CA1245343A - Luminance/chrominance separation circuitry - Google Patents
Luminance/chrominance separation circuitryInfo
- Publication number
- CA1245343A CA1245343A CA000514637A CA514637A CA1245343A CA 1245343 A CA1245343 A CA 1245343A CA 000514637 A CA000514637 A CA 000514637A CA 514637 A CA514637 A CA 514637A CA 1245343 A CA1245343 A CA 1245343A
- Authority
- CA
- Canada
- Prior art keywords
- signal
- signals
- delay
- chrominance
- luminance signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000926 separation method Methods 0.000 title description 2
- 239000002131 composite material Substances 0.000 claims abstract description 29
- 230000000295 complement effect Effects 0.000 claims description 3
- 239000003086 colorant Substances 0.000 claims description 2
- 230000001747 exhibiting effect Effects 0.000 claims 1
- 230000003044 adaptive effect Effects 0.000 abstract description 4
- 230000003111 delayed effect Effects 0.000 description 6
- 230000001934 delay Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- BHMLFPOTZYRDKA-IRXDYDNUSA-N (2s)-2-[(s)-(2-iodophenoxy)-phenylmethyl]morpholine Chemical compound IC1=CC=CC=C1O[C@@H](C=1C=CC=CC=1)[C@H]1OCCNC1 BHMLFPOTZYRDKA-IRXDYDNUSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/77—Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase
- H04N9/78—Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase for separating the brightness signal or the chrominance signal from the colour television signal, e.g. using comb filter
Abstract
Abstract of the Disclosure A frame comb type composite video decoder which does not require motion adaptive processing circuitry generates low frequency luminance signal components from one field of composite video signal. The high frequency luminance component is derived from two lines of composite video signal from each of two fields disposed before and after the field from which the low frequency luminance signals is developed.
Description
3~3 -l- RCA 82,352 LUMINANCE/CHROMINANCE SEPARATION CIRCUITRY
This invention relates to circuitry ~or separating luminance and chrominance signal components from a composite video signal.
In order to utillze the full bandwidth of the luminance component of ~omposi-te video signals special circuitry is re~uired to separate it from the chrominance component which shares the high freguency band of the composite signal. Conventional circuitry used to perform this function is in~the form of transversal filters, the most common of which is the interline comb filter which obtains the sums and differences of the composite signals delayed, with respect to each other, by one or two integral horlzontal line intervals. Interline comb filters perform relatively satisfactorily even when the video signal contains image motion. Interline comb filters, however, produce a particularly objectionable artifact known as "hanging dots". Hanging dots are observed as a line of bright and dark spots reproduced along horizontal edges that undergo a color transition and are caused by incomplete cancellation o chrominance in the luminance signal.
A second type of wideband luminance/chrominance separator is the frame comb filter which obtains the sums and differences of composite video signals delayed relative to each other by integral frame intervals. Frame cor~ filters do not exhibit any of the undesirable artifacts produced by interline comb filters if the images represented by the video signal contain no image motion.
However, when images do include motion, the frame comb filters generate phantom images and relatively large areas of color dots along moving edges. Numerous methods have been proposed which eliminate motion induced artifacts, all of which require circuitry to detect the occurrence of motion. In general, it is difficult to distinguish between signal no.ise and image motion, thus, the performance of motion adaptive frame comb filters is only ~.
~53~3
This invention relates to circuitry ~or separating luminance and chrominance signal components from a composite video signal.
In order to utillze the full bandwidth of the luminance component of ~omposi-te video signals special circuitry is re~uired to separate it from the chrominance component which shares the high freguency band of the composite signal. Conventional circuitry used to perform this function is in~the form of transversal filters, the most common of which is the interline comb filter which obtains the sums and differences of the composite signals delayed, with respect to each other, by one or two integral horlzontal line intervals. Interline comb filters perform relatively satisfactorily even when the video signal contains image motion. Interline comb filters, however, produce a particularly objectionable artifact known as "hanging dots". Hanging dots are observed as a line of bright and dark spots reproduced along horizontal edges that undergo a color transition and are caused by incomplete cancellation o chrominance in the luminance signal.
A second type of wideband luminance/chrominance separator is the frame comb filter which obtains the sums and differences of composite video signals delayed relative to each other by integral frame intervals. Frame cor~ filters do not exhibit any of the undesirable artifacts produced by interline comb filters if the images represented by the video signal contain no image motion.
However, when images do include motion, the frame comb filters generate phantom images and relatively large areas of color dots along moving edges. Numerous methods have been proposed which eliminate motion induced artifacts, all of which require circuitry to detect the occurrence of motion. In general, it is difficult to distinguish between signal no.ise and image motion, thus, the performance of motion adaptive frame comb filters is only ~.
~53~3
-2- RCA 82,352 slightly better than that of interline comb filters and at the expense of significantly more circuit hardware.
Finally, a third type of transversal filter for separating the luminance and chrominance components from composite video signals takes the form of, e.g., output weighted finite impulse response filters. These filters require a large number of frame delays, for example seven, and though they do not require motion adaptive circuitry, are prohibitively expensive for use in consumer TV
receivers.
The present invention is directed to luminance/chrominance separating apparatus which exhibits superior performance, does not require motion adaptive circuitry, and is relatively cost effective.
Separating apparatus in accordance with the present invention includes means for concurrently providing composite video signals from different ones of successive fields. Filter means, responsive to only one of said concurrently provided signals, produce a relatively low frequency luminance signal. Additional means, responsive only to others of said concurrently provided signals, produce a relatively high frequency luminance signal substantially free from chrominance component accompaniment. The additional means includes first signal combining means responsive to a pair of composite video signals, from a field different from the field occupied by said one signal, with respective chrominance components having an antiphase subcarrier relationship relative to each other when representing like colors. A second signal combining means, responsive to said relatively low frequency luminance signal and said relatively high frequency luminance signal, develops a wideband luminance signal output.
In the accompanying drawing:
FIGURE 1 is a pict~rial spatio-temporal representation of a portion of composite video signals for portions of several video sig~al field intervals.
~2~`534~3
Finally, a third type of transversal filter for separating the luminance and chrominance components from composite video signals takes the form of, e.g., output weighted finite impulse response filters. These filters require a large number of frame delays, for example seven, and though they do not require motion adaptive circuitry, are prohibitively expensive for use in consumer TV
receivers.
The present invention is directed to luminance/chrominance separating apparatus which exhibits superior performance, does not require motion adaptive circuitry, and is relatively cost effective.
Separating apparatus in accordance with the present invention includes means for concurrently providing composite video signals from different ones of successive fields. Filter means, responsive to only one of said concurrently provided signals, produce a relatively low frequency luminance signal. Additional means, responsive only to others of said concurrently provided signals, produce a relatively high frequency luminance signal substantially free from chrominance component accompaniment. The additional means includes first signal combining means responsive to a pair of composite video signals, from a field different from the field occupied by said one signal, with respective chrominance components having an antiphase subcarrier relationship relative to each other when representing like colors. A second signal combining means, responsive to said relatively low frequency luminance signal and said relatively high frequency luminance signal, develops a wideband luminance signal output.
In the accompanying drawing:
FIGURE 1 is a pict~rial spatio-temporal representation of a portion of composite video signals for portions of several video sig~al field intervals.
~2~`534~3
-3- RCA ~2,352 FIGURE 2 is a block diagram of luminance/chrominance separating apparatus embodying the present invention.
~eferring ko FIGURE 1, the vertical columns of dots represent portions of successive fields of video sig~al. The dots represent horizontal lines of video signal (looklng end on with the lines going into the paper). The offset in dot positions between adjacent fields illustrates the interlaced scanning offset as displayed in the reproduced image. The + and - signs adjacent each dot indicate the relative phase of the chrominance subcarrier line-to-line and field to-field.
Assume that the current signal output by the apparatus of the present invention corresponds to horizontal llne 0. The low frequenc~ portion of the decoded luminance signal is derived by low-pass filtering composite video signals from line 0. The high frequency portion of the luminance signal is derived by additively combining equal portions of signal from lines A, B, D and E. The combined signal is high-pass filtered and added to the low frequency contribution from line 0. The spatial average of these signals falls on point 0, and thus, is consistent with combining it with the low frequency contribution from line 0~
The composite video signals from lines A and E
have a complementary chrominance phase relationship with respect to the signals from lines B and D. Thus, when the additively combined signals from lines A and B are further additively combined with the combined signals from lines D
and E, the chrominance components cancel, leaving only the luminance component. No hanging dots result for the following reason. Adding signals from lines A and B or lines D and E is tantamount to performing interline comb filtering. As such, either combination will produce hanging dots under appropriate signal conditions.
However, ~he hanging dots attendant the combination of signals from lines A and B will be antiphase with hanging 3~3
~eferring ko FIGURE 1, the vertical columns of dots represent portions of successive fields of video sig~al. The dots represent horizontal lines of video signal (looklng end on with the lines going into the paper). The offset in dot positions between adjacent fields illustrates the interlaced scanning offset as displayed in the reproduced image. The + and - signs adjacent each dot indicate the relative phase of the chrominance subcarrier line-to-line and field to-field.
Assume that the current signal output by the apparatus of the present invention corresponds to horizontal llne 0. The low frequenc~ portion of the decoded luminance signal is derived by low-pass filtering composite video signals from line 0. The high frequency portion of the luminance signal is derived by additively combining equal portions of signal from lines A, B, D and E. The combined signal is high-pass filtered and added to the low frequency contribution from line 0. The spatial average of these signals falls on point 0, and thus, is consistent with combining it with the low frequency contribution from line 0~
The composite video signals from lines A and E
have a complementary chrominance phase relationship with respect to the signals from lines B and D. Thus, when the additively combined signals from lines A and B are further additively combined with the combined signals from lines D
and E, the chrominance components cancel, leaving only the luminance component. No hanging dots result for the following reason. Adding signals from lines A and B or lines D and E is tantamount to performing interline comb filtering. As such, either combination will produce hanging dots under appropriate signal conditions.
However, ~he hanging dots attendant the combination of signals from lines A and B will be antiphase with hanging 3~3
-4- RCA 82,352 dots attendant the combined signals from lines D and E and the combination of both tends to cancel the hanging dots.
The more objec-tionable motion-induced artifacts produced by frame comb filters occur in the lower band of fre~uencies of the frame filtered signal. In the present invention, the low frequency luminance signal, being derived Erom a sinyle signal, i.e. line 0, and not being the combination of signal from adjacent frames, exhibits no low frequency motion-induced artifacts in the reproduced image.
Color dots trailing a moving edge do not occur for reasons similar to the cancellation of hanging dots.
Color dots arise due to imperfect cancellation of the luminance component in the chrominance signal. The chrominance signal is generated by adding the complements of signals from lines B and D to signals from lines A and E. Complementing signals from lines B and D inverts the phase of the chrominance signal therein to be in phase with the chrominance signal from lines A and E. The chrominance components from all four lines add constructively. The inverted luminance signal from lines B and D cancel the non-inverted luminance signal from lines A and E. The chrominance signal, C0, is given by the e~uation C0 = (CA-cB-cD+cE)/ (1) wherein CA, CB, CD and CE represent the chrominance signal components from lines A, B, D and E respectively.
If the signal is redundant between successive lines in a frame and between like pixels in successive frames, the chrominance signal C0 is just equal to the input chrominance signal C. If there is motion between frames, the bandwidth of the chrominance signal will be reduced at the moving edges, but this does not significantly adversely affect reproduced image quality because in general, the eye cannot discern rapidly mo~ing edges anyway.
Next, consider the luminance component which contaminates the chrominance output due to dots trailing a 53~
The more objec-tionable motion-induced artifacts produced by frame comb filters occur in the lower band of fre~uencies of the frame filtered signal. In the present invention, the low frequency luminance signal, being derived Erom a sinyle signal, i.e. line 0, and not being the combination of signal from adjacent frames, exhibits no low frequency motion-induced artifacts in the reproduced image.
Color dots trailing a moving edge do not occur for reasons similar to the cancellation of hanging dots.
Color dots arise due to imperfect cancellation of the luminance component in the chrominance signal. The chrominance signal is generated by adding the complements of signals from lines B and D to signals from lines A and E. Complementing signals from lines B and D inverts the phase of the chrominance signal therein to be in phase with the chrominance signal from lines A and E. The chrominance components from all four lines add constructively. The inverted luminance signal from lines B and D cancel the non-inverted luminance signal from lines A and E. The chrominance signal, C0, is given by the e~uation C0 = (CA-cB-cD+cE)/ (1) wherein CA, CB, CD and CE represent the chrominance signal components from lines A, B, D and E respectively.
If the signal is redundant between successive lines in a frame and between like pixels in successive frames, the chrominance signal C0 is just equal to the input chrominance signal C. If there is motion between frames, the bandwidth of the chrominance signal will be reduced at the moving edges, but this does not significantly adversely affect reproduced image quality because in general, the eye cannot discern rapidly mo~ing edges anyway.
Next, consider the luminance component which contaminates the chrominance output due to dots trailing a 53~
-5- RCA 82,352 movin~ edge. The luminance component, Loc/ in the chrominance output is given by the equation Loc = (LA-LD+LE LB)/ (2) wherein LA, LD, LE and LB represent the luminance signal components in lines A, D, E and B respectively. If the signal is redundant from line-to-line, which holds true for the majority of lmages, and the signal is the same for corresponding pixels in successive frames, then the value LoC is zero.
Next ccnsider that horizontal image motion occurs between frames M and M~l. The differences (LA-LD) and (LE-LB) in equation (2) will in general be equal but of opposite polarlty and so will cancel. Finally, considering vertical motion, the terms in equation (2) may be rearranged to form the sum of the differences (LA-LB) and (LE-LD), which difference will be equal for vertical motion but of opposite polarity, and so also cancel.
Thus, trailing color dots are not produced following moving edges in the image.
FIGURE 2 illustrates circuitry according to the invention for performing the aforedescribed composite video signal separating algorithm. In FIGURE 2, an input composite video signal is applied to terminal 10. The composite video signal at terminal 10 is coupled to cascade-connected delay elements 12, 14, 16 and 18 which respectively provide at their output terminals signal delays of one, two hundred sixty three, five hundred twenty five and five hundred twenty six horizontal line intervals relative to the signal at terminaI 10. Signal at the input to delay element 12 and delayed signals from the outputs of delay elements 12, 14, 16 and 18 correspond to signals from lines A, B, 0, D and E respectively in FIGURE 1.
Composite video signals from terminal 10 and delayed composite video signal from the respective output terminals of delay elements 12, 16 and 18 are coupled to signal com~iner 30 which additively combines the four siynals to produce a luminance signal which is applied to , . . .
~5343
Next ccnsider that horizontal image motion occurs between frames M and M~l. The differences (LA-LD) and (LE-LB) in equation (2) will in general be equal but of opposite polarlty and so will cancel. Finally, considering vertical motion, the terms in equation (2) may be rearranged to form the sum of the differences (LA-LB) and (LE-LD), which difference will be equal for vertical motion but of opposite polarity, and so also cancel.
Thus, trailing color dots are not produced following moving edges in the image.
FIGURE 2 illustrates circuitry according to the invention for performing the aforedescribed composite video signal separating algorithm. In FIGURE 2, an input composite video signal is applied to terminal 10. The composite video signal at terminal 10 is coupled to cascade-connected delay elements 12, 14, 16 and 18 which respectively provide at their output terminals signal delays of one, two hundred sixty three, five hundred twenty five and five hundred twenty six horizontal line intervals relative to the signal at terminaI 10. Signal at the input to delay element 12 and delayed signals from the outputs of delay elements 12, 14, 16 and 18 correspond to signals from lines A, B, 0, D and E respectively in FIGURE 1.
Composite video signals from terminal 10 and delayed composite video signal from the respective output terminals of delay elements 12, 16 and 18 are coupled to signal com~iner 30 which additively combines the four siynals to produce a luminance signal which is applied to , . . .
~5343
-6- RCA 82,352 filter 26. Filter 26 may be a high-pass filter, band-pass filter or a sampled data filter wi-th a general cosinusoidal transfer function. Filter 26 attenuates signals in the fre~uency band portion of the composite video signal which is not normally occupied by the chrominance component. The signal output of filter 26 is a high fre~uency luminance signal, which signal is coupled to one input of adder 28.
Delayed composite video signal from delay element 14 is coupled to the filter 24. Filter 24 may be a low-pass filter o~ a sampled data filter with a general cosinusoidal transfer function. Filter 2~ attenuates signals in the fre~uency band portion of the composite video signal normally occupied by the chrominance component. In general, filters 24 and 26 have complementary transfer functions in the band of fre~uencies occupied by composite video signal.
The signal provided from filter 24 is low frequency luminance signal and is coupled to a second input of adder 28. Adder 2~ produces a wideband luminance signal.
Nominally, the four signals which are combined in element 30 are we~ighted by a factor of 1/4 before being applied to signal combiner 30 so that combiner 30 produces a normalized signal. Alternatively, the output signal from signal combiner 30, or the output signal from filter 26, may be weighted by 1/4 to normalize the signal. Note, however, that high freg~lency luminance peaking may be achieved by weighting the signal from filter 26 by a larger factor, e.g. 1/2.
Composite video signal from input termlnal 10 and delayed composite video signals from the outputs of delay elements 12, 16 and 18 are coupled to si~nal combiner 20. Signal combiner 20 additively combines signal ~rom inp~t terminal 10 and delay element 18 with the inverse polarity signal from delay elements 12 and 16 to produce a chrominance signal includin~ low ~reguency motion-induced luminance contamination. The si~nal S3~3
Delayed composite video signal from delay element 14 is coupled to the filter 24. Filter 24 may be a low-pass filter o~ a sampled data filter with a general cosinusoidal transfer function. Filter 2~ attenuates signals in the fre~uency band portion of the composite video signal normally occupied by the chrominance component. In general, filters 24 and 26 have complementary transfer functions in the band of fre~uencies occupied by composite video signal.
The signal provided from filter 24 is low frequency luminance signal and is coupled to a second input of adder 28. Adder 2~ produces a wideband luminance signal.
Nominally, the four signals which are combined in element 30 are we~ighted by a factor of 1/4 before being applied to signal combiner 30 so that combiner 30 produces a normalized signal. Alternatively, the output signal from signal combiner 30, or the output signal from filter 26, may be weighted by 1/4 to normalize the signal. Note, however, that high freg~lency luminance peaking may be achieved by weighting the signal from filter 26 by a larger factor, e.g. 1/2.
Composite video signal from input termlnal 10 and delayed composite video signals from the outputs of delay elements 12, 16 and 18 are coupled to si~nal combiner 20. Signal combiner 20 additively combines signal ~rom inp~t terminal 10 and delay element 18 with the inverse polarity signal from delay elements 12 and 16 to produce a chrominance signal includin~ low ~reguency motion-induced luminance contamination. The si~nal S3~3
-7~ RCA 82,352 produced by signal combiner 20 is coupled to the filter 22 which attenuates signals outside the band of frequencies normally occupied by chrominance sig,nals to produce a generally contamination-free chrominance signal.
If the composite video signal is a sampled signal occurring at four times the color subcarrier fre~uency, and if the samples are formed by a sampling clock phase locked to the color subcarrier and aligned with the phases of the color difference signals modulating the subcarrier, then the sequences of samples represent interleaved color difference signal samples. Under these circumstances, signal combiner 20 may be utilized to demodulate the chrominance signal by, for example, outputting two of each sequence of four sums. The two sums from each set of four sums may be demultiplexed to separate signal paths corresponding to first and second color difference signals, each of which is applied to a filter. The filters in this case will in general have a low-pass transfer function commensurate with the bandwidth of the color difference signal.
Alternatively, demodulation may be performed by the filter 22 performing a decimation of two of every four samples passed therethrough.
The structure illustrated in FIGURE 2 and the signal representation shown in FIGURE 1 relate primarily to standard NTSC signals. The invention, however, may be practiced on other signal formats such as PAL with appropriate changes in the delay elements. Apparatus for decoding PAL signals, for example, will be similar to the FIGURE 2 apparatus with the following changes. Delay elements 12 and 18 may each be arranged to provide delay intervals of two horizontal line periods and delay elements 14 and 16 may each be arranged to provide delay intervals of six hundred twenty four line intervals.
.
If the composite video signal is a sampled signal occurring at four times the color subcarrier fre~uency, and if the samples are formed by a sampling clock phase locked to the color subcarrier and aligned with the phases of the color difference signals modulating the subcarrier, then the sequences of samples represent interleaved color difference signal samples. Under these circumstances, signal combiner 20 may be utilized to demodulate the chrominance signal by, for example, outputting two of each sequence of four sums. The two sums from each set of four sums may be demultiplexed to separate signal paths corresponding to first and second color difference signals, each of which is applied to a filter. The filters in this case will in general have a low-pass transfer function commensurate with the bandwidth of the color difference signal.
Alternatively, demodulation may be performed by the filter 22 performing a decimation of two of every four samples passed therethrough.
The structure illustrated in FIGURE 2 and the signal representation shown in FIGURE 1 relate primarily to standard NTSC signals. The invention, however, may be practiced on other signal formats such as PAL with appropriate changes in the delay elements. Apparatus for decoding PAL signals, for example, will be similar to the FIGURE 2 apparatus with the following changes. Delay elements 12 and 18 may each be arranged to provide delay intervals of two horizontal line periods and delay elements 14 and 16 may each be arranged to provide delay intervals of six hundred twenty four line intervals.
.
Claims (7)
1. Luminance/chrominance signal component separating apparatus for use with a source of composite video signals inclusive of a luminance signal component and a chrominance signal component comprising modulated color subcarrier waves; said apparatus comprising:
means coupled to said source for concurrently providing composite video signals from different ones of successive fields;
filter means, responsive to only one of said concurrently provided signals, for producing a relatively low frequency luminance signal;
means, responsive only to others of said concurrently provided signals, for producing a relatively high frequency luminance signal substantially free from chrominance component accompaniment; said high frequency luminance signal producing means including a first signal combining means responsive to a pair of composite video signals, from a field different from the field occupied by said one signal, with respective chrominance components having an antiphase subcarrier relationship relative to each other when representing like colors; and second signal combining means, responsive to said relatively low frequency luminance signal and to said relatively high frequency luminance signal for developing a wideband luminance signal output.
means coupled to said source for concurrently providing composite video signals from different ones of successive fields;
filter means, responsive to only one of said concurrently provided signals, for producing a relatively low frequency luminance signal;
means, responsive only to others of said concurrently provided signals, for producing a relatively high frequency luminance signal substantially free from chrominance component accompaniment; said high frequency luminance signal producing means including a first signal combining means responsive to a pair of composite video signals, from a field different from the field occupied by said one signal, with respective chrominance components having an antiphase subcarrier relationship relative to each other when representing like colors; and second signal combining means, responsive to said relatively low frequency luminance signal and to said relatively high frequency luminance signal for developing a wideband luminance signal output.
2. Apparatus in accordance with claim 1, also including means, responsive only to said others of said concurrently provided signals, for producing a chrominance signal output substantially free from luminance signal accompaniment; said chrominance signal output producing means including a third signal combining means, said third signal combining means effecting a subtractive combination of said pair of signals.
3. Apparatus in accordance with claim 2, wherein said signal providing means includes first, second, third and fourth delay devices in cascade, with composite video signals from said source supplied to the input of said first delay device; wherein each of said first and fourth delay devices provide a delay of first duration equal to the duration of a line interval multiplied by a first integer; wherein each of said second and third delay devices provide a delay of a second duration equal to the duration of a line interval multiplied by a second integer, greater than said first integer; and wherein said one signal comprises the output of said second delay device.
4. Apparatus in accordance with claim 3, wherein said others of said concurrently provided signals comprise signals appearing at the input to said first delay device, and at the outputs of said first, third and fourth delay devices; and wherein the delay provided between the input of said first delay device and the output of said third delay device is equal to an integral number of frame intervals.
5. Apparatus in accordance with claim 4, wherein said first signal combining means sums all of said others of said concurrently provided signals; and wherein the respective outputs of said first and third delay devices are subtractively combined with said input to said first delay device and said output of said fourth delay device by said third signal combining means.
6. Apparatus in accordance with claim 5, wherein said means for producing said relatively high frequency luminance signal includes a filter, responsive to the output of said first signal combining means, and exhibiting a frequency response characteristic complementary to the frequency response characteristic exhibited by said filter means for producing said relatively low frequency luminance signal.
7. Apparatus in accordance with claim 6, wherein said first integer is one, and said second integer is two hundred and sixty-two.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US759,832 | 1985-07-29 | ||
| US06/759,832 US4684977A (en) | 1985-07-29 | 1985-07-29 | Luminance/chrominance separation circuitry |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1245343A true CA1245343A (en) | 1988-11-22 |
Family
ID=25057130
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000514637A Expired CA1245343A (en) | 1985-07-29 | 1986-07-24 | Luminance/chrominance separation circuitry |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4684977A (en) |
| JP (1) | JP2596731B2 (en) |
| KR (1) | KR940002612B1 (en) |
| CA (1) | CA1245343A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2644762B2 (en) * | 1987-08-07 | 1997-08-25 | 株式会社日立製作所 | Television signal processor |
| US4833526A (en) * | 1988-04-07 | 1989-05-23 | Matsushita Electric Industrial Co., Ltd. | Three dimensional non-adaptive decoder for a PAL color television composite signal |
| JPH0787592B2 (en) * | 1989-03-27 | 1995-09-20 | 三菱電機株式会社 | Motion adaptive luminance signal color signal separation filter |
| JP2007171339A (en) * | 2005-12-20 | 2007-07-05 | Kenwood Corp | Audio signal processing unit |
| EP2451076B1 (en) | 2009-06-29 | 2018-10-03 | Mitsubishi Electric Corporation | Audio signal processing device |
| US9967028B2 (en) * | 2014-10-22 | 2018-05-08 | Indian Institute Of Technology Delhi | System and a method for free space optical communications |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4107736A (en) * | 1971-12-20 | 1978-08-15 | Image Transform, Inc. | Noise reduction system for video signals |
| US4551753A (en) * | 1981-12-17 | 1985-11-05 | Nippon Hoso Kyokai | Picture signal processing system including spatio-temporal filter |
| US4498100A (en) * | 1982-11-26 | 1985-02-05 | Rca Corporation | Apparatus for frame-to-frame comb filtering composite TV signal |
| JPS58212282A (en) * | 1983-05-27 | 1983-12-09 | Hitachi Ltd | Sampling reproducing circuit of color television signal |
| US4598309A (en) * | 1984-05-29 | 1986-07-01 | Rca Corporation | Television receiver that includes a frame store using non-interlaced scanning format with motion compensation |
| US4626895A (en) * | 1984-08-09 | 1986-12-02 | Rca Corporation | Sampled data video signal chrominance/luminance separation system |
-
1985
- 1985-07-29 US US06/759,832 patent/US4684977A/en not_active Expired - Lifetime
-
1986
- 1986-07-24 CA CA000514637A patent/CA1245343A/en not_active Expired
- 1986-07-28 JP JP61175853A patent/JP2596731B2/en not_active Expired - Lifetime
- 1986-07-28 KR KR1019860006149A patent/KR940002612B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR870001644A (en) | 1987-03-17 |
| JPS6226996A (en) | 1987-02-04 |
| JP2596731B2 (en) | 1997-04-02 |
| US4684977A (en) | 1987-08-04 |
| KR940002612B1 (en) | 1994-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5519454A (en) | Luma/chroma separation filter with common delay element for comb filter separation and recursive noise reduction of composite video input signal | |
| JPS59205888A (en) | Device for separating color television signal into intensityinformation and color information | |
| EP0638220B1 (en) | Video signal coding | |
| JP2865758B2 (en) | Device for combining and separating video signal components | |
| EP0549174B1 (en) | Adaptive chrominance filtering control | |
| US4742386A (en) | Method and apparatus for encoding component digital video signals so as to compress the bandwidth thereof, and for decoding the same | |
| US4809060A (en) | Hanging dot reduction arrangement | |
| CA1245343A (en) | Luminance/chrominance separation circuitry | |
| US3871019A (en) | Line sequential color television recording system | |
| JPH07118813B2 (en) | Color video signal encoding method | |
| WO1992002102A1 (en) | Method for decoding television signals | |
| US4636841A (en) | Field comb for luminance separation of NTSC signals | |
| EP0218241A2 (en) | Bi-dimensional comb filter | |
| US5227879A (en) | Apparatus for transmitting an extended definition TV signal having compatibility with a conventional TV system | |
| KR0126472B1 (en) | Adaptive comb filter and its separation method for y/c separation | |
| EP0364967B1 (en) | Luminance/chrominance signal separation circuit for pal color television signal | |
| US5305095A (en) | Method and circuit for encoding color television signal | |
| US4492976A (en) | Line standard conversion circuit for a television signal | |
| WO2004064412A1 (en) | Method and device for separating a chrominance signal from a composite video baseband signal | |
| JPH05244632A (en) | Motion adaptive image signal processor and method | |
| JPH0588597B2 (en) | ||
| JP2698637B2 (en) | Luminance signal / chrominance signal separation circuit | |
| EP0430049B1 (en) | Interpolation circuit of chrominance signal of a pal color television signal | |
| JPH0787590B2 (en) | Color signal processing circuit | |
| CA1229160A (en) | Field comb for luminance separation of ntsc signals |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |