US5124688A
Expired / Lapsed
US
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Method and apparatus for converting digital YUV video signals to RGB video signals
Assignee: CERPLEX GROUP Inc
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Filing: 1990-05-07
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Granted: 1992-06-23
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Expires: 2010-05-07
Abstract
Abstract Method and apparatus process a composite video signal, converted it to component video signals which are processed digitally to produce reprogrammable digital RGB graphics signals. Specifically, a composite video signal is first digitized and then processed to convert digitized YUV component video signals into digitized RGB signals by means of a RAM-based table lookup technique optimized to the resolution of each of the component signals so as to minimize memory requirements and computation overhead. In a specific embodiment, a Y or luminance signal having a resolution of 6 bits is employed in connection with a V component signal having a resolution of 5 bits and a U component signal having a resolution of 3 bits without noticeable degradation of RGB color quality.
Inventors
- 👤 David A. Rumball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:46
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/28; G09G1/285; H; H04; H04N; H04N9/00; H04N9/64; H04N9/641
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
156 words
A method for converting digitized YUV component video signals to digitized RGB graphics signals for an RGB color graphics display of a computer, said method comprising the steps of: placing digitized transformation values for individual R, G and B component signals into a lookup table means based on a set of conversions from individual digitized Y, U, and V component signals, the R and B transformation values occupying a first segment of the lookup table means, and the G transformation values occupying a second segment of the lookup table means; selectively directing combinations of said digitized Y, U, and V component signals of selected limited resolution to address inputs of said lookup table means to effect reference to said R, G, and B transformation values; and sequentially reading out R component transformed values, B component transformed values and said G component transformed values to respective R, B and G latches in accordance with said address inputs.
Claim 2
Independent Claim
156 words
A method for converting digitized YUV component video signals to digitized RGB graphics signals for an RGB color graphics display of a computer, said method comprising the steps of: placing digitized transformation values for individual R, G and B component signals into a lookup table means based on a set of conversions from individual digitized Y, U, and V component signals, the R and B transformation values occupying a first segment of the lookup table means, and the G transformation values occupying a second segment of the lookup table means; selectively directing combinations of said digitized Y, U, and V component signals of selected limited resolution to address inputs of said lookup table means to effect reference to said R, G, and B transformation values; and sequentially reading out R component transformed values, B component transformed values and said G component transformed values to respective R, B and G latches in accordance with said address inputs.
Claim 3
Dependent Claim
52 words
The method according to claim 1 wherein said directing step comprises directing said V component signal at one half resolution of said Y component signal and said U component signal at one eighth resolution of said Y component signal together with said Y component signal during transformation of said G component signal.
Claim 4
Dependent Claim
38 words
The method according to claim 2 wherein said directing step comprises directing said V component signal at one half resolution of said Y component signal together with said Y component signal during transformation of said R component signal.
Claim 5
Dependent Claim
38 words
The method according to claim 3 wherein said directing step comprises directing said U component signal at one half resolution of said Y component signal together with said Y component signal during transformation of said B component signal.
Claim 6
Dependent Claim
38 words
The method according to claim 2 wherein said directing step comprises directing said U component signal at one half resolution of said Y component signal together with said Y component signal during transformation of said B component signal.
Claim 7
Independent Claim
181 words
An apparatus for converting digitized YUV component video signals to digitized RGB graphics signals for an RGB color graphics display of a computer, said apparatus comprising: table lookup means for storing digitized transformation values for individual R, G and B component signals based on a set of conversions from individual digitized Y, U, and V component signals, the R and B transformation values occupying a first segment of the lookup table means, and the G transformation values occupying a second segment of the lookup table means; means coupled to receive digitized Y, U and V component signals for selectively addressing address inputs of said table lookup means with combinations of said Y, U and V component signals, said addressing means providing selected limited resolution of said U and V component signals for said address inputs, in order to effect reference to said R, G, and B transformation values; and means for sequentially reading out R component transformed values, B component transformed values and said G component transformed values to respective R, B and G latches in accordance with said address inputs.
Claim 8
Independent Claim
181 words
An apparatus for converting digitized YUV component video signals to digitized RGB graphics signals for an RGB color graphics display of a computer, said apparatus comprising: table lookup means for storing digitized transformation values for individual R, G and B component signals based on a set of conversions from individual digitized Y, U, and V component signals, the R and B transformation values occupying a first segment of the lookup table means, and the G transformation values occupying a second segment of the lookup table means; means coupled to receive digitized Y, U and V component signals for selectively addressing address inputs of said table lookup means with combinations of said Y, U and V component signals, said addressing means providing selected limited resolution of said U and V component signals for said address inputs, in order to effect reference to said R, G, and B transformation values; and means for sequentially reading out R component transformed values, B component transformed values and said G component transformed values to respective R, B and G latches in accordance with said address inputs.
Claim 9
Independent Claim
220 words
An apparatus for converting digitized YUV component video signals to digitized RGB graphics signals for an RGB color graphics display of a computer, said apparatus comprising: table lookup means for storing digitized transformation values for individual R, G and B component signals based on a set of conversions from individual digitized Y, U, and V component signals, the R and B transformation values occupying a first segment of the lookup table means, and the G transformation values occupying a second segment of the lookup table means; means coupled to receive digitized Y, U and V component signals for selectively addressing address inputs of said table lookup means with combinations of said Y, U and V component signals, said addressing means providing selected limited resolution of said U and V component signals for said address inputs, in order to effect reference to said R, G, and B transformation values; and means for sequentially reading out R component transformed values, B component transformed values and said G component transformed values to respective R, B and G latches in accordance with said address inputs, wherein said addressing means comprises a multiplexer, said multiplexer having parallel inputs for said Y, U, and V component signals and parallel outputs for selected combinations of the most significant bits of said Y, U, and V component signals.
Claim 10
Independent Claim
220 words
An apparatus for converting digitized YUV component video signals to digitized RGB graphics signals for an RGB color graphics display of a computer, said apparatus comprising: table lookup means for storing digitized transformation values for individual R, G and B component signals based on a set of conversions from individual digitized Y, U, and V component signals, the R and B transformation values occupying a first segment of the lookup table means, and the G transformation values occupying a second segment of the lookup table means; means coupled to receive digitized Y, U and V component signals for selectively addressing address inputs of said table lookup means with combinations of said Y, U and V component signals, said addressing means providing selected limited resolution of said U and V component signals for said address inputs, in order to effect reference to said R, G, and B transformation values; and means for sequentially reading out R component transformed values, B component transformed values and said G component transformed values to respective R, B and G latches in accordance with said address inputs, wherein said addressing means comprises a multiplexer, said multiplexer having parallel inputs for said Y, U, and V component signals and parallel outputs for selected combinations of the most significant bits of said Y, U, and V component signals.
Claim 11
Dependent Claim
28 words
The apparatus according to claim 7 wherein said multiplexing means further includes an output for one bit value for selecting between said first segment and said second segment.
Claim 12
Dependent Claim
38 words
The apparatus according to claim 7 further including means coupled to said addressing means and to said multiplexing means for writing said digitized transformation values for individual R, G and B component signals to said table lookup means.
Claim 13
Dependent Claim
58 words
The apparatus according to claim 9 wherein multiplexing means comprises means for directing said V component signal at one half resolution of said Y component signal and said U component signal at one eighth resolution of said Y component signal together with said Y component signal to said table lookup means during transformation of said G component signal.
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| 3.5 Years (Year 4) | 1995-06-23 | 1995-12-23 | 1996-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-23 | 1999-12-23 | 2000-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-23 | 2003-12-23 | 2004-06-23 | $7700.00 | Window Closed / Lapsed |