Abstract: A chromokeying system includes a store that contains a representation of a known coded chromokeying pattern. The system further includes a frame grabber that grabs a video image including at least a portion of the known coded chromokeying pattern and a foreground subject. A perspective transformation computation unit computes a perspective transformation by comparing the video image of the portion of the coded chromokeying pattern with the known chromokeying pattern. The system may further include a background generation unit that receives a background image and applies the perspective transformation to the background image to produce a transformed background. The portion of the coded chromokeying pattern in the video image can then be replaced by the transformed background to create a composite image.

Abstract: A system for producing multiple personalized video sequences of a subject includes a storage medium storing a foreground video sequence of an element of interest which has been pre-mixed to enable keyed superposition over an other video image, and a video camera for generating a background video signal corresponding to a real-time video sequence of the subject. A mixer superposes the foreground video sequence over the background video signal to produce a combination video sequence in which the subject appears together with the element of interest. A video monitor is provided for displaying the combination video sequence as it is mixed. The system may be constructed as an automated machine with an automatic payment system and a media recorder and feeder. Preferably, the system includes camera and lighting control systems for producing effects in the real-time video signal to mimic similar effects in the pre-recorded video sequence.

Abstract: A video signal compositing system uses advanced communication techniques to make compositing with virtual studio, blue screen, multi-color compositing, dynamic blue screen, add insertion, synthetic transfiguration, or panoramic displays more economical. A data communication system comprises a number of shared communications channels for transmitting data streams in a bi-directional manner. Multiple interface subsystems are coupled to the communications channels. The interface subsystems have a time slot controller that allocates time slots between the communication channels. A router is used in conjunction with the interface subsystems to define the time slots in which data on the shared communications channels are valid. Processing elements connected via the interface subsystem allow reconfiguration, via the shared communications channels, of processing operations performed.

Abstract: A picture replacement system for replacing a specified area of an original picture, with a desired picture comprising at least one camera for shooting an original picture of the subject; at least one irradiation unit for radiating a specified area of the subject with a predetermined invisible light ray; a picture generation unit for generating a desired picture that matches a size of the specified area; a detection unit for detecting the invisible light ray reflecting from the specified area that has passed around an obstruction in front of the specified area of the subject without being obstructed; a key signal generation unit for generating a key signal indicating a replacement area of the original picture based on a detection result of the detection unit; and a replacement unit for replacing the specified area within the replacement area with a desired picture corresponding to the key signal indicating the replacement area.

Abstract: The present invention is useful in taking a visible light image for identification and other purposes without the requirement of a photobooth, regardless of the background of the visible light image. The original background of the visible light image is replaced with a preselected background. Two IR images with different intensities of IR illumination in the foreground and background regions of the scene, respectively, are compared to produce a difference image of light intensity differences between corresponding pixels of the two images. A binarized image is generated by binarizing the difference image with respect to a predetermined threshold value .theta.. A connectivity constraint is used to generate a binary mask from the binarized image, then a gray-scale mask is produced by multiplying the binary mask times a preselected modulation function of the difference image. Warping the gray-scale mask produces a transformed mask.

Abstract: A video special effect generator comprises a first mixer supplied with an input video signal indicative of an input image, a delay circuit for delaying an output video signal supplied thereto from the first mixer and supplying a delayed output video signal to the first mixer, and a control circuit including an edge detecting circuit for detecting an edge of an input image indicated by the input video signal supplied thereto and outputting an edge signal indicative of the detected edge and generating a mixing ratio control signal on the basis of the edge signal, wherein the first mixer mixes the input video signal and the delayed output video signal supplied thereto from the first delay circuit with a mixing ratio based on the mixing ratio control signal.

Abstract: A video mixing apparatus for mixing a first video signal and a second video signal in accordance with a first key signal and a second key signal. The video mixing apparatus includes a key signal mixer for receiving the first and second key signals and generating and outputting a third key signal and a fourth key signal, wherein a level K.sub.1 of the first key signal, a level K.sub.2 of the second key signal, a level K.sub.p of the third key signal, and a level K.sub.m of the fourth key signal satisfy the relationships:K.sub.p =K.sub.2 -K.sub.1 K.sub.2,andK.sub.m =K.sub.1 +K.sub.2 -K.sub.1 K.sub.2 ;a key signal division section for receiving the third and fourth key signals and generating and outputting a fifth key signal, wherein a level K.sub.g of the fifth key signal satisfies the relationship:K.sub.g =K.sub.p /K.sub.

Abstract: Apparatus processes mixed YUV and color palettized video signals for display on an interlaced NTSC or PAL television receiver by storing first and second fields of one or more sprites in a graphic memory. Each sprite is stored as YUV or color palettized data and given a priority. A higher priority sprite overwrites pixel data of sprites of a lower priority when sprites overlap. First and second adjacent horizontal lines of pixel data in the first and second fields, respectively, are concurrently stored in respective first and second double buffers of a pixel assembly buffer during each line period. A delay buffer and the first and second double buffers generate first, second, and third adjacent horizontal lines, respectively, of pixel data at the output of the pixel assembly buffer while third and fourth adjacent horizontal lines of pixel data are inputted to the first and second double buffers.

Abstract: A background region of the current image is compared to a reference region to characterize the gain associated with the current image. The values of the unsaturated background pixels of the current image are then adjusted to correct for the characterized gain before encoding the current image. In a preferred embodiment, the reference region is generated based on the previous n frames in the video sequence.

Abstract: A method and a circuit for generating a composite video signal formed from a foreground signal and a background signal in accordance with the luminance self-key mode is described, in which the key signal is derived from the luminance foreground signal in dependence upon a clipping level. To avoid a quadratic dependence of the luminance signal during product formation of the key signal with the foreground signal (referred to as "double multiplication"), the linear key signal should be replaced by a control signal which is hyperbolically formed in such a way that the unwanted quadratic dependence is eliminated.

Abstract: A video special effect generator comprises a first mixer supplied with an input video signal indicative of an input image, a delay circuit for delaying an output video signal supplied thereto from the first mixer and supplying a delayed output video signal to the first mixer, and a control circuit including an edge detecting circuit for detecting an edge of an input image indicated by the input video signal supplied thereto and outputting an edge signal indicative of the detected edge and generating a mixing ratio control signal on the basis of the edge signal, wherein the first mixer mixes the input video signal and the delayed output video signal supplied thereto from the first delay circuit with a mixing ratio based on the mixing ratio control signal.

Abstract: The present invention is useful in taking images for identification and other purposes without the requirement of a photobooth, regardless of the background of the image. The original background of the image is replaced with a preselected background. Two IR images with different intensities of IR illumination in the foreground and background regions of the scene, respectively, are compared for light intensity differences between corresponding pixels of the two images to form a mask differentiating between the foreground and background regions of the image. The mask is then applied to a visible light image of the scene and the preselected background is used to replace the original background.

Abstract: A video signal mixing device for mixing a first video signal including at least a mutually related first signal component and second signal component and a second video signal which is made up of at least a mutually related first signal component and second signal component, for each of those signal components, the video signal mixing circuit including a differential signal producing means for obtaining a differential signal showing a difference of values of the first signal component of the first video signal and the first signal component of the second video signal and a mixer for mixing the second signal component of the first video signal and the second signal component of the second video signal by a mixing ratio determined based on the differential signal.

Abstract: In deriving a key signal for a digital mixer from an input video signal, most values of the key signal are derived by a clip and gain circuit. However, in the special case where the normalized product values for adjacent pixels lie on opposite sides of the upper and lower bounds, the following equations are used to determine the key values (K.sub.i and K.sub.h) for the two adjacent pixels:K.sub.i =0.5 (Ub-Lb)*[P.sub.b -0.5 (Ub-Lb)]/(P.sub.h -P.sub.i),K.sub.h =K.sub.i +0.5 (Ub-Lb),where Ub and Lb are the upper and lower bound values respectively, and P.sub.i and P.sub.h are respectively the lower and higher product values of said two adjacent pixels.

Abstract: A method and apparatus for raster-scanned video graphics systems where clocked digital video words from a plurality of sources are combined so that, at each video clock time, a word is chosen from one of the ports to light the current pixel on a display. There is an input port for each video source and a gate associated with each input port for passing or inhibiting a binary word. A decision at each video clock time chooses a word from one of the ports and passes it to an output port which leads to a video display or palette device. This decision is based on the data content of the current digital video words at the input ports.

Abstract: A color region extracting portion detects a specific color region from an input foreground image signal. A mapping portion categorizes an output signal of the color region extracting portion as a class. A high level resolution signal is generated with a predicting coefficient pre-learnt corresponding to the class. A threshold value Th is supplied from a terminal to a stretching portion. The stretch portion performs a stretching process. The stretching portion supplies a coefficient k as a key signal to a multiplier and a compensation signal generating portion. The compensation signal generating portion supplies a coefficient (1-k) to a multiplier. The multiplier multiplies the coefficient k by the coefficient (1-k) and outputs the result as a composite image of the foreground image and the background image.

Abstract: A method and an apparatus for substituting a representation of a target, identified by a set of points of interest stored in a memory, with a matching representation of a predetermined stored pattern in successive TV frames are described. The apparatus has a buffer for storing successive frames of a sequence, constituting a first in-first out memory having a length sufficient for storing all frames over a period of some seconds. Points of interest in each current frame are extracted and an attempt is made to find at least a subset of the extracted points of interest matching with a respective subset of the stored set. Global motion of the image between successive frames is evaluated and the location of the target in the frames following and preceding a frame in which the pattern is found is predicted. A target finder locates the target in the frames where it is found, based on the prediction.

Abstract: A method and system for combining digital data signals representing digitized images to implement a DSK operation in one mixing stage. The system requires only one mixing circuit, rather than two as in conventional DSK systems. In preferred embodiments, the DSK operation processes an input video signal having pixels a.sub.k, an input video signal having pixels b.sub.k, a stream of single-color pixels B, and a fade control signal .beta., to generate a stream of output pixels u.sub.k =(1-.beta.)v.sub.k +.beta.B, where v.sub.k =(1-.alpha.)a.sub.k +(.alpha.)b.sub.k, and .alpha. is a key signal which can have a different value for each pixel a.sub.k. The value of .alpha. can be constant for an entire frame of input pixels a.sub.k or can have a different value for each individual pixel a.sub.k. Typically, the value of .beta. is constant for each frame of input pixels a.sub.k. Preferred embodiments of the system employ a single mixing circuit, which receives five input data streams: first pixels a.sub.

Abstract: A method of producing a composited video image based on depth uses a serial combiner to which a plurality of video input signals, representing video images, and priority signals are input. The video input signals each have an associated depth signal. The depth signals are sorted from farthest to nearest and a matrix control signal is generated from the depth signals. The matrix control signal is used to route the video input signals to appropriate inputs of the serial combiner in order from farthest to nearest. The priority signals are derived from the depth signals either serially or in parallel.

Abstract: At least three video signals including at least one video signal which is given special effects are combined into a single video signal. Each of the three video signals contains a key signal and depth information. Two video signals closer to a viewpoint for images represented by the video signals are selected from the at least three video signals, per pixel, by comparing the depth information contained in the video signals per pixel to detect two pieces of depth information corresponding to two pixels closer to said viewpoint, and holding the two pixels corresponding to the detected two pieces of depth information based on the detected two pieces of depth information. Then, the selected video signals are weighted and mixed based on the key signals and depth information thereof per pixel.

Abstract: A circuit for analog chroma keying on color data permits display of graphics, generated from a computer system, and video on an output display. The analog chroma keying circuit receives the graphics signals and the video signals, wherein the graphics signals include color data to designate a color key. The analog chroma keying circuit includes a plurality of digital to analog converters that generate a plurality of color key limits for defining a range to detect the color data denoting the color key. The analog chroma keying circuit also includes a plurality of comparators coupled to receive the graphics signals and the color key limits for each primary color. The plurality of comparators generate a key on indicator when the graphics signals fall within the color key limits.

Abstract: A self keyer with background gap fill adds background video to the gap between the background video and a fill video resulting from self key error. The self keyer performs the general function:Composite=Fill*f(Key)+Background*(1-f(Key)*(Key))where f(Key) is a programmable transfer function used to generate a multiplication factor, f(Key), for shaping or reshaping the fill video and to generate a hole cutting signal, f(Key)*(Key), for shaping the background video. The shaped foreground and background videos are combined to generate a composite video. The transfer function may be generated and stored in a PROM/RAM buffer as a lookup table by a CPU. The transfer function may also be generated interactively by adjusting various points on the transfer function individually, with the CPU storing the resulting transfer function in the PROM/RAM buffer.

Abstract: A method of inserting a background signal (BG) into parts of a foreground signal (FG), which parts are fixed by a predetermined key color (KC), in which method a control signal (k) is derived from the foreground signal (FG), which control signal assumes a first value when the foreground signal (FG) represents a color in the region of the key color (KC) and a second value when the foreground signal (FG) represents a different color, in which the control signal (k) has a transition range between the two values, and in which a difference, influenced by the control signal (k), between the vector of the background signal (BG) and the vector of a signal (KC) representing the key color is vectorially added to the foreground signal (FG) in accordance with Patent (U.S. patent application Ser. No. P 41 43 180.4), as well as an arrangement for performing this method.

Abstract: In a method of and an arrangement for inserting a background signal into parts of a foreground signal fixed by a predetermined key color, in which a control signal is derived from the foreground signal, this control signal assuming a first value when the foreground signal represents a color in the region of the key color and a second value when the foreground signal represents a different color, and in which the control signal has a transition range between the two values, a difference, influenced by the control signal, between the vector of the background signal and the vector of a signal representing the key color is vectorially added to the foreground signal.

Abstract: A chroma keying device is provided for switching between graphics images and video images. An input signal and a reference are compared to provide a switching signal for performing the switching between graphics and video. A switching signal is provided when the input signal color information indicates that the input signal represents a true black image. Thus, switching is triggered upon black in the chroma keying device of a present invention. The black level is determined when each of the red, blue and green inputs of the device receives substantially zero current. A very sensitive comparison is performed between these input lines and a reference voltage in order to detect this condition. In the chroma keying device of the present invention, this sensitive comparison is accomplished using matched diodes within a common integrated circuit.

Abstract: A shaped video having an input key control signal associated therewith is processed by carrying out a first operation on the input key control signal to provide a first processed signal, carrying out a second operation on the first processed signal to provide a second processed signal, and combining the shaped video signal and the second processed signal to provide an output video signal. One of the first and second operations comprises translation. In this manner, a simulated shadow is added to the shaped video signal.