Abstract: Disclosed is a method and apparatus for combining first and second video signals to produce a composite video signal for display. First and second video sources generate first and second video signals. A chroma key circuit is included for comparing each pixel of the first video signal with a preselected color and generating logic signals indicating whether or not each pixel matches the preselected color. An input lock map stores each of the logic signals when field data is in a first state and provides the logic signals on an output line thereof when the field data is in a second state. A frame buffer selectively receives (1) a complement of the logic signals when the field data is in the first state and (2) the logic signals when the field data is in the second state.

Abstract: An adapter for use in a multi-media workstation includes a device which accepts real-time video information at a first size, reduces the size to a selected one of a plurality of available sizes and places the reduced real-time video information into a selected area of the video memory of a computer graphic display device. Thereafter, the scaled real-time video information is displayed with other computer graphics applications, in a sub-window of the screen of the display device.

Abstract: This invention provides a method of and apparatus for compressing digital video color signals derived from a natural image and generating display signals for a color image composed of pixels derived from the compressed signals in which digital color signals representative of color depth intensities of three colors for each pixel to be displayed, each color signal having at least four bits representing the color intensity of a corresponding color for a corresponding pixel and arranged from most to least significant bits, are received; a digital dither signal for each pixel to be displayed is generated; a selected number of the most significant bits of each received color signal are summed with the corresponding generated dither signal; a selected number of the least significant bits of the summed color and dither signals are discarded to compress the corresponding received color signal; the compressed color signals related to a common pixel are concatenated to generate a digital output signal having a predeter

Abstract: A digital display system includes a monitor arranged to receive digital display data and synchronizing signals to develop displays on a cathode ray tube. The monitor is switched between different line structure and/or color definition modes in response to the polarity of one of the vertical or horizontal synchronizing signals trains. A circuit receives this train to provide control signals to the horizontal time base and/or a color signal code converter. The time base control signal, in accordance with its binary value, controls the frequency of the time base. The color converter, in response to the control signals, either passes color signals received in parallel over six input lines without change to the cathode ray tube drive circuits or converts color signals on four of the input lines to output signals on the six lines to the drive circuits.

Abstract: Dimensional variations, such as skew, alignment and abutment, in an array scanner are corrected by scanning and storing into a storage means an uncorrected electronic image generated from a test pattern. Correctional factors are generated from the stored electronic image. The correctional factors are used to correct the dimensional variations in the electronic image of the test pattern and/or dimensional variations in subsequent electronic image outputted from the scanner.

Abstract: A digital display system includes a monitor arranged to receive digital display data and synchronizing signals to develop displays on a cathode ray tube. The monitor is switched between different line structure and/or color definition modes in response to the polarity of one of the vertical or horizontal synchronizing signals trains. A circuit receives this train to provide control signals to the horizontal time base and/or a color signal code converter. The time base control signal, in accordance with its binary value, controls the frequency of the time base. The color converter, in response to the control signals, either passes color signals received in parallel over six input lines without change to the cathode ray tube drive circuits or converts color signals on four of the input lines to output signals on the six lines to the drive circuits.