A
color mapping method maps an input
image signal (IS) into an output
image signal (OS) for a display (DD) with display pixels (Pi) having sub-pixels (RP, GP, BP, YP) with primary colors (RW, GW, BW, YW) defining a display color
gamut (WG). A look-up table (1) comprises stored luminances (LU) of reflective spectra (RS) at different chromaticities (λO) within the display color
gamut (WG). The reflective spectra (RS) are spectra of reflective objects (RO) having a substantial maximum
reflectivity at the corresponding chromaticities (λO). The
color mapping method comprises a
gamut mapping (2), retrieving (3) a looked-up luminance (Y1), a factor determination (4), and adapting the mapped luminance (Ym; Y). The gamut mapping (2) maps the input
image signal (IS) having input pixel colors defined by an input luminance (Y) and an input
chromaticity (x, y) into a mapped image
signal (MS) having corresponding mapped pixel colors defined by a mapped luminance (Ym; Y) and a mapped
chromaticity (xm, ym). The input pixel colors lie within an input color gamut different than the display color gamut (WG). The looked-up luminance (Y1) is retrieved (3) by looking up the stored luminance (LU) in the look-up table (1) at the mapped
chromaticity (xm, ym). The factor (F) is determined (4) from a difference between the looked-up luminance (Y1) and the mapped luminance (Ym; Y). The mapped luminance (Ym; Y) is adapted (5) by using the factor (F; G) to obtain an output luminance (Ys) nearer to the looked-up luminance (Y1) than the mapped luminance (Ym). The image output
signal (OS) is defined by the mapped chromaticity (xm, ym) and the output luminance (Ys).