Abstract: A projector determines horizontal and vertical tilt angles. Using the tilt angles and the inherent properties of the projector, keystone correction corner points for the image can be computed. The keystone correction corner points can be used to perform keystone correction on the image.

Abstract: I describe and claim a temporal comb filtering system and method. The temporal comb filter system includes a comb filter to temporally process separated luminance and chrominance components from an image field responsive to image data from at least one other image field and a panel to display the processed components. The comb filter includes a cross-chroma detector to detect luminance information within chrominance data from a first image field responsive to chrominance data from at least one other image field and a cross-luma detector to detect chrominance information within the luminance data from the first image field responsive to the luminance data from at least one other image field.

Abstract: We describe and claim television channel change picture-in-picture circuit and method. The circuit includes means for displaying a first channel on a primary portion of a screen, means for changing from the first channel to a second channel, and means for displaying the second channel on a secondary portion of the screen responsive to the means for changing from the first to the second channel while continuing to display the first channel on the primary portion of the screen.

Abstract: We describe a weighted absolute difference based deinterlace method and apparatus. The deinterlace method and apparatus uses weighted absolute differences along different directions as means for interpolating pixel data using edge orientation detection. The apparatus includes a memory adapted to store a current and previous fields and predetermined portions of a future field of an input signal. A motion detector is adapted to detect motion between the future and previous fields. An interpolating circuit is adapted to generate a plurality of output pixels using a corresponding plurality of methodologies. And a switch is adapted to select between the plurality of output pixels responsive to the motion detector.

Abstract: A method and system for performing fuzzy logic based de-interlacing on film source fields that might be mixed with video on film. An embodiment of the invention comprises an adaptive de-interlacer by weighing between merge operation and interpolation operation in the case of occurring video on film motion object. A weighing factor is generated from video on film pattern based on fuzzy logic inference rules. This weighing factor specifies the weighting between merging and interpolating in assigning the pixel values of the progressive display output.

Abstract: We describe and claim a film mode judder elimination circuit and method. A film mode detector detects a film mode in a video signal. A judder eliminator eliminates judder by dynamically transitioning from one field rate, e.g., 60 Hz, to another field rate, e.g., 48 Hz or 72 Hz, responsive to the detection. The transition between the one and another field rate may occur during the vertical blanking period to avoid flicker.

Abstract: To interpolate a value for a pixel, multiple patterns are selected. Each pattern is used to determine a pixel angle. One of the determined pixel angles is then selected based on the reliability of the pixel angles. The selected pixel angle can be selected based on its reliability irrespective of the reliability of other pixel angles. The selected pixel angle can then be used to interpolate a value for the target pixel. Dynamic thresholds can be computed for use in either determining a pixel angle for a given pattern, or to select the pixel angle from the available determined pixel angles.

Abstract: A software implementation of a Reed-Solomon decoder placing a constant load on the processor of a computer. A Berlekamp-Massey Algorithm is used to calculate the coefficients of the error locator polynomial, a Chien Search is used to determine the roots of the error locator polynomial, and a Forney Algorithm is used to determine the magnitude of the errors in the received digital code word. Each step is divided into m small tasks where m is the number of computational blocks it takes to read in a code word and the processor can pipeline or parallel process one task from each step each time a block is read.

Abstract: The invention relates to a multiplexed video digitization system and method. The system includes a plurality of analog video signals, a multiplexer to select one of the plurality of analog video signals, and an analog-to-digital converter to convert the selected analog video signal into a digital video signal. The plurality of analog video signals may include component video signals, red, green, and blue signals, or s-video signals. The multiplexer may include control logic to select the one of the plurality of analog video signals. The system may include a plurality of sample and hold circuits to insure time aligned sampling of the corresponding plurality of video signals.

Abstract: A boost table stores adjusted target levels for pairs of original and target pixel levels. The adjusted target levels can be used to as a substitute for the target pixel level to improve pixel response in reaching the desired target pixel level. A reduced boost table can be used, storing a subset of the adjusted target levels. Fuzzy logic control rules can be used to calculate adjusted target levels not actually stored in the reduced boost table.

Abstract: We describe a keystone correction system and method. A vertical scalar vertically scales an input image and stores the results to a line buffer. A horizontal scalar retrieves the stored results from the line buffer and horizontally scales the stored results using the relatively small number of lines from the line buffer. The system repeats the vertically scaling, storing, and horizontal scaling until it processes all input image lines.

Abstract: A compressed pixel level for a pixel in a frame of an image is compared with the (compressed) pixel level for the same pixel in a previous image frame. If the pixel level is unchanged, then the pixel is not moving. An uncompressed pixel level is then used for that pixel in the current image. If the pixel level is changed, then the pixel is moving, and a decompressed, boosted pixel level is used for that pixel in the current image.

Abstract: We describe and claim a fuzzy logic based adaptive Y/C separation system and method. The fuzzy logic based adaptive Y/C separation system includes an adaptive Y/C separator to use fuzzy logic to separate chrominance data in a video signal, and a panel to display the chrominance data. The adaptive Y/C separator includes a plurality of filters, each to separate chrominance data in a video signal, and a blending circuit to use fuzzy logic to blend the chrominance data.

Abstract: The invention relates to a system and method for visually displaying data and, more particularly, to a system and method for displaying full screen high frequency data on a flat panel without using a frame buffer. The system and method displays a full screen, color, image that allows a user to adjust its computer back to a correct setting. That is, to exit the high frequency mode that produced the high frequency digital data in the first instance without having to connect a CRT, reboot, or the like. The system and method drives the panel's rows and columns so as to display interlaced data, thereby reducing the effective vertical frequency of the data. Because the human eye is incapable of perceiving the blank lines, the screen appears complete just as it does in the normal mode.

Abstract: A boost table stores adjusted target levels for pairs of original and target pixel levels. The adjusted target levels can be used to as a substitute for the target pixel level to improve pixel response in reaching the desired target pixel level. A reduced boost table can be used, storing a subset of the adjusted target levels. Fuzzy logic control rules can be used to calculate adjusted target levels not actually stored in the reduced boost table.

Abstract: A technique for eliminating the division in decoding a predicted DC coefficient includes calculating and storing the values of 1//DC_scalar in a table. This allows one to convert a division into a multiplication.

Abstract: We describe and claim an adaptive color burst phase correction system and method. The adaptive color burst phase correction system includes a signal detector to extract a color burst from a video signal, the color burst including a phase and an amplitude, an adaptive phase corrector to adjust the color burst phase responsive to corruption in the color burst, a Y/C separator to separate luminance and chrominance data from the video signal, responsive to the adjusted color burst phase, and a panel to display the luminance and chrominance data. The adaptive phase corrector includes a corruption detector to detect corruption in a color burst, a selector to select a phase correction value responsive to the detected corruption, and a phase adjuster to adjust a color burst phase responsive to the phase correction value.

Abstract: The invention relates to a semiautomatic keystone correction system and method. The system includes an interface and a controller. A user selects a plurality of corners within an image projected on a projection surface using the interface and the controller predistorts the image responsive to the selected plurality of corners where the predistorted image exhibits no distortion when re projected on the projection surface. The user further aligns a center of the image with a center of the projection surface, also using the interface. The controller predistorts the image by scaling the image in vertical and horizontal directions using vertical and horizontal scalars, respectively.

Abstract: A digital signal processing based decoder is disclosed. The decoder asynchronously samples video signals. By doing so, the decoder can work in pseudo real-time and without analog interface components improving performance while reducing cost.

Abstract: A multi-link receiving mechanism (MRM) is disclosed comprising a plurality of receivers. Each receiver receives a separate data stream, and all receivers receive the same clock signal. The data streams may arrive at the MRM out of alignment relative to each other (i.e. may have inter-pair skew), and the clock signal need not be aligned with any of the data streams. In response to the clock signal and the data stream, each receiver delays the clock signal by a variable delay to derive a reference signal. This is done to achieve a desired relative alignment between the data stream and the reference signal. Once the reference signal is derived, it is used by the receiver to generate a plurality of latching control signals. These latching control signals are thereafter used by the receiver to latch all of the data units of the data stream. Data from the data stream is thus recovered. Each of the receivers operates in the manner described to recover data from each of the data streams.