* The advantage of this class is that it provides color transform matrices and * lookup tables that Java or native methods can use directly to optimize color * conversion in some cases. *
* To transform from a device profile color space to the CIEXYZ Profile * Connection Space, each device color component is first linearized by a lookup * through the corresponding tone reproduction curve (TRC). The resulting linear * RGB components are converted to the CIEXYZ PCS using a a 3x3 matrix * constructed from the RGB colorants. *
* * linearR = redTRC[deviceR] * * linearG = greenTRC[deviceG] * * linearB = blueTRC[deviceB] * * _ _ _ _ _ _ * [ PCSX ] [ redColorantX greenColorantX blueColorantX ] [ linearR ] * [ ] [ ] [ ] * [ PCSY ] = [ redColorantY greenColorantY blueColorantY ] [ linearG ] * [ ] [ ] [ ] * [_ PCSZ _] [_ redColorantZ greenColorantZ blueColorantZ _] [_ linearB _] * ** The inverse transform is performed by converting PCS XYZ components to linear * RGB components through the inverse of the above 3x3 matrix, and then * converting linear RGB to device RGB through inverses of the TRCs. */ public class ICC_ProfileRGB extends ICC_Profile { static final long serialVersionUID = 8505067385152579334L; /** * Used to get a gamma value or TRC for the red component. */ public static final int REDCOMPONENT = 0; /** * Used to get a gamma value or TRC for the green component. */ public static final int GREENCOMPONENT = 1; /** * Used to get a gamma value or TRC for the blue component. */ public static final int BLUECOMPONENT = 2; /** * Constructs an new {@code ICC_ProfileRGB} from a CMM ID. * * @param p the CMM ID for the profile. */ ICC_ProfileRGB(Profile p) { super(p); } /** * Constructs a new {@code ICC_ProfileRGB} from a * {@code ProfileDeferralInfo} object. * * @param pdi */ ICC_ProfileRGB(ProfileDeferralInfo pdi) { super(pdi); } /** * Returns an array that contains the components of the profile's * {@code mediaWhitePointTag}. * * @return a 3-element {@code float} array containing the x, y, and z * components of the profile's {@code mediaWhitePointTag} */ public float[] getMediaWhitePoint() { return super.getMediaWhitePoint(); } /** * Returns a 3x3 {@code float} matrix constructed from the X, Y, and Z * components of the profile's {@code redColorantTag}, * {@code greenColorantTag}, and {@code blueColorantTag}. *
* This matrix can be used for color transforms in the forward direction of * the profile--from the profile color space to the CIEXYZ PCS. * * @return a 3x3 {@code float} array that contains the x, y, and z * components of the profile's {@code redColorantTag}, * {@code greenColorantTag}, and {@code blueColorantTag} */ public float[][] getMatrix() { float[][] theMatrix = new float[3][3]; float[] tmpMatrix; tmpMatrix = getXYZTag(ICC_Profile.icSigRedColorantTag); theMatrix[0][0] = tmpMatrix[0]; theMatrix[1][0] = tmpMatrix[1]; theMatrix[2][0] = tmpMatrix[2]; tmpMatrix = getXYZTag(ICC_Profile.icSigGreenColorantTag); theMatrix[0][1] = tmpMatrix[0]; theMatrix[1][1] = tmpMatrix[1]; theMatrix[2][1] = tmpMatrix[2]; tmpMatrix = getXYZTag(ICC_Profile.icSigBlueColorantTag); theMatrix[0][2] = tmpMatrix[0]; theMatrix[1][2] = tmpMatrix[1]; theMatrix[2][2] = tmpMatrix[2]; return theMatrix; } /** * Returns a gamma value representing the tone reproduction curve (TRC) for * a particular component. The component parameter must be one of * {@code REDCOMPONENT}, {@code GREENCOMPONENT}, or {@code BLUECOMPONENT}. *
* If the profile represents the TRC for the corresponding component as a * table rather than a single gamma value, an exception is thrown. In this * case the actual table can be obtained through the {@link #getTRC(int)} * method. When using a gamma value, the linear component (R, G, or B) is * computed as follows: *
*
* gamma
* linearComponent = deviceComponent
*
*
*
* @param component the {@code ICC_ProfileRGB} constant that represents the
* component whose TRC you want to retrieve
* @return the gamma value as a float
* @throws ProfileDataException if the profile does not specify the
* corresponding TRC as a single gamma value
*/
public float getGamma(int component) {
float theGamma;
int theSignature;
switch (component) {
case REDCOMPONENT:
theSignature = ICC_Profile.icSigRedTRCTag;
break;
case GREENCOMPONENT:
theSignature = ICC_Profile.icSigGreenTRCTag;
break;
case BLUECOMPONENT:
theSignature = ICC_Profile.icSigBlueTRCTag;
break;
default:
throw new IllegalArgumentException("Must be Red, Green, or Blue");
}
theGamma = super.getGamma(theSignature);
return theGamma;
}
/**
* Returns the TRC for a particular component as an array. Component must be
* {@code REDCOMPONENT}, {@code GREENCOMPONENT}, or {@code BLUECOMPONENT}.
* Otherwise the returned array represents a lookup table where the input
* component value is conceptually in the range [0.0, 1.0]. Value 0.0 maps
* to array index 0 and value 1.0 maps to array index {@code length-1}.
* Interpolation might be used to generate output values for input values
* that do not map exactly to an index in the array. Output values also map
* linearly to the range [0.0, 1.0]. Value 0.0 is represented by an array
* value of 0x0000 and value 1.0 by 0xFFFF. In other words, the values are
* really unsigned {@code short} values even though they are returned in a
* {@code short} array.
* * If the profile has specified the corresponding TRC as linear (gamma = * 1.0) or as a simple gamma value, this method throws an exception. In this * case, the {@link #getGamma(int)} method should be used to get the gamma * value. * * @param component the {@code ICC_ProfileRGB} constant that represents the * component whose TRC you want to retrieve: {@code REDCOMPONENT}, * {@code GREENCOMPONENT}, or {@code BLUECOMPONENT} * @return a short array representing the TRC * @throws ProfileDataException if the profile does not specify the * corresponding TRC as a table */ public short[] getTRC(int component) { short[] theTRC; int theSignature; switch (component) { case REDCOMPONENT: theSignature = ICC_Profile.icSigRedTRCTag; break; case GREENCOMPONENT: theSignature = ICC_Profile.icSigGreenTRCTag; break; case BLUECOMPONENT: theSignature = ICC_Profile.icSigBlueTRCTag; break; default: throw new IllegalArgumentException("Must be Red, Green, or Blue"); } theTRC = super.getTRC(theSignature); return theTRC; } }