Colour conversion for a multy-primary display
AssigneeKoninklijke Philips N.V.
InventorsGerben Johan Hekstra, Oleg Belik
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Abstract
A multi-primary conversion method is disclosed for converting an input vector defining a color of an input pixel in a Linear color space into a drive vector having n components for driving “n” display primaries of a display color space. The drive vector comprises m sub-drive vectors for driving m groups of the display primaries.
Claims12
A multi-primary conversion method for converting an input vector (CIP) defining a color of an input pixel in a linear color space (X, Y, Z) into a drive vector (PD) of a display color space having n components for driving n display primaries (P1, . . . , Pn), the drive vector (PD) comprises m sub-drive vectors (PDi) for driving m groups of the display primaries (P1, . . . , Pn), the conversion method comprising:
- receiving the input vector (CIP) defining a color of an input pixel in a linear color spece at a processor input;
- determining by the processor in the linear color space (X, Y, Z) a position of the input vector (CIP) with respect to boundaries (CB) of each of three gamuts (FG, ELG, ELCG) being defined by transformed display primaries (CP1, . . . , CPn),
- wherein the three gamuts (FG, ELG, ELCG) indicate:
- a full gamut (FG) comprising all colors being reproducible with the m groups of the sub-drive vectors (PDi), an equal luminance sub-gamut (ELG) comprising all colors having equal luminance and being reproducible with each one of the m groups of the sub-drive vectors (PDi), and an equal luminance and equal chrominance sub-gamut (ELCG) comprising all colors being reproducible with each one of the m groups of sub-drive vectors (PDi) each having equal luminance and equal chrominance;
- selecting by the processor three boundary vectors (CB1, CB2, CB3) on the corresponding boundaries (CB) of the three gamuts (FG, ELG, ELCG) to enable the input vector (CIP) to be interpolated from the three boundary vectors (CB1, CB2, CB3),
- determining by the processor an interpolation factor (u) from the position of the input vector (CIP) with respect to the three boundary vectors (CB1, CB2, CB3), and
- interpolating by the processor in the display color space the drive vector (PD) representing the color of the input vector (CIP) in the display color space corresponding to the three boundary vectors (CB1, CB2, CB3) in the linear color space from the interpolation factor (u) and three boundary vectors (PB1, PB2, PB3).
A multi-primary conversion system for converting (CON) an input vector (CIP) defining a color of an input pixel in a linear color space (X, Y, Z) into a drive vector (PD) having n components for driving n display primaries (P1, . . . , Pn) of a display color space, the drive vector (PD) comprises m sub-drive vectors (PDi) for driving m groups of the display primaries (P1, . . . , Pn), the conversion system comprises a suitably programmed computer operative to:
- determine in the linear color space (X, Y, Z) a position of the input vector (CIP) with respect to boundaries (CB) of three gamuts (FG, ELG, ELCG) being defined by transformed display primaries (CP1, . . . , CPn), wherein the three gamuts (FG, ELG, ELCG) indicate:
- a full gamut (FG) comprising all colors being reproducible with the m groups of the sub-drive vectors (PDi), an equal luminance sub-gamut (ELG) comprising all colors having equal luminance and being reproducible with each one of the m groups of the sub-drive vectors (PDi), and an equal luminance and equal chrominance sub-gamut (ELCG) comprising all colors being reproducible with each one of the m groups of sub-drive vectors (PDi) each having equal luminance and equal chrominance;
- select three boundary vectors (CB1, CB2, CB3) on the boundaries (CB) of the three gamuts (FG, ELG, ELCG) to enable the input vector (CIP) to be interpolated from the three boundary vectors (CB1, CB2, CB3),
- determine an interpolation factor (u) from the position of the input vector (CIP) with respect to the three boundary vectors (CB1, CB2, CB3), and
- interpolate in the display color space the drive vector (PD) representing the color of the input vector (CIP) from the interpolation factor (u) and three boundary vectors (PB1, PB2, PB3) in the display color space corresponding to the three boundary vectors (CB1, CB2, CB3) in the linear color space.
Dependencies are inferred from the claim text.