* Typically, a Color or ColorModel would be associated with an ICC * Profile which is either an input, display, or output profile (see * the ICC specification). There are other types of ICC Profiles, e.g. * abstract profiles, device link profiles, and named color profiles, * which do not contain information appropriate for representing the color * space of a color, image, or device (see ICC_Profile). * Attempting to create an ICC_ColorSpace object from an inappropriate ICC * Profile is an error. *
* ICC Profiles represent transformations from the color space of * the profile (e.g. a monitor) to a Profile Connection Space (PCS). * Profiles of interest for tagging images or colors have a * PCS which is one of the device independent * spaces (one CIEXYZ space and two CIELab spaces) defined in the * ICC Profile Format Specification. Most profiles of interest * either have invertible transformations or explicitly specify * transformations going both directions. Should an ICC_ColorSpace * object be used in a way requiring a conversion from PCS to * the profile's native space and there is inadequate data to * correctly perform the conversion, the ICC_ColorSpace object will * produce output in the specified type of color space (e.g. TYPE_RGB, * TYPE_CMYK, etc.), but the specific color values of the output data * will be undefined. *
* The details of this class are not important for simple applets, * which draw in a default color space or manipulate and display * imported images with a known color space. At most, such applets * would need to get one of the default color spaces via * ColorSpace.getInstance(). * @see ColorSpace * @see ICC_Profile */ public class ICC_ColorSpace extends ColorSpace { static final long serialVersionUID = 3455889114070431483L; private ICC_Profile thisProfile; private float[] minVal; private float[] maxVal; private float[] diffMinMax; private float[] invDiffMinMax; private boolean needScaleInit = true; // {to,from}{RGB,CIEXYZ} methods create and cache these when needed private transient ColorTransform this2srgb; private transient ColorTransform srgb2this; private transient ColorTransform this2xyz; private transient ColorTransform xyz2this; /** * Constructs a new ICC_ColorSpace from an ICC_Profile object. * @param profile the specified ICC_Profile object * @exception IllegalArgumentException if profile is inappropriate for * representing a ColorSpace. */ public ICC_ColorSpace (ICC_Profile profile) { super (profile.getColorSpaceType(), profile.getNumComponents()); int profileClass = profile.getProfileClass(); /* REMIND - is NAMEDCOLOR OK? */ if ((profileClass != ICC_Profile.CLASS_INPUT) && (profileClass != ICC_Profile.CLASS_DISPLAY) && (profileClass != ICC_Profile.CLASS_OUTPUT) && (profileClass != ICC_Profile.CLASS_COLORSPACECONVERSION) && (profileClass != ICC_Profile.CLASS_NAMEDCOLOR) && (profileClass != ICC_Profile.CLASS_ABSTRACT)) { throw new IllegalArgumentException("Invalid profile type"); } thisProfile = profile; setMinMax(); } /** * Returns the ICC_Profile for this ICC_ColorSpace. * @return the ICC_Profile for this ICC_ColorSpace. */ public ICC_Profile getProfile() { return thisProfile; } /** * Transforms a color value assumed to be in this ColorSpace * into a value in the default CS_sRGB color space. *
* This method transforms color values using algorithms designed
* to produce the best perceptual match between input and output
* colors. In order to do colorimetric conversion of color values,
* you should use the toCIEXYZ
* method of this color space to first convert from the input
* color space to the CS_CIEXYZ color space, and then use the
* fromCIEXYZ method of the CS_sRGB color space to
* convert from CS_CIEXYZ to the output color space.
* See {@link #toCIEXYZ(float[]) toCIEXYZ} and
* {@link #fromCIEXYZ(float[]) fromCIEXYZ} for further information.
*
* @param colorvalue a float array with length of at least the number
* of components in this ColorSpace.
* @return a float array of length 3.
* @throws ArrayIndexOutOfBoundsException if array length is not
* at least the number of components in this ColorSpace.
*/
public float[] toRGB (float[] colorvalue) {
if (this2srgb == null) {
ColorTransform[] transformList = new ColorTransform [2];
ICC_ColorSpace srgbCS =
(ICC_ColorSpace) ColorSpace.getInstance (CS_sRGB);
PCMM mdl = CMSManager.getModule();
transformList[0] = mdl.createTransform(
thisProfile, ColorTransform.Any, ColorTransform.In);
transformList[1] = mdl.createTransform(
srgbCS.getProfile(), ColorTransform.Any, ColorTransform.Out);
this2srgb = mdl.createTransform(transformList);
if (needScaleInit) {
setComponentScaling();
}
}
int nc = this.getNumComponents();
short tmp[] = new short[nc];
for (int i = 0; i < nc; i++) {
tmp[i] = (short)
((colorvalue[i] - minVal[i]) * invDiffMinMax[i] + 0.5f);
}
tmp = this2srgb.colorConvert(tmp, null);
float[] result = new float [3];
for (int i = 0; i < 3; i++) {
result[i] = ((float) (tmp[i] & 0xffff)) / 65535.0f;
}
return result;
}
/**
* Transforms a color value assumed to be in the default CS_sRGB
* color space into this ColorSpace.
*
* This method transforms color values using algorithms designed
* to produce the best perceptual match between input and output
* colors. In order to do colorimetric conversion of color values,
* you should use the toCIEXYZ
* method of the CS_sRGB color space to first convert from the input
* color space to the CS_CIEXYZ color space, and then use the
* fromCIEXYZ method of this color space to
* convert from CS_CIEXYZ to the output color space.
* See {@link #toCIEXYZ(float[]) toCIEXYZ} and
* {@link #fromCIEXYZ(float[]) fromCIEXYZ} for further information.
*
* @param rgbvalue a float array with length of at least 3.
* @return a float array with length equal to the number of
* components in this ColorSpace.
* @throws ArrayIndexOutOfBoundsException if array length is not
* at least 3.
*/
public float[] fromRGB(float[] rgbvalue) {
if (srgb2this == null) {
ColorTransform[] transformList = new ColorTransform [2];
ICC_ColorSpace srgbCS =
(ICC_ColorSpace) ColorSpace.getInstance (CS_sRGB);
PCMM mdl = CMSManager.getModule();
transformList[0] = mdl.createTransform(
srgbCS.getProfile(), ColorTransform.Any, ColorTransform.In);
transformList[1] = mdl.createTransform(
thisProfile, ColorTransform.Any, ColorTransform.Out);
srgb2this = mdl.createTransform(transformList);
if (needScaleInit) {
setComponentScaling();
}
}
short tmp[] = new short[3];
for (int i = 0; i < 3; i++) {
tmp[i] = (short) ((rgbvalue[i] * 65535.0f) + 0.5f);
}
tmp = srgb2this.colorConvert(tmp, null);
int nc = this.getNumComponents();
float[] result = new float [nc];
for (int i = 0; i < nc; i++) {
result[i] = (((float) (tmp[i] & 0xffff)) / 65535.0f) *
diffMinMax[i] + minVal[i];
}
return result;
}
/**
* Transforms a color value assumed to be in this ColorSpace
* into the CS_CIEXYZ conversion color space.
*
* This method transforms color values using relative colorimetry, * as defined by the ICC Specification. This * means that the XYZ values returned by this method are represented * relative to the D50 white point of the CS_CIEXYZ color space. * This representation is useful in a two-step color conversion * process in which colors are transformed from an input color * space to CS_CIEXYZ and then to an output color space. This * representation is not the same as the XYZ values that would * be measured from the given color value by a colorimeter. * A further transformation is necessary to compute the XYZ values * that would be measured using current CIE recommended practices. * The paragraphs below explain this in more detail. *
* The ICC standard uses a device independent color space (DICS) as the * mechanism for converting color from one device to another device. In * this architecture, colors are converted from the source device's color * space to the ICC DICS and then from the ICC DICS to the destination * device's color space. The ICC standard defines device profiles which * contain transforms which will convert between a device's color space * and the ICC DICS. The overall conversion of colors from a source * device to colors of a destination device is done by connecting the * device-to-DICS transform of the profile for the source device to the * DICS-to-device transform of the profile for the destination device. * For this reason, the ICC DICS is commonly referred to as the profile * connection space (PCS). The color space used in the methods * toCIEXYZ and fromCIEXYZ is the CIEXYZ PCS defined by the ICC * Specification. This is also the color space represented by * ColorSpace.CS_CIEXYZ. *
* The XYZ values of a color are often represented as relative to some * white point, so the actual meaning of the XYZ values cannot be known * without knowing the white point of those values. This is known as * relative colorimetry. The PCS uses a white point of D50, so the XYZ * values of the PCS are relative to D50. For example, white in the PCS * will have the XYZ values of D50, which is defined to be X=.9642, * Y=1.000, and Z=0.8249. This white point is commonly used for graphic * arts applications, but others are often used in other applications. *
* To quantify the color characteristics of a device such as a printer * or monitor, measurements of XYZ values for particular device colors * are typically made. For purposes of this discussion, the term * device XYZ values is used to mean the XYZ values that would be * measured from device colors using current CIE recommended practices. *
* Converting between device XYZ values and the PCS XYZ values returned * by this method corresponds to converting between the device's color * space, as represented by CIE colorimetric values, and the PCS. There * are many factors involved in this process, some of which are quite * subtle. The most important, however, is the adjustment made to account * for differences between the device's white point and the white point of * the PCS. There are many techniques for doing this and it is the * subject of much current research and controversy. Some commonly used * methods are XYZ scaling, the von Kries transform, and the Bradford * transform. The proper method to use depends upon each particular * application. *
* The simplest method is XYZ scaling. In this method each device XYZ * value is converted to a PCS XYZ value by multiplying it by the ratio * of the PCS white point (D50) to the device white point. *
*
* Xd, Yd, Zd are the device XYZ values
* Xdw, Ydw, Zdw are the device XYZ white point values
* Xp, Yp, Zp are the PCS XYZ values
* Xd50, Yd50, Zd50 are the PCS XYZ white point values
*
* Xp = Xd * (Xd50 / Xdw)
* Yp = Yd * (Yd50 / Ydw)
* Zp = Zd * (Zd50 / Zdw)
*
*
* * Conversion from the PCS to the device would be done by inverting these * equations: *
*
* Xd = Xp * (Xdw / Xd50)
* Yd = Yp * (Ydw / Yd50)
* Zd = Zp * (Zdw / Zd50)
*
*
* * Note that the media white point tag in an ICC profile is not the same * as the device white point. The media white point tag is expressed in * PCS values and is used to represent the difference between the XYZ of * device illuminant and the XYZ of the device media when measured under * that illuminant. The device white point is expressed as the device * XYZ values corresponding to white displayed on the device. For * example, displaying the RGB color (1.0, 1.0, 1.0) on an sRGB device * will result in a measured device XYZ value of D65. This will not * be the same as the media white point tag XYZ value in the ICC * profile for an sRGB device. * * @param colorvalue a float array with length of at least the number * of components in this ColorSpace. * @return a float array of length 3. * @throws ArrayIndexOutOfBoundsException if array length is not * at least the number of components in this ColorSpace. */ public float[] toCIEXYZ(float[] colorvalue) { if (this2xyz == null) { ColorTransform[] transformList = new ColorTransform [2]; ICC_ColorSpace xyzCS = (ICC_ColorSpace) ColorSpace.getInstance (CS_CIEXYZ); PCMM mdl = CMSManager.getModule(); try { transformList[0] = mdl.createTransform( thisProfile, ICC_Profile.icRelativeColorimetric, ColorTransform.In); } catch (CMMException e) { transformList[0] = mdl.createTransform( thisProfile, ColorTransform.Any, ColorTransform.In); } transformList[1] = mdl.createTransform( xyzCS.getProfile(), ColorTransform.Any, ColorTransform.Out); this2xyz = mdl.createTransform (transformList); if (needScaleInit) { setComponentScaling(); } } int nc = this.getNumComponents(); short tmp[] = new short[nc]; for (int i = 0; i < nc; i++) { tmp[i] = (short) ((colorvalue[i] - minVal[i]) * invDiffMinMax[i] + 0.5f); } tmp = this2xyz.colorConvert(tmp, null); float ALMOST_TWO = 1.0f + (32767.0f / 32768.0f); // For CIEXYZ, min = 0.0, max = ALMOST_TWO for all components float[] result = new float [3]; for (int i = 0; i < 3; i++) { result[i] = (((float) (tmp[i] & 0xffff)) / 65535.0f) * ALMOST_TWO; } return result; } /** * Transforms a color value assumed to be in the CS_CIEXYZ conversion * color space into this ColorSpace. *
* This method transforms color values using relative colorimetry, * as defined by the ICC Specification. This * means that the XYZ argument values taken by this method are represented * relative to the D50 white point of the CS_CIEXYZ color space. * This representation is useful in a two-step color conversion * process in which colors are transformed from an input color * space to CS_CIEXYZ and then to an output color space. The color * values returned by this method are not those that would produce * the XYZ value passed to the method when measured by a colorimeter. * If you have XYZ values corresponding to measurements made using * current CIE recommended practices, they must be converted to D50 * relative values before being passed to this method. * The paragraphs below explain this in more detail. *
* The ICC standard uses a device independent color space (DICS) as the * mechanism for converting color from one device to another device. In * this architecture, colors are converted from the source device's color * space to the ICC DICS and then from the ICC DICS to the destination * device's color space. The ICC standard defines device profiles which * contain transforms which will convert between a device's color space * and the ICC DICS. The overall conversion of colors from a source * device to colors of a destination device is done by connecting the * device-to-DICS transform of the profile for the source device to the * DICS-to-device transform of the profile for the destination device. * For this reason, the ICC DICS is commonly referred to as the profile * connection space (PCS). The color space used in the methods * toCIEXYZ and fromCIEXYZ is the CIEXYZ PCS defined by the ICC * Specification. This is also the color space represented by * ColorSpace.CS_CIEXYZ. *
* The XYZ values of a color are often represented as relative to some * white point, so the actual meaning of the XYZ values cannot be known * without knowing the white point of those values. This is known as * relative colorimetry. The PCS uses a white point of D50, so the XYZ * values of the PCS are relative to D50. For example, white in the PCS * will have the XYZ values of D50, which is defined to be X=.9642, * Y=1.000, and Z=0.8249. This white point is commonly used for graphic * arts applications, but others are often used in other applications. *
* To quantify the color characteristics of a device such as a printer * or monitor, measurements of XYZ values for particular device colors * are typically made. For purposes of this discussion, the term * device XYZ values is used to mean the XYZ values that would be * measured from device colors using current CIE recommended practices. *
* Converting between device XYZ values and the PCS XYZ values taken as * arguments by this method corresponds to converting between the device's * color space, as represented by CIE colorimetric values, and the PCS. * There are many factors involved in this process, some of which are quite * subtle. The most important, however, is the adjustment made to account * for differences between the device's white point and the white point of * the PCS. There are many techniques for doing this and it is the * subject of much current research and controversy. Some commonly used * methods are XYZ scaling, the von Kries transform, and the Bradford * transform. The proper method to use depends upon each particular * application. *
* The simplest method is XYZ scaling. In this method each device XYZ * value is converted to a PCS XYZ value by multiplying it by the ratio * of the PCS white point (D50) to the device white point. *
*
* Xd, Yd, Zd are the device XYZ values
* Xdw, Ydw, Zdw are the device XYZ white point values
* Xp, Yp, Zp are the PCS XYZ values
* Xd50, Yd50, Zd50 are the PCS XYZ white point values
*
* Xp = Xd * (Xd50 / Xdw)
* Yp = Yd * (Yd50 / Ydw)
* Zp = Zd * (Zd50 / Zdw)
*
*
* * Conversion from the PCS to the device would be done by inverting these * equations: *
*
* Xd = Xp * (Xdw / Xd50)
* Yd = Yp * (Ydw / Yd50)
* Zd = Zp * (Zdw / Zd50)
*
*
* * Note that the media white point tag in an ICC profile is not the same * as the device white point. The media white point tag is expressed in * PCS values and is used to represent the difference between the XYZ of * device illuminant and the XYZ of the device media when measured under * that illuminant. The device white point is expressed as the device * XYZ values corresponding to white displayed on the device. For * example, displaying the RGB color (1.0, 1.0, 1.0) on an sRGB device * will result in a measured device XYZ value of D65. This will not * be the same as the media white point tag XYZ value in the ICC * profile for an sRGB device. * * @param colorvalue a float array with length of at least 3. * @return a float array with length equal to the number of * components in this ColorSpace. * @throws ArrayIndexOutOfBoundsException if array length is not * at least 3. */ public float[] fromCIEXYZ(float[] colorvalue) { if (xyz2this == null) { ColorTransform[] transformList = new ColorTransform [2]; ICC_ColorSpace xyzCS = (ICC_ColorSpace) ColorSpace.getInstance (CS_CIEXYZ); PCMM mdl = CMSManager.getModule(); transformList[0] = mdl.createTransform ( xyzCS.getProfile(), ColorTransform.Any, ColorTransform.In); try { transformList[1] = mdl.createTransform( thisProfile, ICC_Profile.icRelativeColorimetric, ColorTransform.Out); } catch (CMMException e) { transformList[1] = CMSManager.getModule().createTransform( thisProfile, ColorTransform.Any, ColorTransform.Out); } xyz2this = mdl.createTransform(transformList); if (needScaleInit) { setComponentScaling(); } } short tmp[] = new short[3]; float ALMOST_TWO = 1.0f + (32767.0f / 32768.0f); float factor = 65535.0f / ALMOST_TWO; // For CIEXYZ, min = 0.0, max = ALMOST_TWO for all components for (int i = 0; i < 3; i++) { tmp[i] = (short) ((colorvalue[i] * factor) + 0.5f); } tmp = xyz2this.colorConvert(tmp, null); int nc = this.getNumComponents(); float[] result = new float [nc]; for (int i = 0; i < nc; i++) { result[i] = (((float) (tmp[i] & 0xffff)) / 65535.0f) * diffMinMax[i] + minVal[i]; } return result; } /** * Returns the minimum normalized color component value for the * specified component. For TYPE_XYZ spaces, this method returns * minimum values of 0.0 for all components. For TYPE_Lab spaces, * this method returns 0.0 for L and -128.0 for a and b components. * This is consistent with the encoding of the XYZ and Lab Profile * Connection Spaces in the ICC specification. For all other types, this * method returns 0.0 for all components. When using an ICC_ColorSpace * with a profile that requires different minimum component values, * it is necessary to subclass this class and override this method. * @param component The component index. * @return The minimum normalized component value. * @throws IllegalArgumentException if component is less than 0 or * greater than numComponents - 1. * @since 1.4 */ public float getMinValue(int component) { if ((component < 0) || (component > this.getNumComponents() - 1)) { throw new IllegalArgumentException( "Component index out of range: " + component); } return minVal[component]; } /** * Returns the maximum normalized color component value for the * specified component. For TYPE_XYZ spaces, this method returns * maximum values of 1.0 + (32767.0 / 32768.0) for all components. * For TYPE_Lab spaces, * this method returns 100.0 for L and 127.0 for a and b components. * This is consistent with the encoding of the XYZ and Lab Profile * Connection Spaces in the ICC specification. For all other types, this * method returns 1.0 for all components. When using an ICC_ColorSpace * with a profile that requires different maximum component values, * it is necessary to subclass this class and override this method. * @param component The component index. * @return The maximum normalized component value. * @throws IllegalArgumentException if component is less than 0 or * greater than numComponents - 1. * @since 1.4 */ public float getMaxValue(int component) { if ((component < 0) || (component > this.getNumComponents() - 1)) { throw new IllegalArgumentException( "Component index out of range: " + component); } return maxVal[component]; } private void setMinMax() { int nc = this.getNumComponents(); int type = this.getType(); minVal = new float[nc]; maxVal = new float[nc]; if (type == ColorSpace.TYPE_Lab) { minVal[0] = 0.0f; // L maxVal[0] = 100.0f; minVal[1] = -128.0f; // a maxVal[1] = 127.0f; minVal[2] = -128.0f; // b maxVal[2] = 127.0f; } else if (type == ColorSpace.TYPE_XYZ) { minVal[0] = minVal[1] = minVal[2] = 0.0f; // X, Y, Z maxVal[0] = maxVal[1] = maxVal[2] = 1.0f + (32767.0f/ 32768.0f); } else { for (int i = 0; i < nc; i++) { minVal[i] = 0.0f; maxVal[i] = 1.0f; } } } private void setComponentScaling() { int nc = this.getNumComponents(); diffMinMax = new float[nc]; invDiffMinMax = new float[nc]; for (int i = 0; i < nc; i++) { minVal[i] = this.getMinValue(i); // in case getMinVal is overridden maxVal[i] = this.getMaxValue(i); // in case getMaxVal is overridden diffMinMax[i] = maxVal[i] - minVal[i]; invDiffMinMax[i] = 65535.0f / diffMinMax[i]; } needScaleInit = false; } }