Color characterization of projectors
First Claim
1. A method for transforming a device-dependent color value in a device-dependent color space of a display device to a perceptually linear color value in a perceptually linear color space, the method comprising:
- a first determining step of determining a first color value in a perceptually linear color space, by applying a matrix model to the device-dependent color value to obtain an XYZ color value in an XYZ color space, the matrix model applying a tone curve correction and a tristimulus matrix to the device-dependent color value, and by converting the XYZ color value into the first color value using a color space converter;
a second determining step of determining a difference value in the perceptually linear color space, wherein the difference value is determined by applying a difference model to the device-dependent color value, and wherein the difference model models deviation of the matrix model from actual measurements of the display device; and
an adding step of adding the difference value and the first color value to obtain the perceptually linear color value.
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Abstract
The present invention transforms a device-dependent color value in a device-dependent color space of a display device to a device-independent color value in a device-independent color space. A first color value is determined in a perceptually linear color space by applying a matrix model to the device-dependent color value, the matrix model applying a tone curve correction and a tristimulus matrix to the device-dependent color value. A difference value is then determined in the perceptually linear color space, wherein the difference value is determined by applying a difference model to the device-dependent color value, and wherein the difference model models deviation of the matrix model from actual measurements of the display device. Next, the difference value and the first color value are added and the sum is transformed to the device-independent color space. Because the first value based on the matrix model is added to a difference value which accounts for deviation of the matrix model, the present invention can account for the channel interdependency prevalent in DLP display devices.
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Citations
11 Claims
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1. A method for transforming a device-dependent color value in a device-dependent color space of a display device to a perceptually linear color value in a perceptually linear color space, the method comprising:
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a first determining step of determining a first color value in a perceptually linear color space, by applying a matrix model to the device-dependent color value to obtain an XYZ color value in an XYZ color space, the matrix model applying a tone curve correction and a tristimulus matrix to the device-dependent color value, and by converting the XYZ color value into the first color value using a color space converter; a second determining step of determining a difference value in the perceptually linear color space, wherein the difference value is determined by applying a difference model to the device-dependent color value, and wherein the difference model models deviation of the matrix model from actual measurements of the display device; and an adding step of adding the difference value and the first color value to obtain the perceptually linear color value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification