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Topic: Chrominance


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YUV
RGB
YIQ
PAL

In the News (Wed 26 Jun 19)

  
  Chrominance - Wikipedia, the free encyclopedia
Chrominance (chroma for short) comprises the two components of a television signal that encode color information.
The presence of chrominance in a video signal is signalled by a "color burst" signal transmitted on the "front porch," just after horizontal synchronization and before each line of video starts.
Chrominance is represented by the U-V color plane in a PAL and SECAM video signals, and by the I-Q color plane in NTSC.
en.wikipedia.org /wiki/Chrominance   (324 words)

  
 Chrominance format - Wikipedia, the free encyclopedia
Chrominance is sampled at half the horizontal rate of luminance, but at the same vertical rate.
Chrominance is sampled at one-quarter the horizontal rate of luminance, but at the same vertical rate.
Technically an abuse of the notation, this indicates that chrominance is sampled at half the rate of luminance in both the vertical and horizontal directions.
en.wikipedia.org /wiki/Chrominance_format   (266 words)

  
 Facts about topic: (Chrominance)   (Site not responding. Last check: 2007-10-08)
Chrominance (chroma for short) comprises the two components of a television (A telecommunication system that transmits images of objects (stationary or moving) between distant points) signal that encode color information.
The presence of chrominance in a video signal is signalled by a "color burst (additional info and facts about color burst) " signal transmitted on the "front porch (A porch for the front door)," just after horizontal synchronization and before each line of video starts.
Chrominance is represented by the U-V (additional info and facts about U-V) color plane in a PAL and SECAM video signals, and by the I-Q (additional info and facts about I-Q) color plane in NTSC.
www.absoluteastronomy.com /encyclopedia/c/ch/chrominance.htm   (330 words)

  
 [No title]   (Site not responding. Last check: 2007-10-08)
Chrominance demodulator 220 receives the gain-adjusted chrominance signal from amplifier 210 and, according to an exemplary embodiment, multiplies the gain-adjusted chrominance signal by quadrature phase sinusoid signals provided from quadrature oscillator 250 to thereby generate and output demodulated chrominance signals.
The chrominance processing arrangement (200) of claim 12, further comprising: oscillating means (250) for generating phase signals; and wherein the at least one output signal of the burst accumulating means (240) controls the oscillating means (250), and the phase signals of the oscillating means (250) control the chrominance demodulating means (220).
The chrominance processing arrangement (200) of claim 8, wherein the means (240) comprises a plurality of accumulators (305,310) for generating at least two values; and the at least one output signal is generated in response to comparing signs of the at least two values.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=03/51057.030619&ELEMENT_SET=DECL   (4409 words)

  
 CHROMINANCE   (Site not responding. Last check: 2007-10-08)
Chrominance comprises the two components of a television signal that encode color information.
In analog television, chrominance is encoded into a video signal using a special "subcarrier" frequency, which, depending on the standard, can be either quadrature-amplitude or frequency modulated.
It is licensed under the GNU free documentation license.
www.yotor.org /wiki/en/ch/Chrominance.htm   (282 words)

  
 Instantaneous neutral colors in dither-quantized color television - Patent 4652905
Chrominance elements, corresponding to combinations of I and Q, are therefore similar to I elements in size and shape and are quantized according to MN chrominance values, called herein transmittable chrominance vectors, abbreviated tcv's.
Consequently, chrominance (I.sub.z,Q.sub.z) is transmitted as a larger number of T.sub.101 samples, a smaller number of T.sub.103 samples, and occasional T.sub.104 samples, all interleaved in a manner that depends on the DI and DQ dither patterns.
Chrominance near a boundary between neighborhoods is always sent as a mixture of tcv's that changes gradually across the boundary, thereby avoiding artificial color contours.
www.freepatentsonline.com /4652905.html   (6614 words)

  
 Basic principles of compatible colour: The NTSC system (from television) --  Britannica Concise Encyclopedia - The ...
Chrominance, defined as that part of the colour specification remaining when the luminance is removed, is a combination of the two independent quantities, hue and saturation.
Chrominance may be represented graphically in polar coordinates on a colour circle (as shown in the diagram), with saturation as the radius and hue as the angle.
This chrominance, or colour, burst consists of a minimum of eight full cycles of the chrominance subcarrier and is placed on the “back porch” of the blanking pulse, immediately after the horizontal synchronization pulse.
www.britannica.com /ebc/article-235339?tocId=235339   (2274 words)

  
 NTSC Color Encoding and Decoding   (Site not responding. Last check: 2007-10-08)
The final result is that the chrominance signal consists of a 3.58 Mhz amplitude modulated waveform whose amplitude represents the saturation of the color and whose phase represents the color itself (the hue).
But since the portion of the upper chrominance sideband more than 0.5 Mhz from the subcarrier has been removed for NTSC broadcasts, no cancellation occurs in either the I or Q demodulator when the corresponding information in the lower chrominance sideband is encountered.
To be exact, "chrominance" and "chroma" differ in that they imply different relationships between signal strength and the vividness of the color as viewed.
members.aol.com /ajaynejr/colordec.htm   (6042 words)

  
 Tektronix MBD: Applications > NTSC Video Meas: Glossary
The difference between the gain of the chrominance portion of the video signal and the gain of the luminance portion as they pass through a system.
Variation in the gain of the chrominance signal as the luminance signal on which it rides is varied from blanking to white level.
Variation in the phase of the chrominance subcarrier as the luminance signal on which it rides is varied from blanking to white level.
www.tek.com /Measurement/App_Notes/NTSC_Video_Msmt/glossary.html   (666 words)

  
 [2.0] JPEG Image Compression   (Site not responding. Last check: 2007-10-08)
Chrominance actually amounts to two values, one that describes the "hue", or specific color within a linear range of colors, and the other that describes the "saturation", or intensity of the color.
By the way, although chrominance is specified by two values, the actual values used aren't precisely the hue and the saturation.
The only differences are that chrominance data may be decimated, as discussed earlier, and the chrominance values may have their own Q-tables.
www.vectorsite.net /ttdcmp2.html   (6290 words)

  
 Low-frequency converter for carrier chrominance signal - Patent 4860120
When the carrier chrominance signal supplied to the input 1 includes jitter during dubbing, such jitter is also included in the color burst signal extracted from the burst gate 3 and the signal which is synchronous with the horizontal synchronizing signal supplied to the input 2.
Hence the jitter of the carrier chrominance signal is cancelled in the multiplier 16, by the jitter in the output signal from the BPF 15.
Although the signal having the frequency of the sum of frequencies of the carrier chrominance signal and the low-frequency conversion chrominance signal is inputted in the multiplier 16, as the main balanced modulator, together with the carrier chrominance signal, it may be replaced by a signal based on the frequency difference.
www.freepatentsonline.com /4860120.html   (3500 words)

  
 Digital chrominance signal processing system - Patent 4743961   (Site not responding. Last check: 2007-10-08)
The delayed chrominance signal is supplied to a chroma inverter 110 in which the phase of the subcarrier thereof is inverted and the resulting inverted chrominance signal C' is then combined with the luminance signal Y by an adder 106.
3,564,123, comprises input and output transformers 111 and 112, with the chrominance signal C being supplied to a terminal 113 of the input transformer 111 and a chrominance signal C', the phase of which is inverted, as required, being developed at a terminal 114 of the output transformer 112.
Consequently, the chrominance signal applied to the input side of the output transformer 112 is made to have an opposite polarity to the preceding polarity so that when the command signal is at "H" level, the phase-inverted chrominance signal C' is developed at the output terminal 114.
www.freepatentsonline.com /4743961.html   (3439 words)

  
 Tektronix MBD: Applications > NTSC Video Meas: Intermediate NTSC Video Testing
A 12.5T chrominance pulse, shown in the center of this display, is used to evaluate chrominance-to-luminance gain and delay errors.
The upward bowing of the baseline (the negative waveform peaks) indicates that chrominance is reduced relative to luminance.
A sinusoidal distortion of the chrominance pulse baseline indicates that chrominance is either advanced or delayed relative to luminance.
www.tek.com /Measurement/App_Notes/NTSC_Video_Msmt/videotesting2.html   (2075 words)

  
 United States Patent Application: 0040046894   (Site not responding. Last check: 2007-10-08)
The method of claim 1 wherein step (d) the color pixels in the chrominance signals are selected so that color pixels to be averaged do not extend beyond the boundaries of the textured region.
The method of claim 1 wherein step (e) the color pixels in the chrominance signals are selected so that the averaged colored pixels have corresponding chrominance values to the chrominance values of the pixel to be noise-cleaned.
It should now be clear that the color pixels in the chrominance signals are selected and modified so that the averaged colored pixels have corresponding chrominance values to the chrominance values of the pixel to be noise-cleaned.
appft1.uspto.gov /netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1="20040047420".PGNR.&OS=DN/20040047420&RS=DN/20040047420   (2767 words)

  
 Glossary   (Site not responding. Last check: 2007-10-08)
Chrominance is derived from the I and Q signals in the NTSC television system and the U and V signals in the PAL television system.
The two chrominance signals I and Q (in-phase and quadrature, respectively) are two-phase amplitude-modulated; the I component modulates the subcarrier at an angle of 0 degrees and the Q component modulates it at 90 degrees.
Y is the luminance signal and R-Y and B-Y are the chrominance signals.
biology.ncsa.uiuc.edu /library/SGI_bookshelves/SGI_Admin/books/Combiner_UG/sgi_html/go01.html   (3740 words)

  
 [No title]   (Site not responding. Last check: 2007-10-08)
In NTSC broadcast, the modulated chrominance, whose spectrum is shown in Figure, is transmitted as I and Q signals.
After bandpass filtering, the chrominance is passed to an automatic- gain-control circuit (abbreviated ACC for Automatic Color Control), which uses a negative feedback loop to regulate the color burst (and thus the chrominance) at a fixed output amplitude over a wide range of possible input amplitudes.
Multiplying the chrominance with the color subcarrier produces undesired signals in a frequency band that is centered at twice the color-subcarrier frequency, or 7.16 MHz.
www.ece.ucdavis.edu /~lewis/parker   (4554 words)

  
 Economical high-definition television using a modulated-signal combination - Patent 4641179   (Site not responding. Last check: 2007-10-08)
The chrominance information is recovered from the transmitted signal by first notch filtering the transmitted high-definition signal to remove energy existing between the two sidebands of the QAM high-frequency chrominance information, and then, demodulating at the carrier frequency.
Advantageously, high-definition chrominance components are each separately comb filtered to help reduce cross-effects and then modulated and amplified to broadcast power and carrier frequency and, then, combined with a similar modulated and amplified high-definition luminance signal for providing a broadcast signal.
The other chrominance component and the low-frequency segment of the one chrominance component are QAM modulated with the result being frequency translated to the carrier frequency.
www.freepatentsonline.com /4641179.html   (3717 words)

  
 [No title]   (Site not responding. Last check: 2007-10-08)
The waveform generator provides chrominance identification waveforms for insertion into the encoded SECAM signal and includes a timing circuit which determines a sequence of identification line intervals within vertical blanking intervals from SECAM vertical and horizontal sync signals provided by the encoder.
The waveform generator includes memory for storing digital samples representing the chrominance identification waveforms; a selector for selecting the digital samples for the corresponding chrominance identification waveform from memory; and a converter for converting the selected digital samples to an analog representation of the corresponding chrominance identification waveform.
for storing digital samples representing the chrominance identification waveforms; a selector for selecting the digital samples for the corresponding chrominance identification waveform from memory; and a converter for converting the selected digital samples to an analog representation of the corresponding chrominance identification waveform.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=99/55094.991028&ELEMENT_SET=DECL   (2365 words)

  
 Method and apparatus for compensation of luminance defects caused by chrominance signal processing   (Site not responding. Last check: 2007-10-08)
To thаt finish, the chrominance is encoded and decoded аgаin in the encoder.
A соrreсtiоn signal is derived frоm the decoded chrominance signal and is used during the encoding of the luminance.
The macroblocks whiсh аre motion-compensated for prediction аre bаsed оn the likewise decoded chrominance signal and оn the decoded, corrected luminance signal.
www.patentalert.com /docs/530/z53019348.shtml   (240 words)

  
 Notes on Video Output
The chrominance signal is defined at a frequency of 3.58MHz.
The hue is determined by the phase shift of the chrominance signal, but to determine the phase there must be a reference signal.
Although chrominance is actually made up of separate R-Y and B-Y signals, it is convenient to think of the addition of these signals as a single waveform that shifts phase to create a continuous range of hues.
www.xmission.com /~trevin/atari/video_notes.html   (1885 words)

  
 [No title]   (Site not responding. Last check: 2007-10-08)
Chrominance can be further broken down into two properties of colour: hue and saturation.
An analog circuit that allows the luminance and chrominance parameters in a video camera to be controlled.
The 3.58 MHz signal that is modulated by the colour information to form a chrominance signal.
www1.discreet.com /site/faq.nsf/ca8bb2ebce61f15585256ac70050bf2a/44a3d9c02cef14e2852564270003a2bb   (1628 words)

  
 video test
When testing a videotape recorder, it may be necessary to use a reduced amplitude (60 IRE) Multiburst signal otherwise the high multiburst frequencies may interfere with the FM recording circuits of the videotape recorder.
The 3-level chrominance portion is used to detect chrominance-to-luminance intermodulation, chrominance nonlinear gain distortion, and chrominance nonlinear phase distortion.
Chroma Noise is a 100 IRE (714.29 mV) peak-to-peak amplitude red chrominance signal (chrominance phase of 103.5 degrees) modulated on a 50 IRE (357.14 mV) pedestal.
aelinik.free.fr /networking1.htm   (3863 words)

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