EP0270259A2
Expired / Lapsed
EP
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Improvements relating to video signal processing systems
Assignee: Quantel Ltd
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Filing: 1987-11-09
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Granted: —
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Expires: 2007-11-09
Abstract
Abstract A video signal processing system is described in which a characteristic of individual picture points is provided to an accuracy of m binary bits but conveyed by n bits, where n is less than m. The value of a lower order bit of the n bit signal is switched to cause said binary value to represent, for any one picture point, either a value above or a value below the original value. The new values are distributed without order among the picture points with a probability dependent upon the value of the (m-n) lowest order bits of the desired value.
Inventors
- 👤 Robin Alexander Cawley
- 👤 Neil Roy Hinson
- 👤 Robert James Long
- 👤 Alan Lewis Stapleton
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 16:26
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/74; G; G06; G06F; G06F3/00; G06F3/01; G06F3/048; G06F3/0484; G06F3/04845; H04N1/00; H04N1/46
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
142 words
A video signal processing system in which a desired value for a characteristic of individual picture points is provided to an accuracy of m binary bits or better, and said value in the case of each of said picture points is conveyed by an n-bit binary signal, where (m-n) is an integer greater than 1, characterized in that the value of a lower order bit of said binary signal is switched to cause said binary signal to represent, for any one picture point, either a value above or a value below said desired value said one value or said other value being distributed without order among said picture points and the probability of said one value or said other value being present for any one picture point being dependent upon the value of the (m-n) lowest order bits of the desired value.
Claim 2
Dependent Claim
142 words
A video signal processing system in which a desired value for a characteristic of individual picture points is provided to an accuracy of m binary bits or better, and said value in the case of each of said picture points is conveyed by an n-bit binary signal, where (m-n) is an integer greater than 1, characterized in that the value of a lower order bit of said binary signal is switched to cause said binary signal to represent, for any one picture point, either a value above or a value below said desired value said one value or said other value being distributed without order among said picture points and the probability of said one value or said other value being present for any one picture point being dependent upon the value of the (m-n) lowest order bits of the desired value.
Claim 3
Dependent Claim
72 words
An effects generator for a graphics system comprising means for generating a line of signals for display representing a first colour, means for generating a line of signals for display representing a second colour, said lines being separated by a number of lines of display, characterizing by means for generating intervening lines of the signal, each line being generated as signals of said first and second colour interspersed randomly along the line.
Claim 4
Dependent Claim
72 words
An effects generator for a graphics system comprising means for generating a line of signals for display representing a first colour, means for generating a line of signals for display representing a second colour, said lines being separated by a number of lines of display, characterizing by means for generating intervening lines of the signal, each line being generated as signals of said first and second colour interspersed randomly along the line.
Claim 5
Dependent Claim
78 words
An effects generator for a graphics system comprising means for defining the colours of several lines of display separated by intervening lines, and means for generating each line of signals representing a defined colour as a mixture of two defined colours, characterized by means for generating signals for each of said intervening display lines as signals of a first defined colour and a proportion of a second defined colour according to the position of the respective display line.
Claim 6
Dependent Claim
78 words
An effects generator for a graphics system comprising means for defining the colours of several lines of display separated by intervening lines, and means for generating each line of signals representing a defined colour as a mixture of two defined colours, characterized by means for generating signals for each of said intervening display lines as signals of a first defined colour and a proportion of a second defined colour according to the position of the respective display line.
Claim 7
Dependent Claim
93 words
A graphics method for displaying a gradual change in a colour intensity or characteristic across a band of the image in which the image in said band is produced by interspersing two different signal elements representing two different values of said intensity or characteristic, characterised in that the proportion of the different signal elements in lines running along the band varies gradually with the displacement of the line across the band, but the distribution of the different signal elements in each line is random or sufficiently irregular to avoid or reduce dot patterning.
Claim 8
Dependent Claim
93 words
A graphics method for displaying a gradual change in a colour intensity or characteristic across a band of the image in which the image in said band is produced by interspersing two different signal elements representing two different values of said intensity or characteristic, characterised in that the proportion of the different signal elements in lines running along the band varies gradually with the displacement of the line across the band, but the distribution of the different signal elements in each line is random or sufficiently irregular to avoid or reduce dot patterning.
Claim 9
Dependent Claim
117 words
A video signal processing system comprising a first source of digital video signals, a second source of digital video signals, a source of factor signals K, first multiplier means for multiplying a signal from said first source by the factor signal K, second multiplier means for multiplying a signal from said second source by (1-K). said first and second multiplier means each producing a main product signal and a remainder signal, means for summing said remainder signals, means for utilising said summed remainder signals to select a random bit value, said selection being weighted according to the sum of the remainder, and means for summing said bit value and said main signals to produce an output signal.
Claim 10
Dependent Claim
117 words
A video signal processing system comprising a first source of digital video signals, a second source of digital video signals, a source of factor signals K, first multiplier means for multiplying a signal from said first source by the factor signal K, second multiplier means for multiplying a signal from said second source by (1-K). said first and second multiplier means each producing a main product signal and a remainder signal, means for summing said remainder signals, means for utilising said summed remainder signals to select a random bit value, said selection being weighted according to the sum of the remainder, and means for summing said bit value and said main signals to produce an output signal.
Claim 11
Dependent Claim
77 words
A video processing system according to claim 1 characterised in that for each picture point the value of the (m-n) lower order bits of the desired value is compared with the output of a random number generator, and the value of said lower order bit of said binary signal is switched depending on whether the value of the (m-n) lower order bits of the desired value is above or below the output of the random number generator.
Claim 12
Dependent Claim
49 words
A video signal processing system according to claim 1 or claim 6 characterised on that the value of the (n-m) lower order bits of the desired value for a particular picture point is derived from the position of the respective picture point relative to picture points of reference colour.
Claim 13
Dependent Claim
19 words
A graphic method according to claim 4 characterized in that said signal elements are ulilised to produce printing dots.
Claim 14
Dependent Claim
38 words
A system according to claim 1 characterised in that the probability of said one value or said other value of said binary signal being present for any one picture point is established by means of look up tables.
Claim 15
Dependent Claim
72 words
A system according to claim 9 in which a series of look up tables is provided one for each of a number of picture points, each look up table comprising a sequence of addresses, at the first of which a signal of value 1 may be found with low probability, at a second of which a signal of value 1 may be found with higher probability and so on for (m-n) addresses.
References Cited (Backward Citations)
No citation records indexed.
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