Multi-dimensional edge interpolation

A computer-implemented method for using a color table to determine an output color in a destination color space based on an input color in a source color space, the color table defining a mapping from the source color space representing colors in source color coordinates to a destination color space representing colors in destination color coordinates, the color table defining for each of a domain of source colors in the source color space a corresponding destination color in the destination color space, the method comprising:

• receiving an input color represented in the source color space;
• determining a cell of the color table that encloses the input color, each corner of the cell representing a source color and a corresponding destination color and one corner of the cell being the cell origin;
• determining a location of the input color within the cell in terms of cell coordinate values in a cell coordinate system having an origin coinciding with the cell origin, each coordinate value corresponding to a dimension of the source color space;
• setting the destination color of the cell origin to be an initial output color;
• selecting the highest cell coordinate value for the input color;
• obtaining the destination color at the corner of the cell that is opposite to the cell origin for the source color space dimension corresponding to the selected cell coordinate value;
• interpolating a contribution to the output color using the selected cell coordinate value and the destination colors at the origin and at the opposite corner;
• adding the interpolated contribution to the output color,
• determining a final output color by repeating the steps of selecting, obtaining, interpolating and adding, while using the corner opposite to the cell origin as a new cell origin and excluding processed cell coordinate values, at each step determining whether a cell coordinate value of zero has been reached and terminating when a cell coordinate value of zero has been reached.

A computer program product, tangibly stored on a computer-readable medium, for using a color table, the color table defining a mapping from a source color space representing colors in source color coordinates to a destination color space representing colors in destination color coordinates, the color table defining for each of a domain of source colors in the source color space a corresponding destination color in the destination color space, comprising instructions operable to cause a programmable processor to:

• receive an input color represented in the source color space;
• determine a location of the input color in a cell of the color table in terms of cell coordinate values in a cell coordinate system, each corner of the cell representing a source color and a corresponding destination color, each coordinate value corresponding to a dimension of the source color space;
• determine an order of the cell coordinate values;
• determine a processing order of the dimensions of the source color space according to the order of the cell coordinate values;
• and
• use the cell coordinate values in the processing order to calculate an output color represented in the destination color space, making no more interpolation calculations than the number of source color space dimensions multiplied by the number of destination color space dimensions, including detecting when adjacent source color coordinates in the processing order have identical values and in response performing a single interpolation calculation for all the detected adjacent source color coordinates to calculate a single contribution to the calculated output color.

A computer program product, tangibly stored on a computer-readable medium, for using a color table to determine an output color in a destination color space based on an input color in a source color space, the color table defining a mapping from the source color space representing colors in source color coordinates to a destination color space representing colors in destination color coordinates, the color table defining for each of a domain of source colors in the source color space a corresponding destination color in the destination color space, comprising instructions operable to cause a programmable processor to:

• receive an input color represented in the source color space;
• determine a cell of the color table that encloses the input color, each corner of the cell representing a source color and a corresponding destination color and one corner of the cell being the cell origin;
• determine a location of the input color within the cell in terms of cell coordinate values in a cell coordinate system having an origin coinciding with the cell origin, each coordinate value corresponding to a dimension of the source color space;
• set the destination color of the cell origin to be an initial output color,
• select the highest cell coordinate value for the input color;
• obtain the destination color at the corner of the cell that is opposite to the cell origin for the source color space dimension corresponding to the selected cell coordinate value;
• interpolate a contribution to the output color using the selected cell coordinate value and the destination colors at the origin and at the opposite corner;
• add the interpolated contribution to the output color;
• determine a final output color by repeating the steps of select, obtain, interpolate and add, while using the corner opposite to the cell origin as a new cell origin and excluding processed cell coordinate values, at each step determining whether a cell coordinate value of zero has been reached and terminating when a cell coordinate value of zero has been reached.