Abstract: A method and apparatus is disclosed which minimizes the visual artifacts normally generated when images are compressed for transfer through very narrow band channels such as, for example, the Internet. To this end, the images are pre-filtered and then scaled down prior to compression using a two dimensional spatial impulse filter with good pulse fidelity rather than flat pass bands, rapid cutoff at high frequency and minimal impulse response width. The impulse filter preferably is operated at the 6 db point down about 0.6 to 0.9 of the output image spatial band edge, thereby removing visible aliases in the images while compromising between subjective sharpness and total picture entropy.

Abstract: A digital servo track pattern for a magnetic medium which can be recorded and reproduced by a recording and reproducing system. The servo track pattern has a plurality of digital mark patterns recorded thereon, each of said digital mark patterns having a leading identifier field of digital bits, a trailing identifier field of digital bits and a field of digital synchronizing data located between said leading and trailing identifier fields. The leading identifier field of digital bits is electrically equivalent during reproducing while the medium is moving in a first direction to the trailing identifier field of digital bits while the medium is moving in a direction opposite to said first direction.

Abstract: A magnetic transducer for reproducing/recording high frequency signals with a magnetic tape medium includes a pair of opposed transducer head halves separated by an insulation gap and bonded together to form a Y-shaped pole structure, each half including a laminated at least partially ferromagnetic core portion bounded on opposite surfaces with outer and inner conductive layers, each of which forms a winding coil portion. Each core section has a leg portion and an angularly disposed arm portion, the distal end of which is capped with a block-shaped ferromagnetic pole tip in magnetic path relation therewith, the two pole tips lying in a common plane transverse to the plane of the gap. The conductive layers, when conductively interconnected, such as by jumpers, form a one or two turn coil for the transducer.

Abstract: An audio receiver FIFO memory buffer in the serial digital video interface allows improved timing synchronization between video and audio information. Furthermore, it eliminates unpleasant sound effects when multiple data samples are skipped or repeated in series. This FIFO receiver buffer receives data at an input write-data rate filling up the memory storage cells therein. An output read-data signal clocks the data out of the memory storage cells. The FIFO's fullness is monitored and maintained, in response to an external signal, to within a specified range delimited by an upper and a lower threshold. If the FIFO buffer fullness is below the range's lower threshold, then the FIFO's read address pointer is held so that the immediately preceding read out data element is read out again, but only once. On the other hand, the FIFO buffer fullness is over the range's upper limit, then the FIFO's write address pointer is held so that the immediately preceding written in data element is written over, but only once.

Abstract: Deteriorated or aged magnetic recording media exhibiting undesirable properties such as shed, stickiness or squeal are restored to playable condition having no such objectionable properties by heating the media to an elevated temperature and for lengths of time sufficient to restore the media. A typical temperature used is 54.degree. C. and a typical effective time is 16 hours. Ambient humidity is suitable. The restored media can be used to transfer data or information to new media. Restored media can also be again heat treated for restoration purposes, if it deteriorates again.

Abstract: A magnetic transducer has a transducing gap that is wider than that used for transferring information signals with respect to a magnetic record medium. A magnetic control flux is applied to the transducer to enable a selected segment of the transducing gap, which defines a transducing zone, for transferring information signals with respect to a selected path along the magnetic record medium. Registration of the transducing zone over the selected path is maintained by varying the applied magnetic control flux to thereby move the transducing zone along the wider transducing gap so as to compensate for deviations between the path traced by the transducing zone over the magnetic record medium and the selected path.

Abstract: Disclosed are magnetic particle coating compositions employing a low molecular, high T.sub.g vinyl polymers characterized by having one or more primary alcohol containing groups pendant to the polymer chain.

Abstract: Apparatus is described for coupling magnetic flux defining information between a first body of magnetic material and a second body of magnetic material having a magnetic flux path therein. A third body of magnetic material having a transducing zone is included and disposed to be magnetically proximate the first body of magnetic material to couple flux to or from the same, and to have a portion thereof magnetically proximate the magnetic flux path within the second body of magnetic material to provided coupling of flux to or from such flux path. In specific embodiments described, the first body of magnetic material is a magnetic storage medium such as a layer of hard magnetic material of a tape, and the second body of material is a transducer core of a soft magnetic material.

Abstract: A magnetic transducer arrangement includes a core with a gap and a body of magnetically anisotropic material in which a signal transfer region is defined. Control flux flows across the gap of the core and through the body in opposite directions. The two oppositely directed flux flows influence one another and tend to cancel each other to define a null zone. This null zone, in which the flow of control flux is very low, is sensitive to flux emanating from an adjacent magnetic storage medium and therefore defines the signal transfer region. By varying the relative proportions of control flux flowing in the opposite directions, the location of the null zone can be varied along the width of the magnetic transducer to thereby scan the signal transfer region. The flux which is coupled from the magnetic storage medium into the null zone of the body does not flow through the magnetic core in a manner similar to a fringing flux.

Abstract: Magnetic record media are described that have an overlying or underlying magnetically saturable high permeability keeper layer in addition to a high coervicity magnetic layer in which magnetic signals are stored. These media are used in magnetic signal processing devices whose transducers are capable of generating a keeper layer-saturating bias flux. In signal reproduction the bias flux magnetically forms a saturation zone in the nature of virtual gap in the keeper layer that directs signal flux between the media and the transducer.

Abstract: Apparatus and methods for encoding information of one class into the parity for main data of another class. One such method and apparatus fundamentally takes one member A.sub.x of a limited first class of data called attribute data and concatenates it with main data. Parity is then calculated on the concatenate word. After the main data and parity is transmitted or recorded, the selected member of the first class of data may be recovered by comparing the received parity to the parity P" generated on the receiver side using the main data and each member of the first class of data to generate a plurality of syndromes. The first all zero syndrome identifies the member of the first class which was encoded into the parity of the main data. Another method and apparatus are similar except that the transmitter side calculates parity P.sub.ax for the selected member of the first class and then encodes that parity into the parity calculated for the main data.

Abstract: Magnetic transducer-keeper combination embodiments of the invention are described. Each has a magnetic core defining a physical gap and a thin magnetic keeper arranged in close proximity of the core to bridge the gap. A magnetic flux from the gap saturates the keeper inan area bridging the gap, thereby forming a signal transducing zone in the keeper. The keeper is maintained stationary and the core moved or scanned with respect to the same, thereby moving or scanning the transducing zone in the keeper.

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: The gain of an input video signal of different possible gains relative to a selected reference gain is adjusted according to an associated key signal indicative of gain change previously undergone by the input video signal and an independent key signal indicative of the desired change in gain to produce an output video signal having a selected gain determined by the values of the associated and independent key signals. The output video signal is combined with other video signals, whose gain may or may not have been adjusted relative to the reference gain.

Abstract: A method and apparatus for producing special motion effects such as slow or fast motion, still frame and other effects from video magnetic tape is disclosed which is particularly applicable to helical wrap recording and reproducing apparatus. The apparatus employs a transducing head that is mounted on a revolving scanning drum, with the head being movable in a line generally transverse to the recorded track. The present invention utilizes the transverse positioning of the head to accurately follow a track during reproducing or playback and, at the completion of the track, to properly position or set the head in position to either play the next adjacent successive track, replay the same track, or play yet another track so that special motion effects can be achieved without experiencing picture breakup or unwanted noise.

Abstract: A system for spatially transforming images by separate transformation of each dimension of the image is exemplified by a raster scan television system which includes for each color component a transposing memory providing a change of scan direction from horizontal to vertical, a vertical transformation system transforming in the vertical direction the vertically scanned video information, a second transposing memory coupled to receive vertically transformed video information and provide a change of scan direction from vertical back to horizontal, and a horizontal transformation system coupled to horizontally transform the horizontally scanned video signal to produce a color component output signal.

Abstract: A TV video signal synchronization signal system enables a video device such as a digital special effects system to operate synchronously in response to an input video signal and still produce an output video signal synchronized to a television studio locking reference signal. The video device and the synchronization signal generating subsystem thereof operate in response to a pixel rate clock of approximately 70 ns and in response to a phase command to generate timing for the horizontal sync pulse, color burst signal and video data of the output video signal. The output color burst signal remains phase locked to the locking reference signal with output gating being responsive to the phase command. A ROM interpolator provides subpixel accuracy for the output horizontal sync pulse while output line buffering and interpolation permits the output video data to be phase matched to the reference master sync signal.

Abstract: There is disclosed herein a system for digitally forming synchronization signals. In the preferred embodiment, these synchronization signals are for substitution in place of the original synchronization signals in a television signal. These digitally generated synchronization signals are generated synchronously with the digitization of the video portions of the television signal, and the digitally generated synchronization signals are multiplexed into the stream of digital video data in the appropriate blanking intervals. The system uses a first digital signal number generator to generate a plurality of digital signals which represent the peak amplitudes of the desired synchronization signals. A second digital signal number generator synchronously generates a second plurality of digital signal values representative of the shape of the desired edges for the synchronization signal being generated.

Abstract: Errors in data words recovered following the transmission of digital data having internal correlation are concealed by substituting recovered correlated words for recovered words suspected of being in error. Concealment may follow the correction of errors according to an error correcting code. Error flag signals are used to identify corresponding respective recovered words that are suspected of being in error. These error flag signals are counted over a predetermined totaling interval, and a concealment interval signal is generated for a concealment interval when the count exceeds a predetermined threshold count. Recovered correlated words are substituted for recovered words corresponding to respective error flags and for all other recovered words corresponding to a respective concealment interval. In accordance with one aspect of the invention, the concealment interval is centered upon the corresponding totaling interval.

Abstract: A method and apparatus is disclosed for controlling the sampling of a composite analog color video signal so that the analog signal is sampled at precise locations relative to the phase of the color subcarrier of the color video signal in the absence of modulation. The invention thereby enables a digitized signal having a constant phase relationship relative to the unmodulated subcarrier phase to be provided which can be advantageously used in magnetic recording and reproducing apparatus. Since the constancy of the location of the samples relative to the phase of the color burst is maintained prior to recording, there is no phase error that would pose a problem during reproducing of the signal.