Abstract: A switcher mixer architecture creates special effects such as a dissolve or a wipe from one priority structure of the elements of an image scene to a completely different prioritized ordering of those same or even other elements that comprise the same or a different image scene. The special effect can be thought of as a "priority transition" in the sense that the priority of a set of input image signals can be transitioned from that of a "from" image to that of a "to" image. The switcher mixer architecture eliminates a soft border artifact from the special effect by allowing a border to be given its own priority as though the border were a separate image input as well as to couple together (1) a source, or "from," image having one or more elements; (2) a destination, or "to," image having one or more elements, which could be the same or different than the "from" image elements; and (3) a border image for separating the source image and the destination image in an image display.

Abstract: A keyed, true-transparency combine and keyer receive a plurality of image information signals V.sub.i, each having a corresponding input key signal Bk.sub.i, over a respective channel. The image signals are dynamically ranked in a prioritized order, even on a field-by-field basis. However, rather than switch the individual image signals as the prioritized order changes, the order of the channels is dynamically and switchably interchanged within a keyer by switchably interchanging a plurality of substantially identical keyer units while generating a plurality of processed true transparency image key signals Pk.sub.i. While there may be some structural distinctions among the keyer units, there is commonalty of function among the keyer units within the keyer. The keyer also generates processed background key signals Pk.sub.B. The keyer units are switchably changed to produce true transparency processed key signals such that processed key signal Pk.sub.

Abstract: A video effects system having a video channel with a recirculating loop for incoming video including means for processing or cutting the video signal during each recirculation, and separately processing video information from the recirculation loop to a combiner at the data output, so that the data output video may be different from the recirculated video.

Abstract: A video special effects mixer including an improved recirculating frame store is disclosed. The mixer receives several inputs one of which is from the recirculating frame store and provides several outputs one of which goes to the recirculating frame store. The recirculating frame store includes two field recirculation loops and an interpolator. The real field is mixed with the previous interpolated recirculated field and the interpolated field is mixed with the previous real recirculated field. The output alternates between the two mixed fields. The recirculating frame store receives a key signal indicating relative gain, and has a key processor that reduces the gain of the recirculating key such that the combined gain is no more than unity.

Abstract: A range of digital values is assigned to represent a digitized composite signal, while a selected digital value of the range is assigned as a unique dropout sample to represent only a dropout in the signal to the exclusion of signal data. In the event of a dropout, the unique dropout sample is loaded into memory in place of the corresponding incorrect signal data. The unique dropout sample is detected upon read out of data from memory and used to initiate the process of dropout compensation.

Abstract: An all-pass filter provides inversion of a chrominance component in a composite signal without separating the chrominance component from the composite signal, to provide for example, synthesizing composite video from a previous line of video. The filter includes an input for receiving the composite signal along a subsequent signal path, and the application of selected, preferably symmetrical weighting factors to selected locations along the signal path. The path includes selected delay means coupled to define a filter output via summing means. The latter provides the composite signal with inverted chrominance without an objectionable change in the relative phase and amplitude of the luminance components relative to the inverted chrominance.