EP0469892A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Filter device for decimation and interpolation of chrominance components of a video signal
Assignee: Panasonic Holdings Corp
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Filing: 1991-07-31
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Granted: —
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Expires: 2011-07-31
Abstract
Abstract For decimation or interpolation of pixel data of the chrominance component of a video signal, a decimation or interpolation filter is selectively used. In general, the chrominance signal (1) and the luminance signal (2) are closely related to each other and their edge pattern data coincide with each other when reproduced on a picture screen. A filter device (7) for decimation or interpolation of the chrominance signal is arranged to perform a number of filtering actions depending on the presence or absence and location of edge pattern data. The present, absence, and location of the edge pattern data is detected using the luminance signal (2) which is neither decimated nor interpolated.
Inventors
- 👤 Hideki Otaka
- 👤 Masakazu Nishino
- 👤 Tatsuro Juri
- 👤 Shinya Kadono
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:16
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/646; H04N9/77
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
95 words
A chroma signal decimation filter device comprising: a correlation detector for detecting a correlation between pixel data of a luminance signal which correspond in the positional assignment on a picture screen to those of a chominance signal to be decimated; a filter unit for performing at least two different filterings using a target pixel data and its adjacent pixel data of the chrominance signal; and a filter selector for determining the filtering procedure of the filter unit in accordance with the correlation between the pixel data of the luminance signal detected by the correlation detector.
Claim 2
Dependent Claim
56 words
A chroma signal decimation filter device according to Claim 1, wherein the filter unit is capable of changing filter coefficients and the filter selector is adapted for determining the values of the filter coefficients of the filter unit in accordance with the correlation between the pixel data of the luminance signal detected by the correlation detector.
Claim 3
Dependent Claim
101 words
A chroma signal decimation filter device according to Claim 2, wherein if the target pixel data to be decimated and its two adjacent, front and rear, data of the chrominance signal are C i , C i-1 , and C i+1 respectively and two of the correlation values given by the correlation detector are p and q, the output C i ' of the filter unit is obtained from: C i ' = p C i + 1 / 2 C i + q C i + 1 ---- ( 1 ) ( p + q = 1 / 2 )
Claim 4
Dependent Claim
151 words
A chroma signal decimation filter device according to Claim 3, wherein if the three pixel data of the luminance signal corresponding to C i , C i-1 , and C i+1 of the chrominance signal in the positional assignment are Y i , Y i-1 , and Y i+1 and a constant is a, p and q are respectively calculated with the filter unit from: p = 1 2 x | Y i - Y i + 1 | + a | Y i - 1 - Y i | + a + | Y i - Y i + 1 | + a ---- ( 2 ) q = 1 2 x | Y i - 1 - Y i | + a | Y i - 1 - Y i | + a + | Y i - Y i + 1 | + a ---- ( 3 )
Claim 5
Dependent Claim
65 words
A chroma signal decimation filter device according to Claim 1, wherein the correlation detector is adapted for comparing the pixel data of the luminance signal corresponding to the target pixel data of the chrominance signal with at least two pixel data produced by interpolation of the luminance signal by two different interpolation techniques and transmitting a pair of resultant comparison values to the filter selector.
Claim 6
Dependent Claim
68 words
A chroma signal decimation filter device according to Claim 1, wherein the correlation detector is adapted for comparing the pixel data of the luminance signal, which corresponds to the target pixel data of the chrominance signal in the positional assignment, and its adjacent pixel data with at least two pixel data produced by interpolation of the luminance signal respectively and transmitting resultant comparison values to the filter selector
Claim 7
Dependent Claim
53 words
A chroma signal decimation filter device according to Claim 1, wherein the correlation detector is adapted for detecting the correlation between two data of a luminance signal which has been band limited by a lowpass filter and the filter unit is adapted for decimation of horizontally arranged pixel data of the chrominance signal.
Claim 8
Dependent Claim
27 words
A chroma signal decimation filter device according to Claim 1, wherein the filter unit is adapted for decimation of vertically arranged pixel data of the chrominance signal.
Claim 9
Dependent Claim
106 words
A chroma signal interpolation filter device comprising: a correlation detector for detecting a correlation between pixel data of a luminance signal which correspond in the positional assignment on a picture screen to those of a chrominance signal, one of which is a target pixel data to be interpolated and has a value of 0; a filter unit for performing a filtering action using some other chrominance pixel data than the target pixel data to be interpolated; and a filter selector for determining filter coefficients of the filter unit in accordance with the correlation between the pixel data of the luminance signal detected by the correlation detector.
Claim 10
Dependent Claim
98 words
A chroma signal interpolation filter device according to Claim 9, wherein if the target pixel data to be interpolated and its two adjacent, front and rear, data of the chrominance signal are C i , C i-1 , and C i+1 respectively and two of the correlation values given by the correlation detector are p and q, the output C i ' of the filter unit is obtained from: C i ' = p C i - 1 + C i + q C i + 1 ---- ( 4 ) ( p + q = 1 )
Claim 11
Dependent Claim
145 words
A chroma signal interpolation filter device according to Claim 10, wherein if the three pixel data of the luminance signal corresponding to C i , C i-1 , and C i+1 of the chrominance signal in the positional assignment are Y i , Y i- ₁, and Y i+1 and a constant is b, p and q are respectively calculated with the filter unit from: p = | Y i - Y i + 1 | + b | Y i - 1 - Y i | + b + | Y i - Y i + 1 | + b ---- ( 5 ) q = | Y i - 1 - Y i | + b | Y i - 1 - Y i | + b + | Y i - Y i + 1 | + b ---- ( 6 )
Claim 12
Dependent Claim
53 words
A chroma signal interpolation filter device according to Claim 9, wherein the correlation detector is adapted for detecting the correlation between two data of a luminance signal which has been band limited by a lowpass filter and the filter unit is adapted for interpolation of horizontally arranged pixel data of the chrominance signal.
Claim 13
Dependent Claim
27 words
A chroma signal interpolation filter device according to Claim 9, wherein the filter unit is adapted for interpolation of vertically arranged pixel data of the chrominance signal.
Claim 14
Dependent Claim
120 words
A chroma signal interpolation filter device comprising: a correlation detector for detecting a correlation between pixel data of a luminance signal which correspond to those of a chrominance signal, one of which is a target pixel data to be interpolated, in the positional assignment on a picture screen; a filter unit for performing at least two different filtering actions on the target pixel data to be interpolated using some other chrominance pixel data than the target pixel data while no filtering the other pixel data of the chrominance signal; and a filter selector for determining the filtering procedure of the filter unit in accordance with the correlation between the pixel data of the luminance signal detected by the correlation detector.
Claim 15
Dependent Claim
68 words
A chroma signal interpolation filter device according to Claim 14, wherein the correlation detector is adapted for comparing the pixel data of the luminance signal corresponding to the target pixel data of the chrominance signal to be interpolated with at least two pixel data produced by interpolation of the luminance signal by two different interpolation techniques and transmitting a pair of resultant comparison values to the filter selector.
Claim 16
Dependent Claim
29 words
A chroma signal interpolation filter device according to Claim 15, wherein the interpolation of the luminance signal is carried out in the respect of three-front, rear, and average-different data.
Claim 17
Dependent Claim
51 words
A chroma signal interpolation filter device according to Claim 14, wherein the filter unit comprises three discrete filters for interpolation of the chrominance signal having a 1/2 decimated form of checkerboard pattern; a filter for vertical interpolation, a filter for horizontal interpolation, and a filter for two-dimensional, vertical and horizontal, interpolation.
References Cited (Backward Citations)
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