Abstract: A multi-dimensional data enhancement system can be embedded within a video cable for providing enhanced video images from a video signal source to a display. The multi-dimensional data enhancement system can also be provided in a switching box that allows a user to connect multiple video signal sources to the box and then select a particular video signal source from the group. The selected signal is then enhanced by the switching box before the signal is shown on a display.

Abstract: A method extracts an alpha matte from a video acquired of a scene. A set of pinhole or narrow aperture images IP is acquired of the scene with a camera aperture set to a relatively large depth-of-field. The scene includes a background B and a foreground F. A corresponding set of wide aperture images IF is acquired of the scene with the camera aperture set to a relatively small depth-of-field. The respective pinhole and wide aperture images are combined to extract an alpha matte according to ?=1+(IF?IP)/(B?BF).

Abstract: An image synthesizing apparatus is provided. The image synthesizing apparatus includes: a key image selector, a background selector, a key processor, an image synthesizer, a frame memory, a part designator, and a writing device. In the image synthesizing apparatus, the image signal that has been selected by the key image selector is sent to the key processor, the image signal that has been processed by the key processor is sent to the writing device and written into the frame memory, and image signals read from every storage region of the frame memory are sent to the image synthesizer.

Abstract: A method and apparatus of displaying an Electronic Programming Guide (EPG). In one embodiment, an EPG is constructed of a three dimensional virtual mesh, in which independent objects representing television programs are situated. The virtual mesh is displayed perpendicularly, so that the hardware requirements of the set top box (STB) may be reduced. A user can navigate the mesh to find television programs that they wish to view. A user can designate the types of television programs that they prefer, and these programs will be displayed more prominently. In addition, the mesh is constructed of at least two planes. The first plane is flat, while all other planes are hyperbolic to correct for a viewer's line of sight.

Abstract: A key signal control unit for controlling the level of a key signal corresponding to an arbitrary position within a frame area to a level corresponding to a minimum distance from an inner edge of the frame area on the basis of the level of a key signal on the inner edge of the frame area as a reference value so that the frame area appears along an outer circumference of an image corresponding to a video signal. A totally new image special effect is thus made on the video signal.

Abstract: Method and apparatus for combining a first video signal and a second video signal. The method comprising the act of replacing data in the second video signal with corresponding, in respect of a position within an image, data from the first video signal when said data in the second video signal represent a predefined repetitive pattern.

Abstract: An ? value in a desired shape in a desired position can be rewritten to a desired value in a desired range. ? value rewriting units for rewriting an ? value showing an opaqueness degree of an image are provided. When the desired position comes, an area setting signal is outputted in a desired shape from an area setting signal generating unit. While the area setting signal is being outputted, in the ? value rewriting unit, an ? value of inputted image data is rewritten to a desired value. The rewriting of the ? value can be dynamically realized independent of software. By preparing a quadrangular area calculating unit and a circular area calculating unit as an area setting signal generating unit, a quadrangular area and a circular area can be set by hardware.

Abstract: To allow a telop image to be displayed appropriately even when color information and transparency information for the telop image are transmitted over a network, the present invention provides a telop image sending/receiving system comprising a telop image sending apparatus and a telop image receiving apparatus in which the telop image sending apparatus has an OA fill signal input section for inputting color information for a telop image, an OA key signal input section for inputting transparency information for the telop image, an association storage section for storing color information and transparency information as a pair, a data compression section for compressing data, and a sending section for sending compressed color information and transparency information to a receiving apparatus, and the telop image receiving apparatus has a reception and storage section for receiving and storing the information, a data decompression section for performing data decompression, an OA fill signal output section for ou

Abstract: Apparatus for inserting an externally supplied video image into a computer graphics image. A TV card (131), responsive to synchronization signals, is connected to a video source to receive and convert an input video stream and also connected to provide a scaled and positioned video image (754) synchronized to a computer graphics image. A graphics card (150) is configured to provide the TV card (131), with a computer graphics image (652) having an embedded color key signal, video scaling and positioning parameters and horizontal and vertical synchronization signals. A window keyer (260) is connected to the TV card (131) and the graphics card (150) to provide the video stream and the computer graphics image to a computer monitor (170).

Abstract: A line image which comprises one line parallel to the juxtaposing direction of light-emitting elements is extracted from a three-time image, and a work region is determined, in which, in the juxtaposing direction, an M sub-pixel is added to the front side of the line image and an N sub-pixel is added to the rear side thereof. A background image of a region corresponding to the work region is read out from the frame memory. The read out background image whose precision is made the same as that of the three-time image in a pseudo state, and the line image are blended to obtain a blend image. Image data resulting from the blend image are written in a region corresponding to the work region of the frame memory. The above process is repeated for all lines of the three-time image.

Abstract: An example-based filling system identifies appropriate filling material to replace a destination region in an image and fills the destination region using this material, thereby alleviating or minimizing the amount of manual editing required to fill a destination region in image. Tiles of image data are borrowed from the proximity of the destination region or some other source to generate new image data to fill in the region. Destination regions may be designated by user input (e.g., selection of an image region by a user) or by other means (e.g., specification of a color or feature to be replaced). In addition, the order in which the destination region is filled by example tiles may be configured to emphasize the continuity of linear structures and composite textures using a type of isophote-driven image-sampling process.

Abstract: A video mixing apparatus carries out a chromakey process producing less degradation of picture quality by generating a key signal which separates a foreground object component from a screen component by using luminance information. In a three-dimensional color space, a smaller oval body surrounding a region where the foreground object is distributed and a larger oval body surrounding the smaller one are set. These two oval bodies and a distribution of a source video signal determine a key signal distribution. Key signal K=0 (zero) when the source video signal is inside the smaller oval body, and K=1 (one) when the signal is outside the larger oval body. 0<K<1 when the signal is between the smaller and the larger oval bodies. Based on the key signal K generated, the source video signal is mixed with the background video signal.

Abstract: An improved video production architecture adds an additional transition element for controlling external devices in synchronism with a given transition so that the transition is treated like a simple mix or wipe. The additional transition element is a “Trigger” function that has a value indicating when during the given transition the external device is activated. The trigger function, device controlled and trigger value are set up during preconfiguration of an effect in an effects memory. When the effect is recalled, if the Trigger function is activated on a switcher control panel, then the external device is activated at the time during the given transition specified by the trigger value.

Abstract: Disclosed is a device and method for realizing transparency. When a user requests a transparent function, a specific background color that is selected to be transparent by the user is identified in an OSD transparent mode and an image with YUV image data inserted instead of the OSD background color data is displayed upon receipt of the OSD background color data. In a YUV transparent mode, a specific background color that is selected to be transparent by the user is identified and an image with OSD image data inserted instead of the YUV background color data is displayed upon receipt of the YUV background color data.

Abstract: According to the signal processing apparatus of the present invention, in a text signal processing circuit, predetermined signal processes are executed to a luminance signal Y and color difference signals U and V in which a ratio of sampling clocks is equal to (4:4:4) and resultant signals are supplied to a mixing circuit. In a video signal processing circuit, predetermined signal processes are executed to the signals Y, U, and V in which a ratio of sampling clocks is equal to (4:1:1) or (4:2:2). The signal Y is supplied to the mixing circuit through a delay adjusting circuit and the high frequency components are removed from the signals U and V by a band limiting filter and, after that, the resultant signals are supplied to the mixing circuit. The signal mixed by the mixing circuit is supplied to a LPF through a D/A converter. In the LPF, the signal is demodulated by the band limiting filter according to (4:4:4).

Abstract: Upon chromakey processing, 4×4 transformation matrix is provided through which a backing color selected is transformed to the original point and monochrome color is transformed to vertically distribute at a spot away from the original point along an axis. Matrix multiplication comprising only addition and multiplication is applied to a foreground image data signal to generate a masked output image and a color-processed foreground output image without requiring complex arithmetic operations.

Abstract: A system and corresponding method for head tracking and color video acquisition via near infrared luminance keying is disclosed. The head of the local user is tracked in real time by uniformly illuminating a rear projection screen that surrounds a display cube with light having a wavelength in the near-infrared spectrum. A near-infrared image of the head of the local user is acquired by a near-infrared camera equipped with filters that discern the difference between the illuminated rear projection screen and any foreground illumination. A color image of the head of a local user and the projection of a remote location are acquired by a color camera, placed in close proximity to the near-infrared camera. A bounding box is then placed around the head of the local user in the near-infrared image. This bounding box is then translated to the view space of the color camera. This translated image is then used to crop the color image. The cropped color image is then transmitted to the remote location.

Abstract: A video processor produces video and key signals to be processed by a television production switcher for superimposing text or the like on a background image. The video processor has a key generator for receiving an input video signal and an input key signal and selecting one of these signals and shaping waveforms of the selected signal. Responsive to a first control signal, the input video signal is stored in a first frame memory and read during a later frame interval. Responsive to a second control signal, the output signal of the key generator is stored in a second frame memory and read during a later frame interval. A delay time corresponding to the processing time of the key generator is introduced to the input video signal. A first switch selects one of the outputs of the delay circuit and the first frame memory, and a second switch selects one of the outputs of the key generator and the second frame memory.

Abstract: The present invention provides methods and apparatus to distinguish and/or separate an object from a background. The methods use backgrounds of known and/or advantageous texture. In an embodiment, a measure of image texture, namely the spatial frequency is used to distinguish and/or separate an object from its background. The use of image texture overcomes limitations of chroma keying used as a processing technique in photography for object-background separation. This is useful in the separation of image pixels belonging to the object of interest from image pixels belonging to the background.

Abstract: Creating a transition between a first sequence of video frames and a second sequence of video frames. The method includes storing a table of values that express a non-linear response to certain levels of light, generating a transition between the sequences, and adjusting the intensity at which material of the first sequence is displayed relative to the intensity at which material of the second sequence is displayed within the transition, based on the values stored in the step of storing.

Abstract: The color-keyed regions of a color-keyed image are extracted from the color-keyed image, and the color-keyed regions and the non-color-keyed regions are independently scaled. The independently scaled regions are subsequently merged to form a scaled color-key image with clearly distinguished color-keyed regions and non-color-keyed regions. To minimize the blurring of edges in the non-color-key regions, the non-color-key colors are extended into color-keyed regions after the color-keyed information is extracted from the color-keyed image. To minimize the encroachment of the scaled color-keyed regions into the scaled non-color-keyed regions of the scaled color-key image, the edges of the scaled color-key regions are sharpened by defining the color-keyed region as the region wherein each scaled/filtered color-key value exceeds a non-zero threshold value. To facilitate the use of existing memory and structure in images that are encoded using three components per pixel, such as RGB, YUV, etc.

Abstract: The present invention provides an image compositing apparatus capable of producing a natural composite image, with a simple structure and a less occupying space. The present invention also provides a method for compositing an image by providing shadow-free conditions in a limited space for chroma-keying so that a subject image and a desired background image are naturally integrated as one image.

Abstract: The present invention is a method and apparatus for automatically defocusing a background scene as the background scene is being composited with a foreground subject during the photography of the subject, where the background scene becomes increasingly defocused as the subject appears to approach the camera. A source of background image signals is connected to a background input of a compositing device capable of averaging a selected group of background pixels. A source of foreground image signals is connected to a foreground input of the compositing device. A matte signal generated by the compositing device is accessed and the matte signal is used to determine the ratio of foreground subject area to image frame area. The area ratio is then used to select, for each pixel in said background image, a number of adjacent pixels to be averaged to form an average pixel level. The signal levels at each pixel in the background scene are replaced with the average pixel level.

Abstract: Video signal processing apparatus in which at least two input video signals are combined in proportions determined by a pixel key signal to generate an output video signal for compression, at least one of the input video signals each having respective associated compression parameters from a data compression process applied to that video signal. The apparatus functions to estimate the quantity of data which will be produced by compression of a current image of the output video signal, compares the detected quantify of data with a target quantity of data, to determine whether a data overflow is expected, and in the event that a data overflow is expected, determine which blocks of the output video signal can be compressed by re-using compression parameters from corresponding block of one of the input video signals.

Abstract: A video processing device and method receives data from a common data source, such as a frame buffer and outputs first overlay information in a first color space from a first port and outputs second overlay information in a second color from a second port to facilitate output of multiple overlay images in different color spaces from common memory through different ports. In one embodiment a bidirectional port is used to allow a set of common signal pads or a bus to function as a flexible bidirectional video data port.

Abstract: A method and system for triggering, composing, and displaying presentations of a live event, such as a sporting event. Prior to the event, data characterizing a set of triggering events and data characterizing a set of layout rotations is stored. Each layout rotation includes one or more layouts, and each of the layout rotations is associated with one of the triggering events. During the live event, instances of the triggering events are detected, at which time the associated layout rotation is automatically initiated.

Abstract: Video signal processing apparatus in which at least first and second input video signals are combined to generate an output compressed video signal, the first and second video signals each having respective associated motion vectors from a data compression process applied to the video signals; comprises: means for establishing a set of the motion vectors associated with the first and second video signals which can potentially be re-used in compressing the output compressed video signal; and means for testing the set of motion vectors, the testing means being operable: (c) to define, with respect to reference images referred to by the motion vectors under test, a first border region of a predetermined width surrounding those parts of the reference images derived in part from the first video signal, and a second border region of a predetermined width surrounding those parts of the reference images derived in part from the second video signal; and (d) to test whether motion vectors of the set which are assoc

Abstract: The color-keyed regions of a color-keyed image are extracted from the color-keyed image, and the color-keyed regions and the non-color-keyed regions are independently scaled. The independently scaled regions are subsequently merged to form a scaled color-key image with clearly distinguished color-keyed regions and non-color-keyed regions. To minimize the blurring of edges in the non-color-key regions, the non-color-key colors are extended into color-keyed regions after the color-keyed information is extracted from the color-keyed image. To minimize the encroachment of the scaled color-keyed regions into the scaled non-color-keyed regions of the scaled color-key image, the edges of the scaled color-key regions are sharpened by defining the color-keyed region as the region wherein each scaled/filtered color-key value exceeds a non-zero threshold value. To facilitate the use of existing memory and structure in images that are encoded using three components per pixel, such as RGB, YUV, etc.

Abstract: A teleconferencing system in which the video image of a subject in front of a selected background scene is extracted from that scene and transmitted to other locations where selected backgrounds are stored. By compositing the subject and background images at each remote location, both image elements, being originals, will show no loss of detail when projected. For a front projection screen, the projector is inhibited from illuminating a presenter.

Abstract: A system for generating a variety of solid signals and key signals. The system includes a multiple of solid generators, a multiple of key signal generators and a cross-point switch. Each of the solid generators includes a multiple of solid mixers, and each of the key signal generators includes a multiple of key signal mixers. The cross-point switch is arranged to connect any of the solid generators and key signal generators to any of the switch's main outputs, and to connect any of the solid generators to any of the key generators. The system provides for selection of preset delays to compensate for different signal routings. A timing control controls routing and delay selection.

Abstract: A color conversion apparatus in which an output result of a color converting circuit at a succeeding stage for color-converting a specific color can be prevented from being affected by an output result of a color converting circuit at the preceding stage for color-converting a whole image. A first color converting circuit color-converts a whole image of image data in a first color-conversion fashion. A second color converting circuit color-converts only the area of such color in a second color-conversion fashion by adding a correction signal which results from multiplying a key signal indicative of an area of specific color to image data in which the whole image is color-converted in a first color-conversion fashion. A key signal generating circuit generates the key signal from the image data supplied to the first color converting circuit.

Abstract: Apparatus for producing a composite image from a foreground image (FG), showing an object or a scene with a substantially monochrome background, and background image (BG) comprising a first processing unit (R4) for producing a control signal (SEP) for each pixel of the foregoing image (FG), reflecting whether an individual pixel of the foreground image is part of the object or part of the monochrome background, based both on the chromatic values of the pixel and on predetermined chromatic values, describing the color composition of the monochrome background, a selection unit (R5) suffixed to the first processing unit (R4), for calculating the chromatic values of an individual pixel of the composite image from, depending on the control signal (SEP), either the chromatic values of the corresponding pixel of the foreground image (FG) or the chromatic values of the corresponding pixel of the background image (BG), a second processing unit for calculating correction values for the chromatic values of an individual

Abstract: An image processing system which efficiently generates a desired special effect with a simple circuit. In order to add special effects to a given source picture, a target area specifying unit first specifies a target area, as part of the given source picture, which is to be subjected to a special effect generation process. The source image is coded by an image data coding unit, and the resultant coded data is then modified by a target data relocation unit, Here, part of the coded data, or target data in the target area, is extracted and relocated from its original field to a different field of the coded data. An image data transmission unit transmits the coded bitstream which contains the relocated target data. At the receiving ends, a target data extraction unit extracts the target data from the received coded bitstream, which is then saved into a target data storage unit.

Abstract: A special effect image generating apparatus provided with an image conversion processing circuit for posterization or other image conversion, a luminance and chroma condition setting circuit for image extraction by luminance and colors, a mask pattern generator for selection of a mask, and mixer for preparing a video signal, a transformation unit for transformation processing such as movement, and a post video modification unit for addition of a locus etc. The extracted image automatically tracks movement of the image so there is no change in visual effects, images having the same luminance and color conditions can be deleted by mask adjustment, movement of the image can be handled by adjustment of the mask, and highly accurate boundaries can be set by the wave-filtering and shaping circuit. Therefore, a special effect image with distinctive luminance and color can be easily prepared.

Abstract: A reference picture being as a reference of the replacement area, the reference position of the replacement area and the size of the replacement area has been memorized. Moreover, a replacing LOGO picture has also been memorized. A two dimensional movement amount of a camera is detected by a rotary encoder set on the pan head of the camera, and the detected movement amount is outputted as a movement information. In the picture synthesis device, an address of the reference position of the replacement area in the present picture is calculated based on the movement information, and the replacement area is detected with this address as reference. Then, a key signal indicating a picture in which the present picture and the reference picture within the replacement area are identical or different, and an identical portion between the present picture and the reference picture is replaced with a LOGO picture corresponding to the foregoing identical portion out of the LOGO picture based on this key signal.

Abstract: A method of determining the position of a TV camera relative to a patterned panel being viewed by the TV camera including the steps of: identifying a plurality of edge points of the pattern from the video signal produced by said camera and using these edge points to calculate the perspective of the pattern relative to the camera.

Abstract: To enable interlacing edge-generating means to be used for a progressive image signal that is separated into lines as two sequences of signals, the present invention comprises a pre-edge processing circuit (11) that executes appropriate pre-edge processing on the progressive image signal separated into lines depending on the condition of each of the two signals, and an edge generating circuit (18, 19) that executes on the two signals after pre-edge processing pre-edge generation processing similar to that for interlacing.

Abstract: A chromokeying panel for use in conjunction with a chromakeying system includes a plurality of first and second location. Each of the first and the second locations has a color within the color of a color keying spectrum of the chromakeying system. In addition, each of the first and the second locations are arranged to define a coded pattern for a computation of a perspective of the chromakeying panel with respect to a camera independently in each video field produced by the camera. The coded pattern may include a plurality of straight lines that intersect to define vertices. The plurality of straight lines may be spaced apart from each other so that for a given vertex, a ratio of the distance of one of the lines extending from the given vertex to a first adjacent vertex, to the distance of another of the lines from the given vertex to a second adjacent vertex is unique.

Abstract: An image processing system 11 is arranged to produce data representing a combined image from foreground data F representing a foreground subject in front of a chroma backing and background data B representing a background image. The foreground data is processed and color corrected to produce first and second processed foreground data which is combined in a combiner 25 under the control of a first key K1. The background data is processed using a second key K2 to “cut” a “hole” in the background image. The processed background data and the combined foreground data are added together in an adder 44. A third key K3 is used to remove unwanted data from the added foreground and background data and to combine the resulting data with the processed background data in a combiner 45.

Abstract: Combining first and second video streams into a combined output video stream by using a gradient table listing gradient values for pixels in a video frame to address a look up table of key values, and combining pixel values of the first and second video streams based upon respective key values read from the look up table.

Abstract: An image signal processing apparatus is provided and includes a YC separator circuit for extracting a chrominance signal from an image signal, a signal level detector circuit for outputting a signal level detecting signal by detecting a signal level of the chrominance signal and a signal level corrector circuit for correcting a signal level of the signal level detecting signal to generate a key signal according to the chrominance signal, the signal level corrector circuit including an oversampler circuit.

Abstract: A device and method for generation of digital advertisement displays in real time in digital TV-transmissions. In such digital TV-transmissions, a digital coding of the image material is made before the transmission is made; this coding compresses the content of the image as much as possible to minimize necessary bandwidth utilization at transmission of the signals. In connection with this coding and by means of pattern recognition, different patterns are identified for predefined objects in the image material, such as for example identifying an object with an unique coloring. Via the pattern identification, the image coder obtains information via a table of what the original object looks like. Also included in the table is information about which advertisement display is to be placed inside the identified object.

Abstract: A position detecting device for an object with virtual set comprises providing the object with an emitting device and using the device in conjunction with a plain or patterned chroma-key background to provide the exact position of a TV camera or alone to provide a position for another object or actor.

Abstract: A method for merging real and synthetic images in real time is comprised of the steps of providing a first signal containing depth and image information per pixel about a real image. A second signal containing depth and image information per pixel about a synthetic image is provided. The depth information corresponding to the real image and the depth information corresponding to the synthetic image for each pixel are compared. Based on the comparison, either the image information corresponding to the real image or the image information corresponding to the synthetic image is selected and combined.

Abstract: A color feature extracting apparatus is provided, which can easily transform a RGB color space into a color space close to the human sense and execute color classification and color region distinction of a digital image in the transformed color space. RGB values of each pixel of a digital image are transformed into HLS values by a color space transforming section. A hue value and a luminosity value of the HLS values are corrected by a hue correcting section and a luminosity correcting section, respectively, so that a region between a green color and a yellow color in a direction of hue and a region between the green color and a light blue color in the direction of hue are narrowed and a region between a red color and the yellow color in the direction of hue is widened in a color space represented by the HLS values. Then, the color features of the digital image are extracted by a color feature extracting section on the basis of the corrected hue value and luminosity value.

Abstract: In this invention, when the portion from which a key signal .alpha. is to be generated of picture is caused to be foreground F, the portion except for the above is caused to be background B, and pixel value of pixels constituting that picture is designated at C, the key signal .alpha. is generated so as to satisfy the relational expression C'=(F-B).alpha.'('(prime) represents differentiation). In more practical sense, a change detecting section 10 calculates change C' of pixel value between pixels constituting picture, and an F-B detecting section 30 calculates difference F-B between the foreground and the background. In addition, an integral value calculating section 40 divides the change C' by the difference F-B to integrate the result obtained by divisional operation to thereby determine key signal .alpha.. As a result, precise key signal can be obtained in this invention.

Abstract: A corner detector capable of detecting each corner position of a predetermined area from an input signal with a simple structure. There is provided memory means (9B) for storing memorizing an input signal (keyT) and corner detection means (9C) for detecting a point where the signal level becomes the reference signal level or more at first by reading an input signal stored in the memory means sequentially in horizontal direction from an upper limit and a lower limit of a retrieval scope and in vertical direction from the left end to the right end of the retrieval scope, and detecting a point where the signal level becomes the reference signal level or more at first by reading an input signal stored in the memory means sequentially in a diagonal direction at a predetermined angle from each angle of the retrieval scope to detect from the detected points four points whose positions differ.

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: An efficient chroma key-based coding technique for digital video with an optimized switching threshold. An optimized binary keying threshold is provided for switching between a first image region (such as a background region) and second image region (such as a foreground object) video picture. The threshold optimizes a PSNR of a quantization error Q of a key color K. A chroma key technique is also provided for representing the shape of a video object, where the shape information (alpha plane) of a foreground object is embedded in the keyed output, so there is no need to carry an explicit alpha plane, or use alpha plane coding. The chroma key shape representation technique provides a smooth transition at the boundary between objects without the need for special switching patterns, such as a general gray scale shape coding tool, or post-processing, e.g., using feathering filters.

Abstract: A digital video effects system for producing live-action video effects in real time includes an address generator having a pair of 2-D tables for providing x-coordinate and y-coordinate offset values. A third 2-D table contains warp activation factors (activators) which are scaled by a clip and gain processing technique to produce scaled activators. The scaled activators are used to scale the x- and y-offset values which are then combined with the original raster-order addresses to produce frame buffer readout addresses. An output video signal is produced by an inverse mapping of the input frame buffer to the output. The 2-D tables provide control of the image on a pixel-by-pixel basis. The degree of scaling by the clip and gain unit varies with time so that the resulting readout addresses also vary with time. A video effect, therefore, is produced simply by adjusting the scaling of the clip and gain unit. Moreover, a variety of effects can be achieved simply by changing the various 2-D tables.