EP0142975A2
Expired / Lapsed
EP
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Apparatus and method for reproducing an original colour image
Assignee: Toshiba Corp
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Filing: 1984-11-13
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Granted: —
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Expires: 2004-11-13
Abstract
Abstract For the reproduction of a colour image, an input unit (1) scans the image and derives a plurality of colour signals (2) corresponding to each picture element of the original image. The colour signals are converted (7) into a set of luminance and subtracted colour signals (8, 9a, 9b). The set of luminance and subtracted colour signals are then converted into a set of ink concentration signals (12) for the colour printer (13) using a conversion table (11). The conversion table (11) stores sets of ink concentration signals which are within a reproducible range of colours by the colour printer (13). Where the set of luminance and subtracted colour signals do not correspond to a colour reproducible by the printer, a set of ink concentration signals which correspond to a reproducible colour are provided by the conversion table (11).
Inventors
- 👤 Naofumi C/O Patent Div. Toshiba Corp. Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 20:58
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6058
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
162 words
Apparatus for reproducing an original colour image comprising input means (1, 3) for deriving a plurality of colour signals corresponding to each picture element of the original colour image; separating means (7) coupled to the input means (1, 3) for converting the colour signals into a set of corresponding luminance and subtracted colour signals; conversion means (11) coupled to the separating means (7) for converting the set of luminance and subtracted colour signals into a set of corresponding driving signals; and output means (13) connected to the conversion means (11) and operable over a predetermined range of colours for reproducing the original image in accordance with the set of driving signals: characterised in that the conversion means (11) are so arranged that, when the set of luminance and subtracted colour signals does not correspond to a colour within the predetermined range of colours, that set is converted to an alternative set of driving signals which correspond to a colour within the range.
Claim 2
Dependent Claim
162 words
Apparatus for reproducing an original colour image comprising input means (1, 3) for deriving a plurality of colour signals corresponding to each picture element of the original colour image; separating means (7) coupled to the input means (1, 3) for converting the colour signals into a set of corresponding luminance and subtracted colour signals; conversion means (11) coupled to the separating means (7) for converting the set of luminance and subtracted colour signals into a set of corresponding driving signals; and output means (13) connected to the conversion means (11) and operable over a predetermined range of colours for reproducing the original image in accordance with the set of driving signals: characterised in that the conversion means (11) are so arranged that, when the set of luminance and subtracted colour signals does not correspond to a colour within the predetermined range of colours, that set is converted to an alternative set of driving signals which correspond to a colour within the range.
Claim 3
Dependent Claim
30 words
Apparatus according to claim 1, wherein the alternative set of driving signals corresponds to the colour closest to the colour corresponding to the set of luminance and subtracted colour signals.
Claim 4
Dependent Claim
35 words
Apparatus according to claim 1 or claim 2, wherein the conversion means includes memory means for storing predetermined driving signals for luminance and subtracted colour signals which correspond to colours within said range of colours.
Claim 5
Independent Claim
123 words
A method for reproducing an original colour image, the method comprising the steps of: deriving a plurality of colour signals corresponding to each picture element of the original colour image; converting the colour signals into a set of corresponding luminance and subtracted colour signals; converting the set of luminance and subtracted colour signals into a set of corresponding driving signals; and reproducing the original colour image in accordance with the set of driving signals; characterised in that, when the set of luminance and subtracted colour signals does not correspond to a colour within a reproducible range of colours, the set of luminance and subtracted colour signals is converted to an alternative set of driving signals which correspond to a colour within that range.
Claim 6
Independent Claim
123 words
A method for reproducing an original colour image, the method comprising the steps of: deriving a plurality of colour signals corresponding to each picture element of the original colour image; converting the colour signals into a set of corresponding luminance and subtracted colour signals; converting the set of luminance and subtracted colour signals into a set of corresponding driving signals; and reproducing the original colour image in accordance with the set of driving signals; characterised in that, when the set of luminance and subtracted colour signals does not correspond to a colour within a reproducible range of colours, the set of luminance and subtracted colour signals is converted to an alternative set of driving signals which correspond to a colour within that range.
References Cited (Backward Citations)
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