Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/015—High-definition television systems
  • H04N7/0152—High-definition television systems using spatial or temporal subsampling
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N11/00—Colour television systems
  • H04N11/06—Transmission systems characterised by the manner in which the individual colour picture signal components are combined
  • H04N11/08—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using sequential signals only
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N11/00—Colour television systems
  • H04N11/24—High-definition television systems
  • H04N11/28—High-definition television systems involving bandwidth reduction, e.g. subsampling
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
  • H04N19/186—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a colour or a chrominance component
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
  • H04N19/59—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution

Definitions

• the invention relates to the field of television signal transmis ⁇ sion systems and, in particular, to a television signal transmission system for transmitting a signal providing a higher resolution image than is transmitted under standard resolution National Television Sub ⁇ committee (NTSC) or European formats.
• NTSC National Television Sub ⁇ committee
• Another solution to the problem of transmitting a high resolu ⁇ tion image is to transmit a standard television signal and to create and transmit a so-called augmentation channel.
• a new receiver is required for pro ⁇ cessing the received signal of standard bandwidth.
• no change in receiver circuitry is required for receiving and displaying a standard resolution image.
• sepa ⁇ rate adapter circuitry is required for receiving the augmentation channel containing high resolution data and for reinstituting the high resolution data into the standard resolution image to provide a high resolution image.
• the present invention relates to a method and apparatus for transmitting and receiving a high definition multiplexed analog com ⁇ ponents (MAC) television signal.
• MAC multiplexed analog com ⁇ ponents
• the video signal is carried within an active line period while all other signals comprising at least audio, control data, utility data and teletext are transmitted during a line blanking period or a longer field blanking period.
• Sepa ⁇ rate luminance and chrominance signals are digitally sampled, com ⁇ pressed and transmitted during separate portions of a video line sig ⁇ nal.
• luminance samples are compressed for transmission at a ratio of 3:2 while chrominance is compressed at a ratio of 3:1.
• Chrominance informa ⁇ tion is translated into U and V components, each component being transmitted every other line.
• a folding of high horizontal resolution information is accomplished into the high frequency diagonal components of the sampled video signal.
• baseband frequencies below 5 MHz (7 MHz when time- compressed 3:2 according to the format) the spectrum is unmodified.
• standard B-MAC decoders are typically equipped with 6.3 MHz passband lowpass filters at their input, the folded high resolution information does not affect reception. The additional transmitted information at high frequencies is simply blocked and ignored.
• a high definition analog television signal is first orthogonally sampled at 28 MHz (a rate of eight times the color subcarrier of 3.58 MHz or 8 Fsc).
• 28 MHz a rate of eight times the color subcarrier of 3.58 MHz or 8 Fsc.
• a two dimensional sample spectrum is achieved which is then passed through a diagonal digital filter which decreases the diagonal frequency response but which decrease is practically imperceptible to a viewer.
• the diagonally filtered data is then decimated by_discarding alternate samples on alternate lines.
• a figure-of-five or quincunx pattern of samples remains.
• the baseband spectrum remains unchanged but high resolution repeat spectrums comprising horizontal and vertical resolution components exist at half the sampling frequency and at the sampling frequency.
• the repeat spectrums serve to fold additional resolution into the baseband signal.
• the samples of the folded signal may then be converted to ana ⁇ log form and passed through a low pass skew-symmetric filter cen ⁇ tered at seven megahertz or similarly digitally filtered. Accordingly, high resolution information related to the horizontal dimension is folded about a diagonal axis at seven megahertz into the approxi ⁇ mately five to seven megahertz or high frequency portion of the passed baseband signal. Effectively, the high resolution information is traded for the diagonal information.
• the digital diagonal filter of the encoder may comprise separable hori ⁇ zontal and vertical filters.
• the vertical filter at the transmitter may be very simple provided the horizontal filter is sufficiently complex to achieve a 40db rejection in the stop band.
• the hori ⁇ zontal filter at the transmitter (permitting a 0-5 MHz passband) may be at a complexity on the level of sixteen coefficients.
• a much less expensive and simpler diagonal filtering arrangement may be employed at the receiver.
• a 5-MHz low-pass filter at the receiver need comprise only eight coefficients. While the invention is described in terms of improving luminance horizontal detail, the technique and apparatus may be adapted for improving chrominance horizontal detail.
• An embodiment for improving chrominance horizontal detail applies similar principles to those applied for improving luminance horizontal detail. However, an intentional increase in horizontal chrominance detail has been found to be unnecessary for a B-MAC signal, allowing a simpler technique for chrominance transmission.
• a vertical filter interpolator receives at its input a 525 line, 1:1 non-interlaced signal, a 1050 line, 2:1 interlaced signal or an 1125 line 2:1 interlaced signal.
• the signal is appropriately filtered in a vertical direction and an output provided to a 4:1 line decimation cir ⁇ cuit.
• the output of the line decimation circuit is filtered in a hori ⁇ zontal dimension about a center frequency of 2.5 megahertz and the high frequency output samples provided to a multiplexer.
• the multi ⁇ plexer combines the chrominance, luminance and any data/audio sig ⁇ nals for transmission.
• the combined high definition B-MAC signal may be passed through a skew-symmet ⁇ ric filter portion centered at 10.7 megahertz which in combination with a complimentary filter portion at a decoder eliminates aliasing in a decoded signal. Consequently, the same skew-symmetric filter portion of the encoder may be shared for both luminance and chrominance processing.
• Figure 1 is a graphical depiction of vertical versus horizontal definition for a high definition television signal.
• Figure 2 is a representation of an orthogonal sampling grid for sampling the signal of Figure 1 at 28.6 megahertz (8 Fsc after prefiltering at 9.0 megahertz).
• Figure 3 is graphical depiction of vertical versus horizontal definition as a result of application of the orthogonal sampling grid of Figure 2 such that a baseband spectrum results as well as a repeat spectrum centered at the sampling frequency.
• Figure 4 is a graphical depiction of vertical versus horizontal definition with diagonal information, a block of data, for example, between five and nine megahertz, having been filtered from the orthogonally sampled spectrums of Figure 3.
• Figure 5 is a representation of a sampling grid at 14 MHz gen ⁇ erated by discarding alternate samples on alternate lines to achieve a figure-of-five or quincunx sample pattern.
• Figure 6 is a graphical depiction of the result of the decimation of alternate samples where, besides the repeat spectrum at 28 MHz, two repeat spectrums at 14 MHz, half the initial sampling rate are introduced.
• Figure 7a is a graphical depiction of vertical versus horizontal resolution for showing the process of filtering about a center fre ⁇ quency of approximately 7 MHz, the filter having a skew-symmetric low-pass response and Figure 7b the characteristic amplitude versus frequency response.
• Figure 8 is a graphical depiction of a first step of processes accomplished at a receiver.
• Figure 8a represents a first graphical depiction of vertical versus horizontal definition
• Figure 8b represents a second graphical depiction of amplitude versus frequency showing how aliasing is eliminated and information close to 7 MHz is regenerated by the skew-symmetric characteristic of the filter.
• Figure 9 is a graphical depiction of vertical versus horizontal definition showing the result of upconverting rom 14 megahertz to 28 megahertz.
• a null for high diagonal frequen ⁇ cies in the range of 5-9 megahertz is produced leaving a signal having high horizontal resolution but an imperceptible sacrifice in diagonal information.
• Figure 10 is a schematic diagram of apparatus of a transmitter for encoding a high definition B-MAC television signal.
• Figure 11 is a schematic diagram of apparatus of a receiver for decoding a high definition B-MAC television signal.
• Figure 12 is a graphical representation of the characteristic response of the sixteen coefficient horizontal low-pass filter, includ ⁇ ing coefficient data, shown in Figure 10.
• Figure 13 is a graphical representation of the characteristic response of the eight coefficient horizontal low-pass filter, including coefficient data, shown in Figure 11.
• Figure 14 is a graphical representation of vertical resolution in lines per picture height versus horizontal resolution in lines per pic ⁇ ture width showing characteristics of the application of the present invention in combination with conventional but proprietary scan con ⁇ version line doubling techniques in B-MAC versus results of more expensive multiple field store techniques used in a 1125 line MUSE signal transmission system.
• Figure 15 is a graphical representation of amplitude versus frequency and horizontal versus vertical resolution for the three fil ⁇ ters applied in the present technique: diagonal filtering, - pref iltering and skew-symmetric filtering, Figure 15a being of amplitude versus frequency and Figure 15b being of vertical versus horizontal resolution.
• Figure 16 is a graphical depiction of the two dimensional con ⁇ tour response of the transmitted signal comparable to Figure 14, hori ⁇ zontal resolution being traded for diagonal resolution in a system according to the present invention.
• Figure 17 is a block schematic diagram of luminance processing circuits at the location of a high definition B-MAC encoder in accor ⁇ dance with the present invention.
• Figure 18 is a block schematic diagram of chrominance pro ⁇ cessing circuits at the location of a high definition B-MAC encoder in accordance with the present invention.
• Figure 19 is a block schematic diagram of processing at the location of a high definition B-MAC decoder in accordance with the present invention.
• Figure 20 is a block schematic diagram of a high definition television receiver for processing the output of the high definition B-MAC decoder of Figure 19.
• Figure 21 is a block schematic diagram of a high definition television receiver having multiple applications in a high definition or standard resolution television environment.
• FIG. 1 there is shown a high definition televi ⁇ sion signal graphically depicted in terms of vertical versus horizontal resolution.
• the present method is assumed applica ⁇ ble to a high definition 16:9 aspect-ratio picture scanned sequentially using 525 lines, the horizontal resolution being at least 945 lines at 9 megahertz.
• a sequential scan signal of this type supports a vertical definition of 480 lines.
• this description refers by way of example to a new type of B-MAC signal which carries increased reso ⁇ lution at the imperceptible expense of diagonal resolution.
• the increased resolution is folded into the high video frequencies.
• baseband frequencies below 5 MHz (7 MHz when time-compressed in MAC) the spectrum is unmodified.
• B-MAC decoders have low-pass input filters having a pass band limited at 6.3 MHz, decoder operation is unaf ⁇ fected by the additional transmitted information.
• a B-MAC decoder in accordance with the present invention retrieves and decodes the folded horizontal detail information and causes a high resolution image to be displayed by a receiver.
• a standard resolution 525-line 2:1 interlace video signal con ⁇ sists of two fields each containing 240 active lines. Lines of every other (odd) field are spatially offset relative to lines of even fields so that all 480 active lines are regularly spaced on the display screen.
• this line structure can carry a vertical resolution equal to 480 lines for static pictures.
• a normal interlaced display does not achieve this value.
• the reason for this lies in the fact that only 240 lines are displayed in each field, and the human eye/brain is expected to sum the two fields and perceive all 480 lines. It cannot do this perfectly.
• the intensity of the first field perceived by the eye/brain has decreased to 50% of its initial value by the time that the second field arrives (1/60 seconds later). This has two consequences:
• Kell Factor may be entirely eliminated and resolution restored to 480 lines by displaying all 480 lines (from both odd and even fields) in each 1/60 second field period.
• This technique is known as scan conversion.
• Application of the technique involves use of a field store memory storing all 240 active lines to move infor ⁇ mation between fields, and a display at twice the normal line fre ⁇ quency.
• the method can be directly applied only to static parts of the picture, since significant motion can occur between fields. Consequently, a motion detector is also required so that inter- field interpolation can be used for stationary objects, while line-interpolation is used for moving objects.
• Sean conversion tech ⁇ niques employing adaptive field-store line doubling techniques thus achieve 480 lines of vertical resolution for static pictures and approx ⁇ imately 320 lines in moving dynamic areas of an image.
• Field store line-doubling is gaining acceptance as a standard method for increasing vertical definition by TV-set manufacturers. Its main advantage is that it eliminates line structure and signifi ⁇ cantly improves picture quality without requiring any additional information transmitted.
• Several manufacturers of TV-sets and pro ⁇ jectors are using proprietary line-doubling techniques, including Philips, Hitachi, Sony, Ikegami, etc. Its obvious advantages are:
• the technique applies equally to component signals (luminance, chrominance) or NTSC signals received from any source including S-VHS VCRs.
• the technique is applied in the television receiver and therefore permits retention of a 525 interlace connec ⁇ tion to the TV-set (NTSC or wideband Y/C).
• the field-store in the TV set image projector can be used for other consumer features such as picture-in-pic- ture and noise reduction,
• the technique requires no additional transmitted infor ⁇ mation and allows any high definition television (HDTV) format to concentrate on the problem of increasing hor ⁇ izontal definition.
• HDTV high definition television
• the present high definition MAC system employs sub-Nyquist sampling (spectrum olding) to trade diagonal resolution for increased horizontal resolution.
• the process will be described in connection with Figures 2-9 and the apparatus at a transmitter or receiver will be described in connection with Figures 10-11. All frequencies quoted (bandwidths and sampling frequencies) will be referred to the uncompressed luminance signal of a B-MAC signal. Equivalent band- widths and sample frequencies in the time-compressed (MAC) domain must be increased by a actor of 1.5 (3:2).
• This signal is initially sampled at 28.6 MHz (8 Fsc) using an orthogonal sampling grid as shown in Figure 2.
• orthogonal sampling grid As a result of orthogo ⁇ nal sampling and in accordance with Figure 3, a baseband spectrum as well as a repeat spectrum centered at the sampling frequency results.
• the baseband spectrum comprises high horizontal resolution compo ⁇ nents at as high as 9 MHz or 945 lines as calculated above.
• a diagonal digital filter is then applied which decreases the diagonal frequency response (Step 2).
• Separable horizontal and verti ⁇ cal filters are employed for simplicity as will be further described in connection with the discussion of Figures 10 and 11. Referring to Figure 4, it may be seen that blocks of diagonal (horizontal versus vertical) information are removed at horizontal frequencies between five and nine megahertz in the baseband spectrum as well as the repeat spectrum.
• Step 3 is a sequence of digital samples which now have the compacted 2-dimensional spectrum shown in Figure 6 wherein repeat spectrums exist at the fourteen megahertz sampling frequency of the alternate sample decimation step.
• the horizontal resolution improvement information is folded into the signal for transmission.
• the samples may be converted to analog form and passed through a transmission filter with specific characteristics.
• the analog trans ⁇ mission filter may have skew-symmetric low-pass response which is -6dB at 7MHz.
• the result is shown in Figure 7a where high resolution information at 7-9 megahertz is translated to fill the void formed from diagonal filtering.
• a digital non-recursive filter may be applied as will be further described herein alleviating a requirement for digital to analog conversion or upconversion to 28 megahertz sampling.
• the signal When the signal is received, it is resampled at 14 MHz using the alternate line quincunx (figure-of-five) sampling pattern (step 6). By resampling at fourteen megahertz, a translation of the high frequency information occurs to 7-9 MHz according to Figure 8a.
• the resampling process thus regenerates the horizontal energy between 7 MHz and 9 MHz.
• the alias term introduced is necessarily cancelled no matter where the amplitude A is measured in the overlapping dashed line, solid line area proximate to 7 MHz.
• a diagonal filter (which produces a null for high vertical fre ⁇ quencies in the range of 5-9 MHz) cannot be implemented at the 14 MHz sample rate. Therefore, the up-conversion of sample rate to 28 MHz occurs as a part of the digital filtering process. According to Figure 9, the upconversion and diagonal filtering results in a null at diagonal frequencies and improved horizontal resolution.
• Step 7 results in a sequence of samples at 28 MHz with an orthogonal sampling grid. They carry a spectrum with horizontal res ⁇ olution of 9 MHz, with no aliasing. These samples are available for direct conversion to analog form. After bandlimiting to 9 MHz, the analog signal may be displayed on a high definition receiver.
• the samples may be passed directly to a known but proprietary field-store scan converter for line-doubling to increase the vertical definition such as the apparatus described by U.S. application Serial No. 255,238, entitled “Method and Apparatus for Improving Vertical Definition of a Television Signal by Scan Con ⁇ version" of Christopher Birch filed October 11, 1988 and incorporated herein by reference.
• the result of the scan conversion is a 525 sequential-scan signal sampled at 56 MHz (2 x 28 MHz) and carrying horizontal luminance resolution up to 18 MHz. (The line doubling pro ⁇ cess halves the active line period and doubles both the sampling fre ⁇ quency and the video bandwidth).
• the described process provides a very cost effective imple ⁇ mentation in a multiplexed analog component signal transmission sys ⁇ tems as will be described in connection with block schematic dia ⁇ grams Figures 10-11 of the encoder and the decoder respectively of the present apparatus.
• Transmitter apparatus performs all steps of the above described process but for transmission: step 1, 28 MHz orthogonal sampling after application of an 8.7 MHz pre-filter; step 2, digital diagonal filtering; step 3, 28 MHz - 14 MHz alternate sample decimation; and step 4, digital to analog conversion and skew-symmetric trans ⁇ mission filtering.
• Figure 10 shows a configu ⁇ ration in which the main elements of the digital filter can be imple ⁇ mented at a 14 MHz sample rate.
• the diagonal filter is implemented as two separable (horizontal and vertical) filters. It has been found that the vertical filter can be very simple i.e., a line store 101 and adder 102 provided the horizontal filter 103 achieves approximately a 40 dB rejection in the stop band. To accomplish such a rejection, the horizontal filter 103 (5 MHz low- pass) employs 16 coefficients at 28 MHz. The design of the horizontal filter 103 is a symmetrical non-recursive filter which has been opti ⁇ mized with 9-bit coefficient values. The response and the coeffi ⁇ cients are presented in Figure 12.
• switch 100 switches alternate samples of a pre-filtered 28 MHz sampling signal into two 14 MHz paths.
• the samples are vertically filtered and horizontally filtered.
• the lower path is substrated from the upper path at adder 102 while the upper path is added to the lower path at adder 104.
• a low pass combing characteristic with zero energy at zero frequency while at the output of adder 104 is shown a low frequency combing characteristic (solid line) with energy at zero frequency extending to 9 MHz and a high frequency aliased characteristic (dotted line) extending from 5 MHz up.
• the result at the output of adder 105 is a signal for transmission with horizontal resolution folded into the 5-7 MHz region. For each al, bl sample pair, one sample remains from quincunx sampling on alternate lines, separated by 14 MHz as shown. Consequently, a 28 megahertz process is accomplished at 14 MHz because of the alter ⁇ nate sample decimation.
• Figure 11 shows the decoder, in which it is also possible to implement the digital filter at 14 MHz.
• the 5 MHz low- pass filter ill contains only 8 coefficients, the characteristic response and coefficient data are shown in Figure 13.
• a 14 MHz input signal is sampled accord ⁇ ing to the figure-of-five sampling pattern shown at 14 MHz.
• the receiver decoder further comprises adder 112 and line store 113 in an upper path.
• the lower path further comprises interpolation circuit 114 including single element delay D and averager (divide-by-two) circuits for restoring missing data to the sample pattern.
• the upper and lower paths are switchably upconverted at 28 MHz and added at adder 115.
• Figure 14 shows the idealized two-dimensional frequency response achieved by the system in comparison with the known high definition 1125-line MUSE system developed by Japan Broadcasting Corp. (NHK).
• the MUSE system involves a plurality of field stores and thus is considerably more expensive to implement than the present invention including scan conversion apparatus involving one field store. Nevertheless, for dynamic or static images, the horizon ⁇ tal resolution is either equivalent or clearly superior to the MUSE system according to the present invention and with scan conversion is _almost comparable in vertical definition.
• Figure 15 shows the actual response achieved using the filters which have been described.
• Fig. 15a the position of the folded energy (hatched area) is also shown in one-dimension.
• A relates to the encoder diagonal filter, B to the pre-filter and C to the skew-symmetric filter.
• the skew-symmetric transmission filter may be implemented in analog form, according to the above-described method.
• a symmetrical non-recursive filter may be used alternately which produces an ideal linear phase characteristic. If a digital filter is used to create the skew-symmetric response, it is unnecessary to up-convert to 28 MHz sampling.
• Figure 16 shows the actual 2-dimensional response achieved by the system. From Figure 16 in comparison with Fig. 14 shows improved horizontal resolution out to 945 (950) lines at the cost of diagonal information.
• luminance horizontal resolution is improved and with scan conversion vertical resolution improved as well.
• the present invention may be adapted to provide improved chrominance horizontal resolution recognizing the 3:1 compression of U/V chrominance data in alternate transmitted lines. Scan conversion has -already been adapted for obtaining chrominance vertical resolution improvement.
• B-MAC to intentionally improve chrominance resolution may not be required.
• FIG. 17 there is shown a block diagram of cir ⁇ cuitry for luminance processing at an encoder location which works in concert with circuitry for chrominance processing at the same encoder location.
• the separate pro ⁇ cessing paths share the same skew-symmetric filter portion 1710.
• a 525 line 1:1 non-sequential scan, a 1050 line 2:1 interlaced or a 1125 line 2:1 interlaced video luminance signal is provided to a ver ⁇ tical filter/interpolator circuit 1701 in accordance with the invention resulting in a 480 line static vertical resolution.
• alternate lines are decimated at deeimator 1702 to result in a 2:1 interlaced 525 line signal and provided to a diagonal filter 1703.
• the 28 megahertz sampling output of the diagonal filter is then provided to a decimation circuit 1704 for decimating alternate samples on alternate lines leaving a quincunx sample structure at a 14 megahertz sampling rate.
• the resulting samples are stored in memory and read out at a different rate effectuating a 3:2 sample compression in the time domain at time compression circuit 1705.
• the time compressed samples are then mixed with chrominance and any data/audio signals for transmission at multiplexer 1706.
• Skew-symmetric filter portion 1710 then is shared by the processed luminance and chrominance signals.
• the chrominance processing is similar to that for luminance processing but recognizes that U/V component signals are transmitted every other line, and chrominance is normally compressed, in accordance with the B-MAC transmission format, at a ratio of 3:1. Consequently, a chrominance input of the same number of lines in either interlaced or. non-interlaced format as the luminance signal is provided to a vertical filter/interpolator 1801 to achieve a 120 line dynamic or 180 line static chrominance resolution in picture height. In the horizontal dimension, the achieved chrominance reso ⁇ lution can be up to 300 lines of picture width. Because every other line is processed, a line decimation circuit 1802 for U and V compo ⁇ nents is operated at a 4:1 ratio.
• the output of the line decimation circuit is provided to a horizontal filter 1803 centered at 2.5 mega ⁇ hertz.
• High frequency color samples output from the horizontal filter are then time compressed at 3:1 according to B-MAC transmission standards at time compression circuit 1804, the color signals are then mixed for transmission, that is, U and V components are mixed with luminance signals at multiplexer 1706 and transmitted every other line as in standard B-MAC with audio or data channels also input to multiplexer 1706.
• the same skew-symmetric filter portion 1710 may be applied to the combined signal prior to transmission.
• a complimentary skew-symmetric filter portion 1901 at 10.7 megahertz receives the HMB-MAC signal. Consequently, aliasing of the composite signal is eliminated.
• the output of the complimen ⁇ tary skew-symmetric filter portion 1901 is sampled at a 21 megahertz rate and is provided to a luminance processing path and a chrominance processing path. The result is a figure of five or quincunx sample structure.
• Luminance samples are time-expanded 3:2 at time expansion circuit 1902. The output is then provided to a diagonal filter/interpolator stage 1903 which provides a digital output with missing alternate samples replaced in alternate lines.
• chrominance samples are time expanded by 3:1 at time expansion circuit 1904 and the time- expanded samples at 7 megahertz are provided to a vertical filter/ interpolator 1905 for providing useable R-Y and B-Y chrominance outputs. These may be modulated at modulator 1906 and provided to a shared digital to analog converter 1907 for providing luminance and chrominance outputs Y and C or separately output to high definition television receiver apparatus.
• a high definition television receiver is shown in block diagram form according to Figure 20.
• Luminance samples 4 output from the decoder of Figure 19 are input to the high definition receiver along with separate R-Y and B-Y inputs.
• a scan conversion apparatus 2001 comprising in combination a field store 201, a motion detector 2003 and an interpo ⁇ lating algorithm processor 2004.
• the intent is to provide line doubling in the vertical dimension as expeditiously as possible.
• Scan conver ⁇ sion apparatus may be employed as disclosed in application Serial No. 255,238, filed October 11, 1988 and incorporated herein by refer ⁇ ence.
• another luminance signal path comprises delay and compression circuits 2005, 2006 for 2:1 compression which is mixed with the scan converter output via compression circuit 2007 at multiplexer 2008 for display.
• Chrominance information is interpolated in the vertical dimen ⁇ sion at vertical interpolator 2010 compressed 4:1 at compression cir ⁇ cuit 2011 and mixed with the chrominance input signal for display at multiplexer 2012.
• a high definition B-MAC signal 2101 may be received and displayed alternatively to a video cassette recoder output 2102 or a land-line cable input 2103..
• a high definition television receiver is shown which, responsive to a user-selected input entered via selector 2104, applies, for example, the already described adaptive scan con ⁇ version methods for line doubling at scan converter 2105 and so dis ⁇ plays a high definition 16:9 aspect ratio image on the receiver.
• an of -the-air broadcast television signal 2108 may be received by antenna, tuned at tuner 2109, decoded if necessary at NTSC decoder 2110 and provided via the same scan conversion apparatus 2105 for display.
• a terrestrial high definition decoder 2111 is required if the broadcast signal 2108 is high definition. Consequently, a user equipped with a high definition television receiver is able to improve resolution of a displayed image regardless of whether the received signal is high definition, standard NTSC low resolution, or encoded in high or low resolution multiplexed analog components format.

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• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Television Systems (AREA)
• Color Television Systems (AREA)
• Compression Or Coding Systems Of Tv Signals (AREA)

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• 1989
  • 1989-11-16 CN CN89109266A patent/CN1045674A/zh active Pending
  • 1989-11-16 CA CA002003136A patent/CA2003136A1/en not_active Abandoned
  • 1989-11-16 WO PCT/US1989/005044 patent/WO1990006038A1/en not_active Application Discontinuation
  • 1989-11-16 BR BR898907776A patent/BR8907776A/pt unknown
  • 1989-11-16 AU AU47420/90A patent/AU4742090A/en not_active Abandoned
  • 1989-11-16 EP EP90901153A patent/EP0571362A1/de not_active Withdrawn
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