Signal processing apparatus image processing apparatus and their methods
AssigneeCanon Kabushiki Kaisha
InventorHirochika Matsuoka
Life of this patent
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Abstract
A color gamut that has been mapped from a monitor gamut into a printer gamut by gamut mapping is narrower than the printer gamut. Hence, an image to be output, which is corrected by gamut mapping, has low contrast and poor vividness. Hence, a gamut enlargement correction unit (1208) maps an intermediate mapped gamut into the printer gamut with reference to the intermediate mapped gamut obtained by mapping the monitor gamut, and the printer gamut, thus obtaining a mapped gamut for gamut mapping.
Claims19
An image processing method for mapping an input color of an input color gamut to an output color of an output color gamut, said method comprising the steps of:
- inputting an input color signal of the input color gamut, which includes a signal indicating brightness and a signal indicating tincture;
- and
- mapping the signal indicating brightness and the signal indicating tincture on the basis of the input and output color gamuts,
- wherein the mapping maps the signal indicating brightness using a mapping condition which is computed in accordance with highlight portions of the input and output color gamuts, and increases a degree of mapping of the highlight portion compared to middle lightness, and
- wherein the mapping condition is given by a piecewise function.
An image processing method for mapping an input color of an input color gamut to an output color of an output color gamut, said method comprising the steps of:
- inputting an input color signal of the input color gamut, which includes a signal indicating brightness and a signal indicating tincture;
- and
- mapping the signal indicating brightness and the signal indicating tincture on the basis of the input and output color gamuts,
- wherein the mapping maps the signal indicating tincture using a mapping condition which is computed in accordance with high-saturation portions of the input and output color gamuts at a predetermined hue, and increases a degree of mapping of the high-saturation portion compared to a low-saturation portion, and
- wherein the mapping condition is given by a piecewise function.
An image processing method for mapping an input color of an input color gamut to an output color of an output color gamut, said method comprising the steps of:
- executing a first mapping process for the input color gamut in accordance with the input and output color gamuts;
- and
- executing a second mapping process for a mapped color gamut obtained by the first mapping process in accordance with the mapped color gamut and output color gamut,
- wherein the first mapping process is a process for compressing a color gamut, and the second mapping process is a process for expanding the color gamut.
A computer program product comprising a computer readable medium comprising computer program code, for an image processing method for mapping an input color of an input color gamut to an output color of an output color gamut, said method comprising the steps of:
- inputting an input color signal of the input color gamut, which includes a signal indicating brightness and a signal indicating tincture;
- and
- mapping the signal indicating brightness and the signal indicating tincture on the basis of the input and output color gamuts,
- wherein the mapping maps the signal indicating brightness using a mapping condition which is computed in accordance with highlight portions of the input and output color gamuts, and increases a degree of mapping of the highlight portion compared to middle lightness, and
- wherein the mapping condition is given by a piecewise function.
A computer program product comprising a computer readable medium comprising computer program code, for an image processing method for mapping an input color of an input color gamut to an output color of an output color gamut, said method comprising the steps of:
- inputting an input color signal of the input color gamut, which includes a signal indicating brightness and a signal indicating tincture;
- and
- mapping the signal indicating brightness and the signal indicating tincture on the basis of the input and output color gamuts,
- wherein the mapping maps the signal indicating tincture using a mapping condition which is computed in accordance with high-saturation portions of the input and output color gamuts at a predetermined hue, and increases a degree of mapping of the high-saturation portion compared to a low-saturation portion, and
- wherein the mapping condition is given by a piecewise function.
A computer program product comprising a computer readable medium comprising computer program code, for an image processing method for mapping an input color of an input color gamut to an output color of an output color gamut, said method comprising the steps of:
- executing a first mapping process for the input color gamut in accordance with the input and output color gamuts;
- and
- executing a second mapping process for a mapped color gamut obtained by the first mapping process in accordance with the mapped color gamut and output color gamut,
- wherein the first mapping process is a process for compressing a color gamut, and the second mapping process is a process for expanding the color gamut.
An image processing apparatus for mapping an input color of an input color gamut to an output color of an output color gamut, comprising:
- inputting section, arranged to input an input color signal of the input color gamut, which includes a signal indicating brightness and a signal indicating tincture;
- and
- a mapping section, adapted to map the signal indicating brightness and the signal indicating tincture on the basis of the input and output color gamuts,
- wherein the mapping maps the signal indicating brightness using a mapping condition which is computed in accordance with highlight portions of the input and output color gamuts, and increases a degree of mapping of the highlight portion compared to middle lightness, and
- wherein the mapping condition is given by a piecewise function.
An image processing apparatus for mapping an input color of an input color gamut to an output color of an output color gamut, comprising:
- an inputting section, arranged to input an input color signal of the input color gamut, which includes a signal indicating brightness and a signal indicating tincture;
- and
- mapping section, adapted to map the signal indicating brightness and the signal indicating tincture on the basis of the input and output color gamuts,
- wherein the mapping maps the signal indicating tincture using a mapping condition which is computed in accordance with high-saturation portions of the input and output color gamuts at a predetermined hue, and increases a degree of mapping of the high-saturation portion compared to a low-saturation portion, and
- wherein the mapping condition is given by a piecewise function.
An image processing apparatus for mapping an input color of an input color gamut to an output color of an output color gamut, comprising:
- a first mapping section, adapted to execute a first mapping process for the input color gamut in accordance with the input and output color gamuts;
- and
- a second mapping section, adapted to execute a second mapping process for a mapped color gamut obtained by the first mapping process in accordance with the mapped color gamut and output color gamut,
- wherein the first mapping process is a process for compressing a color gamut, and the second mapping process is a process for expanding the color gamut.
Dependencies are inferred from the claim text.