Other

Faroudja Laboratories, Inc.

Genesis Microchip Corporation

Sage, Inc.

Yves C. Faroudja

Jack J Campbell

Yves C Faroudja

Thomas C Lyon

Xu Dong

Donald S Butler

Peter D Swartz

An interlaced television signal is derived from an interlaced 625 line, nominally 50 Hz field rate television signal, the derived television signal having perceived reduced line structure and reduce flicker. The field rate and the number of lines of the derived television signal are increased with respect to the field rate and the number of lines of the original television signal, such that perceived flicker and line structure in the derived television signal is reduced. The increase in the field rate and the increase in the number of lines in the derived television signal results in a horizontal scanning rate that does not substantially exceed twice the horizontal scanning rate of the original television signal while minimizing undesirable motion artifacts.

Reduced television display flicker and perceived line structure with low horizontal scan rates

An interlaced television signal is derived from an interlaced 625 line, nominally 50 Hz field rate television signal, the derived television signal having perceived reduced line structure and reduced flicker. The field rate and the number of lines of the derived television signal are increased with respect to the field rate and the number of lines of the original television signal, such that perceived flicker and line structure in the derived television signal is reduced. The increase in the field rate and the increase in the number of lines in the derived television signal results in a horizontal scanning rate that does not substantially exceed twice the horizontal scanning rate of the original television signal while minimizing undesirable motion artifacts.

A method or device for increasing the resolution of an image generates additional pixels in the image using interpolation. Various tests are performed for each additional pixel to determine whether conditions render the interpolation direction ambiguous or uncertain. In a television image, for example, an interpolation direction is derived for each additional pixel from a weighted combination of a vertical direction and a best-choice diagonal direction. If a potential interpolation condition cannot be determined with a high level of confidence, the weighted combination favors the vertical direction.

Adaptive diagonal interpolation for image resolution enhancement

Video sources from a progressively scanned camera are processed so as to simulate a video source derived from motion picture film. The simulated film source video creates a distinctive 'pseudo-film pattern,' in which at least some of every SDTV video field has no motion or low motion with respect to corresponding picture areas of the SDTV video field paired with it (occasional rare camera-originated scenes result in a field in which the entire picture has high motion, breaking the pseudo-film pattern). Corresponding picture areas within the pairs of fields having no motion or low motion are merged, in the manner in which interlaced fields derived from the same motion picture frame are merged. Corresponding picture areas within the pairs of fields having high motion are subject to interlace-to-progressive scan conversion processing which is not purely a merger of fields. The result, during a pseudo-film pattern, is a progressively-scanned picture tantamount to that produced by the progressively-scanned camera--no motion and low motion portions of the reproduced picture are very sharp and essentially identical to that of the original camera source, whereas high motion portions of the picture will have lower resolution, appearing slightly 'fuzzy.' The resulting psychovisual impression is essentially identical to that of an HDTV system which stays progressive all the way from the source to the display, but at a fraction of the complexity and cost.

High-definition television signal processing for transmitting and

An adaptive vertical low pass filter for a television signal process comprises an input for receiving an unfiltered video data stream and an output for putting out an adaptively low pass filtered video data stream. An adaptive processing circuit between the input and the output provides the adaptively low pass filtered video data stream in accordance with an adaptive control signal. A vertical condition detection circuit is responsive to at least one predetermined vertical condition at the input and includes a filtering component generator for generating the adaptive control signal in response to detection of the predetermined vertical pixel condition and for applying the adaptive control signal to the combiner circuit. The predetermined vertical pixel conditions may include vertical high frequency energy, integrated vertical high frequency energy, vertical impulses of one or two scan line durations irrespective of magnitude or direction, vertical transition edge levels, picture level or picture motion irrespective of magnitude or direction.

Adaptive vertical gray scale filter for television scan converter

A television scan conversion method receives and stores incoming pixel bits are stored in a pixel memory array at a first scan rate. Vertical columns of adjacent pixel bits of plural scan lines from the pixel memory array are read out at a second scan rate. A filter coefficient is generated by detecting a bit pattern located in each vertical column of pixel bits retrieved from the pixel memory array. Delay matched predetermined adjacent groups of pixel bits in each vertical column are adaptively low pass filtered in response to the filter coefficient so as to minimize video flicker artifacts in a resultant stream of interpolation pixels in accordance with the bit patterns detected by the pattern recognition filter coefficient generator. An interpolation coefficient is generated for each interpolation pixel, and plural-bit interpolation pixels are put out as a stream at the second scan rate.

Scan converter with adaptive vertical filter for single bit computer

A video pixel interpolator generates interpolation pixels from incoming picture image pixels for use within a television picture scan line doubler system. The interpolator includes a temporal median filter for generating an interpolation pixel by selection of the median one of a plurality of temporal pixel samples derived from incoming video, an intra-field averager means for generating an intra-field pixel average, and a switch connected to switch an input to a line doubler of the system between outputs of the temporal median filter and the intra-field averager in response to detection of pixel motion within the picture image. Improved motion detection, and multi-channel processing are also included within the present invention.

Television scan line doubler including temporal median filter

A motion sequence pattern detector detects a periodic pattern of motion sequences within a succession of video fields, such as film mode or progressive scan mode and comprises a motion detector for detecting the presence of motion from increment to increment within predetermined increments of the succession of video fields and for thereupon putting out a first motion detection signal for each said increment, and logic circuitry responsive to the first motion detection signal for detecting the periodic pattern of motion sequences within the succession of video fields.

Motion sequence pattern detector for video

A television line doubler having a video pixel interpolator and a multi-component motion detector including at least one frame-recursive component for detecting a motion value in the area of the pixel to be interpolated. A second switch switches its output to an interpolated pixel time compression circuit in accordance with the detected motion value. The second switch and the motion detector provide a proportional switch with an onset at approximately 2 to 5 IRE units of motion value and operating in accordance with the absolute amplitude of the motion value. Full switchover to the intra-field interpolator means occurring at approximately 5 to 15 IRE units of motion value amplitude. The motion detector stretches the detected motion to a predetermined number of adjacent pixel location in the line domain and a recirculation loop enables a component of motion to be recirculated.

Improved separation of audio and video spectra carried upon spectrally separated audio and video carriers within a television transmission channel leading to a television receiver is realized in a method which includes the transmission steps of: obtaining a high frequency luminance component at the vicinity of the audio carrier offset from the video carrier from a full bandwidth baseband luminance signal received from a video source; limiting the amplitude of luminance energy groups within the high frequency component to be below a predetermined amplitude level; combining the amplitude limited high frequency component into the full bandwidth luminance signal in a manner which provides a composite luminance signal having amplitude limited high frequency energy groups at the vicinity of the audio carrier; adding video synchronizing information to the composite luminance signal to provide a signal video modulation signal; modulating said video carrier with said single video modulation signal; combining the video carrier with the audio carrier into a resultant television composite; and, passing the resultant television composite through the television transmission channel to the television receiver. The method further includes making the audio carrier phase coherent with picture synchronizing information thereby enabling interleave of high frequency video and audio energies. Comb filter separation of video from audio energy groups may then be employed at the receiver.

Television transmission system having improved separation of audio and

A method for reducing ringing artifacts caused by low pass filtering of baseband television signals comprises the steps of: detecting the occurrence of a horizontal transition in the baseband television signal as by measuring its magnitude and spectral slope, developing a control signal from the detected horizontal transition which is related in duration to the horizontal transition, applying the control signal smoothly and adaptively to modify the structure of a low pass filter structure during the duration of the control signal to minimize ringing response of the structure.

Adaptive ringing reducer for television signal processing

A method is disclosed for reducing bandwidth of a chrominance path to reduce cross-color artifacts in a quadrature modulated color television signal. The method includes the steps of detecting the level of a chrominance component of the signal; developing a control signal from the detected chrominance component level; and, controlling the bandwidth of the chrominance path in accordance with the control signal so as to reduce bandwidth only when chrominance component is at a level below a predetermined threshold. The method for developing a control signal may further include the step of eliminating the sign thereof followed by a step for establishing a predetermined minimum threshold value of the absolute value chrominance level below which the control signal is not generated.

Bandwidth control for chrominance and luminance paths in quadrature

An improved comb filter extracts at least one of chroma and luminance from a quadrature modulated subcarrier color television input signal. The described method implemented by the described apparatus includes the steps of delaying the input signal through a plurality of predetermined delay periods wherein the duration of each delay period is related to line scan period or picture frame period, filtering the undelayed and delayed signals so that energy components of the input signal lying in the vicinity of the chroma subcarrier frequency are passed, thereby providing bandpass filtered undelayed and delayed signals, detecting amplitude and sense of periodic transitions lying in the chroma energy passband, multiplying two of the undelayed and delayed signals by the continuously variable coefficients to produce an error correction signal corresponding substantially to the following approximation:

Comb filter method and apparatus for chrominance and luminance

In a television system a transition level signal booster decreases transition time of low level transitions within a video signal without creating artifacts incident to high level transitions within the video signal. The booster includes an input for receiving the video signal, an output for putting out a main path video signal in which transition times of low level transitions have been decreased, a main path for the video signal extending between the input and the output, the main path including a main path adder means for adding a transition boost signal to the video signal, a transition boost signal generator including a connection to said input for receiving the video and for generating the transition boost signal, the generator comprising: a high frequency transition signal generator for generatigng a high frequency transition signal incident to the detection of a transition level in the video signal, a wave shaper including a first path having a delay match in series therein for putting out a first signal and a second path in parallel with the first path, the second path including sign removal and shaper means therein for generating a second control signal having a decreasing amplitude for each video transition having a magnitude above a predetermined amount, a first multiplier for multiplying the first signal by the second signal to generate the transition boost signal, said multiplier being connected to said main path adder means so that said transition boost signal may be added to the main path video signal, thereby to decrease the transition times of low transition levels.

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San Francisco, CA, United States of America

Jack J Campbell