Color gamut boundary information generating device, color gamut boundary information generating method, and computer readable medium

A color gamut boundary information generating method comprising:

• a processor configured to perforin the steps of:
• receiving a plurality of pieces of coordinate information indicating a plurality of points in a color space that is independent of an output device, respectively;
• performing a tetrahedralization process, with the plurality of points in the color space specified by the received plurality of pieces of coordinate information serving as vertexes;
• generating boundary information, which is a set of outermost triangular faces forming a convex hull among triangular faces obtained through the tetrahedralization process;
• and
• selecting one of the triangular faces included in the generated boundary information, the selected triangular face serving as a target face, regarding a tetrahedron including the target face as a target tetrahedron, determining whether or not the target tetrahedron satisfies a predetermined condition, and, if the target tetrahedron does not satisfy the predetermined condition, selecting the triangular faces included in the target tetrahedron except the target face, eliminating the target face from the boundary information, and adding the selected triangular faces to the boundary information, thereby correcting the boundary information;
• wherein the predetermined condition used for determination includes at least one of the following conditions:
• (i) in the triangular faces included in the target tetrahedron, except the target face, angles defining a vertex that is not included in the target face among the vertexes of the target tetrahedron satisfy a predetermined angle condition,
• (ii) area ratios of the triangular faces included in the target tetrahedron satisfy a predetermined area ratio condition, and
• (iii) signs of inner products of normal vectors of the triangular faces included in the target tetrahedron satisfy a predetermined sign condition.

A non-transitory computer readable medium storing a program causing a computer to execute a process, the process comprising:

• receiving a plurality of pieces of coordinate information indicating a plurality of points in a color space that is independent of an output device, respectively;
• performing a tetrahedralization process, with the plurality of points in the color space specified by the received plurality of pieces of coordinate information serving as vertexes;
• generating boundary information, which is a set of outermost triangular faces forming a convex hull among triangular faces obtained through the tetrahedralization process;
• and
• selecting one of the triangular faces included in the generated boundary information, the selected triangular face serving as a target face, regarding a tetrahedron including the target face as a target tetrahedron, determining whether or not the target tetrahedron satisfies a predetermined condition, and, if the target tetrahedron does not satisfy the predetermined condition, selecting the triangular faces included in the target tetrahedron except the target face, eliminating the target face from the boundary information, and adding the selected triangular faces to the boundary information, thereby correcting the boundary information;
• wherein the predetermined condition used for determination includes at least one of the following conditions:
• (i) in the triangular faces included in the target tetrahedron, except the target face, angles defining a vertex that is not included in the target face among the vertexes of the target tetrahedron satisfy a predetermined angle condition,
• (ii) area ratios of the triangular faces included in the target tetrahedron satisfy a predetermined area ratio condition, and
• (iii) signs of inner products of normal vectors of the triangular faces included in the target tetrahedron satisfy a predetermined sign condition.