Abstract: A visible luminance step in a background scene, caused by a signal level mismatch between a matte signal level and a blue backing signal level, is significantly reduced by a soft edge transition region that raises the blue backing signal level up to the signal level of a garbage matte by using a cleanup signal restricted to the transition region. The soft edge formed by cleanup does not make subjects transparent, and actors may enter this zone with little loss of image quality.

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: A method for automatically implementing and coordinating the techniques of creating the illusion of illumination changes on a foreground subject that should occur when the subject moves throughout the various illumination levels on the background of a composite image.

Abstract: An objectionable outlining effect, seen as dark edges and white edges outlining everything in a scene, is eliminated by clipping or limiting the spikes generated by excessive enhancement. Specifically, a method is used for improving the quality of an enhanced video image, while simultaneously maintaining or improving image sharpness, by clipping the RGB levels of the enhanced video image, at the points of enhancement, to upper and lower level bounds representing the signal levels of the video signal prior to its enhancement.

Abstract: In an image being displayed on a monitor, each observed background color is identified using a cursor to select the dominant colors. Each foreground color is also identified by using the cursor as a selector. For each pixel, several Candidate mattes are computed one for each background color. Each Candidate matte is computed from a single background color and the set of selected foreground colors using any known method. Of the several Candidate mattes, the greater of these Candidates becomes the matte signal for a given pixel. If this matte is 1.0, then the pixel is part of the background. If the matte is zero, then the pixel is part of the subject. If the matte is between 1.0 and 0.0, then the pixel is in a transition area and the contribution of the background to the pixel is that pixel's matte level. A ‘Processed Foreground’ is generated by removing the contribution of the background from each pixel in the image, resulting in the subject appearing against a black field.

Abstract: In most cases, the estimated subject color and/or the estimated background color for a given pixel will have a certain amount of error, which could result in either not enough background removal, or removal of all of the background and some of the foreground. By manually or automatically altering the estimated subject color and/or background color, the errors in matte calculation and subsequent removal of the background, can be minimized or eliminated. Manual alteration of a subject or background color is achieved by using a cursor to select a true color from the background, for example, and inserting it in one or more areas in the background area being partially obscured by the subject. Automatic alteration of one of the estimated subject or background colors involves its computation as a projection in color space of the observed transition pixel color, onto a plane defined by the subject and background reference colors or other defined planes.

Abstract: A method of removing the foreground subject and its shadow from a series of image frames including a subject before a colored backing being photographed by a moving camera during a live broadcast. Such removal results in a series of image frames of the colored backing without the subject, each image frame corresponding to an image frame containing the subject. The method steps employed identify, for each frame, those pixels in the frame occupied by elements of the subject. Those pixels are set to an RGB level of zero, to create an image of the colored backing in which the subject area is reduced to black. The image of the colored backing is then smeared to obliterate the defined edges of the subject's shadow and to smear the color of the backing into the black area previously occupied by the subject to generate a clear frame.

Abstract: The invention utilizes the fact that anyone with normal color vision has the ability look at a scene on a video display and recognize a black area if one is present; a white area if one is present, and face or flesh areas if a person is present. It is also easy to recognize blond hair, subjects that are opaque, subjects that are semi-transparent, and subjects that are bright green. The aforesaid abilities to recognize luminance and color characteristics of elements within a video scene are used in conjunction with the invention to produce ideal composite images by utilizing of a set of equations that incorporate a knowledge of color science, of video and existing compositing techniques. These equations are used to make adjustment decisions to produce the best possible composite image. The equations are used to compute certain constant values utilized in the existing compositing techniques.

Abstract: A method and apparatus used in the field of image compositing which eliminates the need to obtain an original clear frame of the backing during production, by synthesizing during post production a clear frame of the backing from a frame of the foreground scene that includes the subject as well as the backing. This synthetic clear frame eliminates the problems of obtaining a registered clear frame during production, and thereby permits the ready application of nonuniformity correction to image compositing in both motion pictures and graphic arts. The invention is also directed to a method and apparatus used in the field of image compositing which reduces the processing time for developing the inhibit signal that prevents the corrections from being applied to the subject, the control signal E.sub.c, and a number of other functions that are computed from the colored backing.

Abstract: The invention is a method used with a system for compositing a foreground scene including a subject before a nonuniformly illuminated colored backing, and a background scene, and where the nonuniformity is nonlinear from side to side and/or nonlinear from top to bottom. A window is employed to mask unwanted areas outside of, or on, the colored backing and one or more window edges form a visible join line where the window edges join the backing. The visible join line is made nonvisible without affecting the subject by a horizontal and vertical linear interpolation method for obtaining backing corrections that cause the backing level control signal to be uniform at the window edges and match an assigned window signal level.

Abstract: A method and apparatus which allows different amounts of filtering to be applied to specific parts of a foreground image, thus minimizing visible noise in the backing area, while preserving fine detail information of foreground objects. The method and apparatus identify three areas within the foreground, namely unobscured backing (screen) area, screen to foreground subject transition area, foreground subject area. The area where full amount of filtering is desired is the backing area, including shadows. This is the area where the background image will be added, and if noise is present in this area, it will be added to the background image. The transition area from the screen to the foreground object requires variable amounts of filtering, depending on the width of the transition. For sharply focused edges and very fine detail, the transition width is very small, and any filtering applied there will cause blurring and softening of these edges and details. Therefore, no filtering is applied to those areas.

Abstract: A method and apparatus used in the field of image compositing which eliminates the need to obtain an original clear frame of the backing during production, by synthesizing during post production a clear frame of the backing from a frame of the foreground scene that includes the subject as well as the backing. This synthetic clear frame eliminates the problems of obtaining a registered clear frame during production, and thereby permits the ready application of nonuniformity correction to image compositing in both motion pictures and graphic arts. The invention is also directed to a method and apparatus used in the field of image compositing which reduces the processing time for developing the inhibit signal that prevents the corrections from being applied to the subject, the control signal E.sub.c, and a number of other functions that are computed from the colored backing.

Abstract: A linear image compositing system which corrects for nonuniform luminance and/or color of the colored backing without incurring the penalties of edge glow, edge darkening, loss of edge detail and other anomalies. A control signal is created directly proportional to the luminance of the colored backing and controls the level of the BG scene. Unless the control signal is corrected, the background scene will contain all the brightness and color variations occurring on the colored backing. Correction factors are developed by comparing the RGB video obtained from the backing before the subject is put in place, with the ideal values of RGB that would have been obtained from a perfect backing. These correction factors correct the RGB video when the scene is scanned with the subject in place. The control signal, being zero in the subject area, may be used to inhibit the corrections in the subject area.

Abstract: A method and apparatus to improve the control signal E.sub.c used in a video image compositing system so that the adjustment to achieve an E.sub.c of just zero for green objects and flesh tones, does not simultaneously reduce E.sub.c in grey scale subjects and cause print-through. The invention also reproduces a wide range of blue colors from pale blue to bright blue in the presence of a blue backing without raising a matte density control and without raising noise level. The invention also provides a second control signal, E.sub.k, that eliminates backing color spill from blond and brown hair, without affecting bright foreground white tones. The invention also generates a SHADOW CLEAN-UP signal that eliminates foreground shadows, while preserving most of the foreground detail information.

Abstract: A system which allows the weather television personalities to move and place computer generated symbols onto a weather map background image using only his hand or finger as a pointing device. The weather forecaster is generally in front of a blue screen and must make it appear that he can actually see the weather map behind himself. In the video frame, which is raster scanned, the hand pointing to the object to be moved or placed translates to the first object in the raster (on the left) or the last object in the raster (on the right). The present invention is a method and apparatus which identifies the rightmost or leftmost point in the raster and communicates this information to a graphics computer as x-y coordinate data. The data is utilized by the computer to place a movable graphic symbol at the weather forecaster's fingertip allowing him to move and place the symbol.

Abstract: An apparatus and method which control the gain of the key signal dynamically and thereby compensate for the effects of an unevenly lit backing or lens vignetting. This dynamic control occurs over a video frame and has the effect of modulating the key signal. In this connection, there are four possible gain controls as follows: a) a horizontal ramp to increase the level of either side (left or right) of the key signal; b) a vertical ramp to increase the level of the top or bottom of the key signal; c) a horizontal parabola to raise or lower the gain of both sides of the key signal simultaneously to nullify lens effects; and d) a vertical parabola to raise or lower the gain of both the top and bottom of the key signal simultaneously to nullify lens effects.

Abstract: A man to machine interface for the control of video or motion picture camera movement for use with a camera aiming system which can reproduce a specific camera movement any number of times. The interface moves the camera in the pan or tilt axis giving an operator a natural control feel while actually driving the camera movement with a motor drive. A shaft encoder detects the velocity of the motor drive and stores such information over time in a memory. The data stored in the memory may be read out at a later time and used by the motor drive to replicate the movement of the camera.

Abstract: In the present invention, certain improvements are incorporated that permit removal of the backing color when its illumination is of non-constant color. In addition, an improved color logic is described that improves the simultaneous reproduction of fleshtones and green foliage in the same scene. A modified control logic is described that improves reproduction of red objects and fleshtones. A reversed window permits retention of objects whose color is identical to that of the backing. And, finally, a circuit is described which permits a super-imposing of titles or glow where said titles or glow may be made wholly transparent, semi-transparent or opaque.

Abstract: A method and apparatus to cause a colored backing to be replaced by a background scene, such that the composite scene shows no loss of detail, no edge anomalies, no evidence of a colored backing having been present, and no evidence that the final scene is a composite, even when the foreground scene contains fine strands of hair, glassware, smoke, fog, or other semitransparent subjects. Control signals E.sub.b and E.sub.c are created to cause the foreground and background scenes to mutually interact in a natural manner, so that shadows on the colored backing appear as shadows on the background scene, and the luminance of the background selectively causes back and edge lighting of foreground subjects. The hue and luminance of the colored backing are continuously and automatically tracked and removed by a subtraction process. The background level is automatically held constant even though backing illumination changes.