Method of creating a gamut boundary descriptor preserving the discontinuities of an actual gamut surface

Method of creating a gamut boundary descriptor of an actual gamut boundary of all colors that can be output by a color device, comprising the-steps of:

• using an intermediate color device executing:
• in a transformation color space, selecting gamut boundary colors sampling a surface of said actual gamut boundary,
• using said selected gamut boundary colors, generating a network of elementary polygons representing said actual gamut boundary, each selected gamut boundary color belonging to an elementary polygon,
• generating an initial gamut boundary descriptor from said network of elementary polygons,
• identifying vertices and edges of elementary polygons that belong to a line or a point of discontinuity of said actual gamut boundary,
• smoothing said initial gamut boundary descriptor into a final gamut boundary descriptor that is closer to said actual gamut boundary than said initial gamut boundary descriptor,
• wherein said smoothing:
• does not change position of the identified vertices and of the identified edges,
• does not change the discontinuities of curvature of said actual gamut boundary at said identified vertices and at said identified edges;
• and
• using the fmal gamut boundary descriptor to output an image by the color device.