In this case, the original input image video is allowed to pass through the switching component 102 unchanged. However, according to the output sequence defined by the video frame sequence control component 104, some of the original input image video frames received may be modified. For example, for one case where crosstalk reduction frames are defined in the output video sequence, instead of maintaining their original voltage values representative of the input image - the signal values of the input image videos are switched from their original levels to voltage value levels representative of the crosstalk reduction frames for the implemented system. In one example, the crosstalk reduction voltage value levels that are output may be optimized dependent upon the type of display screen the video sequence output is displayed upon and the method or type of display system.

[0014] In one example, whether an input video frame or other frame is modified to create the video output stream and how frames slotted for modification are changed is dependent upon frame type. The at least two frame types available for output include: (1) image input video frames and (2) crosstalk reduction frames. Input image video frames refer to the input video frames that are not modified but instead are directly output in the output video frame sequence. [0015] Figure 2 shows the video sequence control system 100 shown in Figure 1A where the output video stream 236 is displayed on a see-through display screen 250 according to an example of the invention. In the

implementation described with respect to Figure 2, the output video frame sequence 238 is generated by switching between two types of frames - input image video frames 244a, 244b and crosstalk reduction frames 242a, 242b. The crosstalk reduction frames 242a, 242b in the output video sequence have the function of reducing crosstalk in the system in order to improve image quality of the displayed image.

[0016] Referring to Figures 1 A and Figure 2 show a video source 110 coupled to a video sequence control system 100. Referring to Figure 2, the video source 110 produces an input video stream 112 of input video frames 106. Various sources may be used to generate the input video stream 112. In one example, video could originate from video streamed from a network 262. In another example, the video source 110 could be a graphics adapter in a computing device. In another example, the video source 110 could be a video camera that inputs the captured images to the graphics adapter in a computing device.

[0017] Figure 2 shows the video sequence control system 100 shown in Figure 1 A where the output video frames 236 are displayed on a see-through display screen 250. In the example shown in Figure 2 the video sequence control system 100 outputs a video frame sequence 238 to a projector 248 that drives the display 250. The video sequence control system 100 outputs a synchronization output signal 224 to the image capture device 246 to signal to the image capture device 246 when image capture of the scene should occur. [0018] In one example, the video sequence control system 100 modifies an input stream 112 to an output pattern that alternates between input image frames represented by frames 244a, 244b and black crosstalk reduction frames 242a, 242b. In one example, the crosstalk reduction frame 242a, 242b is a dimmed or reduced intensity frame. Dimmed or reduced intensity video frames have pixel intensity values lower than the corresponding image frames in the same video sequence. The dimmed image can be a reduced intensity version of the black frame (i.e. a gray frame) or alternatively, a dimmed version of the image frame. In the example shown in Figure 2, the crosstalk reduction frames 242a, 242b are black frames. The purpose of the lower intensity video frame is to provide a time interval when the image capture device 120 is capturing a video frame image of the scene behind the see-through display screen which minimizes the interference or crosstalk caused by the projected image. If the black image frame is represented by a low voltage signal or ground, then the dimmed version of the image may be represented by ground or a low value intermediate voltage node.

[0019] In the example shown in Figure 2, the video frame output sequence 236 is projected onto a display screen 250 by a projector 248. In one example, the display is a see-through display screen 250 comprised of a relatively low concentration of diffusing particles embedded within a transparent screen medium. The low concentration of diffusing particles allows a camera 246 or other image capture device to capture an image through the screen 250 (providing that the subject is well lit), while diffusing enough of the light from the projector 248 to form an image on the display screen. In another example, the display screen 250 can be a holographic film that has been configured to accept light from the projector 248 within a first range of angles and to transmit light that is visible to the remote participant within a different range of viewing angles. The holographic film is otherwise transparent. In both examples, light projected onto the first surface 256 within the first range of angles can be observed by viewing the second surface 258, but light striking the second surface 258 is transmitted through the screen to the camera. In both examples the camera also captures light from the projector diffused or scattered off of the first surface.

[0020] In the example shown in Figure 2, the crosstalk reduction frames (e.g. 242a, 242b) in the output sequence are black frames (no light output) which simulates the projector 108 being in an off state. In one example, the image capture device 246 is a video camera. The video camera is synchronized to capture an image during the time period when the crosstalk reduction frame is being displayed. For the case where there is a see-through display screen, the video camera 246 captures the scene in front of the display screen, the display and the scene behind the see-through display screen. Thus, for a video conferencing example where there is a participant 252 on the other side of the display screen - the video camera 246 captures the image of the participant on the other side of the display screen. Because the projector is off when the image is captured, the camera does not capture the projected image.

[0021] Although in the example shown in Figure 2, the crosstalk reduction frames 242a, 242b shown in the output sequence 236 are black frames - in an alternative example the crosstalk reduction frames could be another color, for example white frames. In one example, the crosstalk reduction frames are optimized based on the display. For example, for the configuration shown in Figure 2 where there is a see-through display screen and the projector works by adding light to the display surface, a black frame minimizes the light added thereby reducing the crosstalk. In another alternative example, the display screen could be an LCD panel display. An LCD panel works by blocking light and is most transparent when it is displaying the highest intensity. Thus, in one example where an LCD display is used, the crosstalk reduction frames 242a, 242b in the output sequence 236 would be a white frames- as for an LCD display white frames would reduce crosstalk.

[0022] In one alternative example, the crosstalk reduction frame 242a, 242b is a brightened version of the input sequence. Brightened or increased intensity video frames have pixel intensity values higher than the corresponding image frames in the same video sequence. In one example shown in Figure 2, the crosstalk reduction frames 242a, 242b are white frames. In one alternative example, the brightened image is a brightened version of the image frame. The purpose of the increased intensity video frame is to provide a time interval when the image capture device 120 is capturing a video frame image on the LCD display screen which minimizes the interference or crosstalk caused by the projected image. If the white image frame is represented by a high voltage signal such as Vcc, then the brightened version of the image may be represented by V_∞ or a high value intermediate voltage node.

[0023] In the example shown in Figure 2, the repetitive pattern 238 is a pattern of alternating crosstalk reduction frames and image frames. However, the output video sequence could be different dependent upon the desired output and results. For example, the output video sequence could be n crosstalk reduction frame followed by m image frames. For purposes of example, say one crosstalk reduction frame followed by three image frames. For example, a video sequence where number of image frames is increased compared to the first example (single crosstalk reduction frame followed by a single image frame) as the increased number of image frames in the sequence can improve the quality of the displayed image.

[0024] Figure 1A shows a schematic drawing of a video sequence control system 100 according to an example of the invention. In one example, the switching component 102 switches between signals representative of different frame types based on the schedule or output sequence determined by the video frame sequence control component 104 wherein the frame types include at least image video frames and a crosstalk reduction frames. In one example, the timing of switching between frame types is controlled by the switching control signal 108. Switching from an input image video frame to an alternative frame type requires switching the voltage values of the analog video signals representative of the input image video frames to a voltage signal representative of the different (crosstalk reduction) frame type.

[0025] In one example, where the crosstalk reduction frame is a black frame the signal voltage level during the frame period will be switched to a voltage level representing black. This level could be zero, ground or another specific voltage required by the display hardware or alternatively to reduce crosstalk reduction could be used. For example, instead of a voltage level tied to zero or ground, a dimmed voltage level of 0.3 volts might be optimal and might used to represent the "black" frame. Similarly, where the crosstalk reduction frame is a white frame, the signal voltage level during the frame period will be switched to a level representing white. The level could be ν_∞, the power supply voltage level or another specific voltage required by the display hardware. Switching to the crosstalk reduction frame signal voltage level could be implemented by switching to a regulated voltage line. For example ν_∞, or some other calculated voltage value could optimally be used to reduce crosstalk. For example, instead of a voltage level tied to 5 volts or ν_∞, a brightened voltage level of 4.7 volts might be optimal and might used to represent the "white" frame.

[0026] The switching component 104 and the video sequence control component 102 are both communicatively to a video source 110. Referring to Figure 1A, the video source 110 outputs a plurality of signals to the video sequence controller 100 including but possibly not limited to: analog RGB signals 118, 120, 122, ground 136, an a synchronization signal VSYNC 138. The analog RGB signals 118, 120, 122 and the ground signal 136 from the video source are input into the switching component 102. In addition, the switch control signal 108 from the video frame sequence control component is also an input to the switching component 102.

[0027] As previously stated, the switching component 102 and the video sequence control component 104 are both communicatively to a video source 110. The VSYNCH signal 138 from the video source is input to the video sequence control component 102. In addition, inputs to the video frame sequence control component 104 include a JTAG Connector signal 140 from a JTAG connector 142 and optical isolations signal 144 from an optical isolation component 146. The optical isolation input signal component 146 and optical isolation output

components 148a, 148b both provide optical isolation to prevent external surges from damaging the video sequence controller 100. In one implementation, the video frame sequence control component 102 is a microcontroller and the JTAG connector 142 is used to program instructions into the video frame sequence control component via the JTAG connection signal 140. [0028] In one example, the video frame sequence control component 104 provides video frame output sequence information including timing information and sequence information of the video frame to be output by the switching component 102. In one example, the programmed instructions provide control information (via the control signal 108) to the switching component in order to determine the video frame output sequence of the switching component 102. In one example, the programmed instructions include information regarding the frame type to be output (and the voltage levels associated with each frame type), the sequence of frame types and the timing of each frame type to be output.

[0029] The video sequence control system 100 produces a synchronization output signal 138. Referring to example shown in Figure 2, the synchronization output signal 138 is communicatively coupled to an image capture device 246 and is used to provide a signal to the image capture device 246 related to the occurrence of the at least one crosstalk reduction frame (e.g. 242a, 242b). The synchronization output signal 224 is used to trigger the capture of an image by the image capture device 246 when a crosstalk reduction frame 242a, 242b is being projected.

[0030] In one example, the synchronization output signal 138 is directly coupled to the image capture device 246. In the example shown in Figure 2, the image capture device 246 is communicatively coupled to the synchronization output signal via an optional signal converter 254. In one example, the signal converter could reduce the frequency of the synchronization trigger frequency. In another example, a image capture device 246 might require a specific signal pattern that follows an industry standard protocol. For this case, the signal converter 254 could translate a simple triggering synchronization output signal 224 to the pattern according to industry standard protocol.

[0031] In one example, the synchronization output signal 138 provides both a synchronization signal and a command signal to the image capture device 246. In one example, the synchronization output signal 138 provides information to the image capture device of when the crosstalk reduction frame is being projected. The command signal line can provide information to the image capture device of what camera function is to perform. In one example, the command signal to the image capture device provides a command to the image capture device to begin or terminate image capture. In the example shown in Figure 2, the timing of the image capture by the camera is done in synchronization with the projection of the crosstalk reduction frame.

[0032] A synchronization output signal 138 is sent to the image capture device 246 to instruct it to capture an image of the scene when the crosstalk rejection frames are being projected onto the display screen. For example, assuming the black crosstalk reduction frame 242a is projected at a time t_pr0ji . Then the camera starts image capture at this time and outputs a corresponding photograph 260a. The corresponding photograph is of the display, the scene in front of the display and for the case of a see-through screen, the viewer behind the display screen. Similarly assuming a second black crosstalk rejection frame 242b is projected at time t_pr0j2, then the camera captures an image and outputs the corresponding photograph 260b. [0033] Referring to Figure 1 B shows a more detailed drawing of the switching component of the video sequence control system shown in Figure 1A according to an example of the invention. In the implementation shown in Figure 1B, the switching component 102 switches between analog RGB signals representative of the input image video frames and ground (the signal

representative of the crosstalk reduction frame.) As switching to ground is equivalent to producing a black video frame, the switching component 102 causes the output of the switching component to switch between the input image video frame and a black video frame. Alternating the voltage level between a voltage level representative of an input image video frame and ground would in effect mirror the output video frame sequence shown in Figure 2 - an output sequence pattern of alternating image video frames and black crosstalk reduction frames.

[0034] Referring to Figure 1 B, signals representative of video frames from a video source are input into the switching component 102. In the implementation shown, the signals representative of the input image video frame are analog RGB signals 118a, 118b, 120a, 120b, 122a, 122b. Together the RGB signal lines provide a color image for possible display. In the example shown, each RGB signal line 118, 120, 122 is connected to a corresponding switch 124, 126, 128. The position of the switch (Hi/Low) is controlled by a switch control signal 108. The switch control signal 108 is output from the video frame sequence control component 104. The switch control signal 108 sends a signal to switches 124, 126, 128 which controls the position of (here high or low position) and timing of the position of the switches 124, 126, 128. In the implementation shown in Figures 1B and 1C, the switches 124, 126, 128 are ganged so that when the switch control signal 108 indicates the switch position is high, then all of the switches 124, 126, 128 close to connect nodes 130a, 132a, 134a to ground 136 (a lower voltage compared to the voltage signal of the input image). When the switch control signal 108 indicates the switch position is low, then the switches 124, 126, 128 close to connect to nodes 138c, 140c, 142c to the voltage signal representative of the original input image video frame signal value.

[0035] In one example, at least a portion of the output video frames are modified so that they are dimmed. In an alternative example, at least a portion of the output video frames are modified so that they are brightened. By dimmed we mean that the intensity of the video frame (or other value representative of the image) is lower than the corresponding input image video frame being modified and output by the switching component. For example with reference to Figure 1C, the dimmed image could be described as a reduced or lower value

(intensity/voltage) image output according to the voltage divided signal (a lower voltage compared to the input image signals.) In one example, the dimmed image could be a black frame (tied to ground.) In another example, the dimmed image could be a grayed video frame (reduced intensity version of the black frame) or another lower intensity version of the input image video frame.

[0036] Figure 1C shows a more detailed drawing of the switching component of the video sequence control system shown in Figure 1 A according to an alternative example of the invention. Similar to the implementation shown in Figure 1B and the implementation shown in Figure 1C video frames from a video source are input into the switching component. In the implementation shown, the signals representative of the input image video frame are analog RGB signals 118a, 118b, 120a, 120b, 122a, 122b. Together the RGB signal lines provide a color image for possible display. In the example shown, each RGB signal line 118, 120, 122 is connected to a corresponding switch 124, 126, 128 inside the switching

component.

[0037] Compared to the implementation shown in Figure 1 B, the

implementation shown in Figure 1C includes a voltage divider and voltage divider node added for each input signal. The position of the switch (Hi/Voltage Divided Signal/Low) is controlled by a switch control signal 108. The switch control signal 108 is output from the video frame sequence control component 102. The switch control signal 108 sends a signal to switches 124, 126, 128 which controls the position of the switch with respect to nodes (here high, intermediate (voltage- divided) or low position) and the timing of the position changes of the switches 124, 126, 128.

[0038] In the implementation shown in Figures 1B and 1C, the switches are ganged so that when the switch control signal indicates the switch position is high, then all of the switches 124, 126, 128 close to connect nodes 130a, 132a, 134a to ground 136 (a lower voltage compared to the voltage signal of the input image). When the switch control signal indicates the switch position is low, then the switches 124, 126, 128 close to connect to nodes 130c, 132c, 134c to the voltage signal representative of the original input image video frame signal value.

[0039] In the implementation shown in Figure 1C, the switching component is capable of switching between analog RGB signals representative of the input image video frames, a voltage-divided signal, and ground. Switching to the ground node 136 is equivalent to producing a black video frame for output. Switching to the image video frame nodes 134a-c (signals representative of the image video) is equivalent to outputting the original input image video without modification.

Switching to the node representative of a voltage-divided node 130b, 132b, 134b is equivalent to the voltage divided signal representative (a reduced voltage signal) of the original input signal. Referring to Figure 1C, shows a voltage divider circuit located between the signals representative of ground and the input image video frame, for each of the switching nodes 130b, 132b, 134b of the voltage divided signal. In the example shown in Figure 1C, each voltage divider includes impedances (140a and 140b, 142a and 142b, 144a and 144b), where the voltage divider node is positioned between the impedances.

[0040] In the example shown in Figure 2, the crosstalk reduction frame is a black frame. However, instead of a outputting a black crosstalk reduction as shown in Figure 2, the switching component can alternatively output signals representative of other dimmed images. In one example, instead of outputting a black image- a gray image having some percentage of the possible intensity range of the original input image could be output. For example, a gray crosstalk reduction frame having an intensity of 50% of the original input image could be output. In another example, the dimming can be applied at continuous varying levels that are software controllable. For example, the switching component could include voltage dividers that result in a modified output video frame that are at varying percentages (say for purposes of example 75%, 50% and 25% of the intensity) of the input image. The percentage intensity is related to the impedance of the voltage dividers. For example, in the example shown in Figure 1C, the voltage at the voltage divided node is dependent upon the two impedance values in the voltage divider. For example, if the values of the two impedances are equal, then the output intensity at the voltage divided node would be 50% of the intensity of the input image. [0041] In one example, the crosstalk reduction frame intensity might be reduced from its highest possible intensity to a lower intensity level. One case where this might be a reasonable option would be the case where the projected image frames are likely to be very bright. For the case where the projected images go between a very bright projected image to a black video frame (the crosstalk reduction frame), the high amount of change between the two projected images that the human eye perceives - increases the perception of flashing and flicker. To reduce this effect, in one example, the crosstalk reduction frame color could be changed from black to a gray color. In another example, where the display screen is not bright (in some cases where a see-through display is used), it is not necessary to have the crosstalk reduction frame be completely black in order to substantially reduce crosstalk.

[0042] Figure 1D shows a more detailed drawing of the switching component of the video sequence control system shown in Figure 1A according to an alternative example of the invention. In the implementation shown in Figure 1C, the switching component is capable of switching between analog RGB signals representative of the input image video frames, a high voltage signal ν_∞, and ground. In one example, Vcc is the highest voltage available to the system and is the power supply voltage. Switching to the ground node 136 is equivalent to producing a black video frame for output. Switching to the image video frame nodes 134a-c (signals representative of the image video) is equivalent to outputting the original input image video without modification. Switching to the node representative of a high voltage signal 130b, 132b, 134b is equivalent to producing a white crosstalk reduction frame. In one example, although the switching component 102 would be capable of outputting either a black frame or a white frame - only one of the two nodes (node representative of the black crosstalk reduction frame or node representative of the white crosstalk reduction frame) would be be used. For example, for the case where the display screen is an LCD panel - only the nodes representative of the high voltage signals and the input voltage signals might be used. Further, although the examples shown in the switching component show two or three switching nodes -additional switching nodes could be added dependent upon the desired output video frame sequence and desired flexibility (how many voltage level representations are desirable) for the switching component.

[0043] Referring to Figure 1 A, the video frame sequence control component 104 is coupled to the switching component 102 and provides the switching component video frame output sequence information. The video frame output sequence information includes sequence switching information and timing information. The video frame output sequence information provides information that the switching component 102 uses to determine how and when to switch between switching nodes (and their corresponding voltages)- thereby modifying the output signals representative of the video frame. In one example, the video frame output sequence information is transmitted from the video frame sequence control component 104 to the switching component 102 via the switching control signal 108. Responsive to the video frame output sequence information transmitted to the switching component, the switching component determines whether it needs to stay at its current node position or switch from its current switching node to an alternative switching node and if a switch to an alternative switching node occurs, the timing of the switch. [0044] As previously stated, the video frame output sequence information includes video sequence switching information and timing information. The timing information corresponds to the timing of the position of the switches within the switching component - switching position maintained at its current node or switching position within the switching component is changed from one switching node to another alternative switching node. The timing information is transmitted (along with the video sequence switching information) on the switching control signal line 108. The timing information is derived from and is related to the VSYNCH signal 138. In the example shown, the VSYNCH signal provides information related to the timing of the beginning and/or end of the video frame. In the example described, switching within the switching component 102 corresponds to the beginning of the video frame.

[0045] In addition to timing information, the video frame output sequence information includes video sequence switching information. The sequence switching information tells the switching component when to switch from a first node to a second alternative node. For example, for the example shown with respect to Figure 2, the video frame output sequence 238 requires switching between the input image video frame and a black crosstalk reduction frame. In other words, switching between the voltage signals of the original input image received from the video source and the ground signal.

[0046] The video sequence switching information can be characterized in multiple ways. For example, switching within the context of the switching component 102 can be thought of as switching between node positions, switching between voltage levels, switching between frames types, etc. For the example shown in Figure 2 the switch between the image frame and the black crosstalk frame, switching information controls and can be thought of as switching between position from low to high for nodes 130, 132 and 134, switching between frame types (switching between an image frame and a crosstalk reduction frame) or switching between voltage levels (switching between a high voltage level (the original input RGB signal) and a lower voltage level (ground voltage for the crosstalk reduction frame)). Because of the correspondences between the switching nodes, the voltages and the frame types, these correspondences can be thought of as equivalently describing the same switching function.

[0047] Figure 3 shows a flow diagram for a method for controlling the output of a video sequence according to an example of the invention. The method includes the steps of: receiving analog signals representative of a sequence of input video frames (step 310); determining the frame types of the video to be output according to an output video frame sequence, the frame types including at least input image video frames and crosstalk reduction frames (step 320);

responsive to the frame type of the output video frame sequence, positioning the switching component to connect to a node representative of the frame type (step 330); outputting the analog signal of the video frame associated with the node representative of the frame type.

[0048] Referring to Figure 3, analog signals representative of a sequence of input video frames is received. In one example, the input video frames are received from a video source 110. Based on information provided by a video frame sequence control component 104, the video sequence control component determines the frame types of the video to be output according to an output video frame sequence. The frame types should include at least input image video frames and crosstalk reduction frames. [0049] Responsive to the frame type of the video frame in the output sequence, the switching component 102 of the video frame sequence controller 100 switches to a node that is representative of the frame type to be output according to the video frame output sequence. Thus, the input video frame signal being processed may remain the same or alternatively may be modified according to the desired output video frame sequence. If the input node is modified, it is modified by switching from its previous node position to a node that corresponds to the frame type video output frame sequence. For example, when switching from outputting the original input image to a crosstalk reduction frame - the switching component switches the node to a node representative of the crosstalk reduction frame. In one example, the crosstalk reduction frame node has RGB signals connected to ground (black frames). In another example, the crosstalk reduction frame node has RGB signals that are voltage reduced signals. In another example, the crosstalk reduction frame node has RGB signals connected to a high voltage signal V_cc (white frames).

[0050] Figure 4 shows a computer system for implementing the method shown in Figure 3 described in accordance with examples of the present invention. The computing apparatus 400 includes one or more processor(s) 402 that may implement or execute some or all of the steps described in the method 300.

Commands and data from the processor 402 are communicated over a

communication bus 404. The computing apparatus 400 also includes a main memory 406, such as a random access memory (RAM), where the program code for the processor 402, may be executed during runtime, and a secondary memory 408. The secondary memory 408 includes, for example, one or more hard drives 410 and/or a removable storage drive 412, representing a removable flash memory card, etc., where a copy of the program code for the method 400 may be stored. The removable storage drive 412 reads from and/or writes to a removable storage unit 414 in a well-known manner.

[0051] These methods, functions and other steps described may be embodied as machine readable instructions stored on one or more computer readable mediums, which may be non-transitory. Exemplary non-transitory computer readable storage devices that may be used to implement the present invention include but are not limited to conventional computer system RAM, ROM, EPROM, EEPROM and magnetic or optical disks or tapes. Concrete examples of the foregoing include distribution of the programs on a CD ROM or via Internet download. In a sense, the Internet itself is a computer readable medium. The same is true of computer networks in general. It is therefore to be understood that any interfacing device and/or system capable of executing the functions of the above-described examples are encompassed by the present invention.

[0052] Although shown stored on main memory 406, any of the memory components described 406, 408, 414 may also store an operating system 430, such as Mac OS, MS Windows, Unix, or Linux; network applications 432; and a video sequence control component 434. The operating system 430 may be multi- participant, multiprocessing, multitasking, multithreading, real-time and the like. The operating system 430 may also perform basic tasks such as recognizing input from input devices, such as a keyboard or a keypad; sending output to the display 420; controlling peripheral devices, such as disk drives, printers, image capture device; and managing traffic on the one or more buses 404. The network applications 432 includes various components for establishing and maintaining network connections, such as software for implementing communication protocols including TCP/IP, HTTP, Ethernet, USB, and FireWire.

[0053] The computing apparatus 400 may also include an input devices 416, such as a keyboard, a keypad, functional keys, etc., a pointing device, such as a tracking ball, cursors, mouse 418, etc., and a display(s) 420. A display adaptor 422 may interface with the communication bus 404 and the display 420 and may receive display data from the processor 402 and convert the display data into display commands for the display 420.

[0054] The processors) 402 may communicate over a network, for instance, a cellular network, the Internet, LAN, etc., through one or more network interfaces 424 such as a Local Area Network LAN, a wireless 402.11x LAN, a 3G mobile WAN or a WiMax WAN. In addition, an interface 426 may be used to receive an image or sequence of images from imaging components 428, such as the image capture device.

[0055] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. The foregoing descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive of or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations are possible in view of the above teachings. The embodiments are shown and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents:

Claims

What is Claimed is:

1. A video frame sequence control system 100 comprising:

a switching component 102 coupled to a video source and a switch control signal, the video source providing analog video signals representative of a sequence of input image video frames, wherein responsive to the switching control signal the switching component 102 switches between signals representative of at least image video frames and crosstalk reduction frames, wherein the switch to the crosstalk reduction frame requires switching the voltage values of the analog video signals representative of the input image video frames to a voltage signal representative of the crosstalk reduction frame type; and

a video frame sequence control component communicatively coupled to the switching component and the switch control signal for providing switching component information regarding the frame type of the video frame to be output.

2. The video frame sequence control system recited in claim 1 wherein the switching component includes a plurality of voltage switching nodes, wherein each switch 124, 126, 128 in the switching component 102 includes at least one image voltage node and at least a first crosstalk reduction voltage node.

3. The video frame sequence control system recited in claim 2 wherein the switching component further includes at least a second crosstalk reduction voltage node.

4. The video frame sequence control system recited in claim 1 wherein the voltage level of the at least first crosstalk reduction voltage node is tied to ground.

5. The video frame sequence control system recited in claim 1 wherein the voltage level of the at least first crosstalk reduction voltage node is tied to voltage level of the white level signal.

6. The video frame sequence control system recited in claim 1 wherein the voltage level of the at least first crosstalk reduction voltage node is tied to an voltage node having an intermediate voltage level between the white and black level signal.

7. A method of outputting a video sequence including the steps of:

receiving analog signals representative of a sequence of input video frames from a video source 110 (step 310);

determining the frame types of the video to be output according to

information from an output video frame sequence control component 104 the frame types including at least input image video frames and crosstalk reduction frames (step 320);

responsive to the frame type of the output video frame sequence,

positioning the switch the switches 124, 126, 128 of the switching

component to connect to a node representative of the frame type (step 330); and

outputting the analog signal of the video frame associated with the node representative of the frame type.

8. The method recited in claim 7 wherein the switching component includes a plurality of voltage switching nodes, wherein each switch 124, 126, 128 in the switching component 102 includes at least one image voltage node and at least a first crosstalk reduction voltage node.

9. The method recited in claim 7 further including the step of transmitting a video frame output sequence signal 108 to the switching component 102 from the video frame sequence control component 104, wherein the video sequence output sequence signal 108 includes sequence information and timing information regarding the video frame sequence output.

10. The method recited in claim 9 wherein the sequence information includes

frame type information.

11.A non-transitory computer readable storage medium having computer

readable program instructions stored thereon for causing a computer system to perform instructions, the instructions comprising the steps of:

determining the frame types of the video to be output according to information from an output video frame sequence control component 104 the frame types including at least input image video frames and crosstalk reduction frames (step 320);

responsive to the frame type of the output video frame sequence, positioning the switch the switches 124, 126, 128 of the switching

component to connect to a node representative of the frame type (step 330); and outputting the analog signal of the video frame associated with the node representative of the frame type.

12. The computer readable storage medium recited in claim 11 wherein the switching component includes a plurality of voltage switching nodes, wherein each switch 124, 126, 128 in the switching component 102 includes at least one image voltage node and at least a first crosstalk reduction voltage node.

13. The method recited in claim 11 further including the step of transmitting a video frame output sequence signal to the switching component from the video frame sequence control component, wherein the video sequence output sequence signal includes sequence information and timing information regarding the video frame sequence output.

14. The method recited in claim 13 wherein the sequence information includes frame type information.