| 摘要 |
Input device signals Rs, Gs, Bs generated by an image input terminal are converted to colorimetric values Rc, Gc, Bc. The colorimetric values processed by an image processing unit to generate address entries to a lookup table which stores a set of transform coefficients with which the Rc, Gc, Bc values may be processed to convert them to Cx, Mx, Yx, Kx colorant signals or any multi-dimensional output color space, which include but are not limited to CMYK or spectral data. Values which are not directly mapped from the table are determined using tetrahedral interpolation over a hexagonal lattice. The hexagonal lattice is formed by offsetting by a half unit every other row of one of its dimensions relative to another dimension. The offset provides closer packing of sample points that define more regular tetrahedrons to reduce relative interpolation errors. The packing also allows for easy lookup table access and simple tests to determine which tetrahedron contains a desired value.
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