Abstract: A video effects system comprises a graphics generator for generating a three-dimensional image in simulated real time, a digital video effects device for generating a second image and transforming the second image in real time, and a depth combiner for combining the three-dimensional image with the transformed second image to produce an output image that is the intersection of the three-dimensional image and the transformed second image.

Abstract: Data is embedded in a video signal by adding a low level wavefrom to the video signal, the low level wave form having a level below the noise level of the video signal and corresponding to the data. To detect the data embedded in the video signal the video signal is correlated with the low level waveform corresponding to the data to produce a correlation coefficient. A high correlation coefficient indicates the presence of a low level waveform which is converted into the data. The low level waveform extends over many video lines such that it does not occur at or near the same location within a video frame for many video frames to avoid fixed-pattern noise anomalies that may be detected by a viewer of the television picture.

Abstract: A video graphics memory storage reduction technique combines a frame buffer memory system with a run length encoded memory system by providing a luminance/chrominance decoder/multiplexer to convert output digital data segments from a memory into color components in lieu of using a color look up table. The digital data segments also are input to a detector and a switch, with the luminance portion being compared with a predetermined fixed value outside the valid luminance value range and the chrominance portion being passed through the switch in lieu of a constant when the luminance matches the detector value. A run length encoder logic circuit uses the output of the switch to generate access commands for the memory, and the detector causes the luminance/chrominance decoder to hold the last color until the next digital data segment is accessed by the logic circuit.

Abstract: A digital video generator provides for smooth scrolling of a video image across a video display device. A digital memory contains data to be displayed. Under control of a computer this data is transferred to a display memory as needed. The data is displayed with a gray scale intensity level for each pixel. Two successive pixels in the direction of movement are read out of the display memory, a current pixel and a next pixel, and are added together in a mixer with a weighting factor determined by the computer according to the scrolling speed selected to provide a weighted pixel. The weighted pixel is converted into analog video data or display. At intervals depending upon the selected scrolling speed the computer reloads the display memory from the digital memory to replace the data which has been displayed and scrolled off the monitor. Initial values for the top of the display field and the weighting factor are computed each display cycle.