/*
 * @(#)ICC_ProfileGray.java	1.17 00/02/02
 *
 * Copyright 1997-2000 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */

/**********************************************************************
 **********************************************************************
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 *** COPYRIGHT (c) Eastman Kodak Company, 1997                      ***
 *** As  an unpublished  work pursuant to Title 17 of the United    ***
 *** States Code.  All rights reserved.                             ***
 **********************************************************************
 **********************************************************************
 **********************************************************************/

package java.awt.color;

import java.awt.image.LookupTable;
import sun.awt.color.ProfileDeferralInfo;

/**
 *
 * A subclass of the ICC_Profile class which represents profiles
 * which meet the following criteria: the color space type of the
 * profile is TYPE_GRAY and the profile includes the grayTRCTag and
 * mediaWhitePointTag tags.  Examples of this kind of profile are
 * monochrome input profiles, monochrome display profiles, and
 * monochrome output profiles.  The getInstance methods in the
 * ICC_Profile class will
 * return an ICC_ProfileGray object when the above conditions are
 * met.  The advantage of this class is that it provides a lookup
 * table that Java or native methods may be able to use directly to
 * optimize color conversion in some cases.
 * <p>
 * To transform from a GRAY device profile color space to the CIEXYZ Profile
 * Connection Space, the device gray component is transformed by
 * a lookup through the tone reproduction curve (TRC).  The result is
 * treated as the achromatic component of the PCS.
<pre>

                PCSY = grayTRC[deviceGray]

</pre>
 * The inverse transform is done by converting the PCS Y components to
 * device Gray via the inverse of the grayTRC.
 * <p>
 */



public class ICC_ProfileGray
extends ICC_Profile {

    /**
     * Constructs a new ICC_ProfileGray from a CMM ID.
     */
    ICC_ProfileGray(long ID) {
        super(ID);
    }

    /**
     * Constructs a new ICC_ProfileGray from a ProfileDeferralInfo object.
     */
    ICC_ProfileGray(ProfileDeferralInfo pdi) {
        super(pdi);
    }


    /**
     * Returns a float array of length 3 containing the X, Y, and Z
     * components of the mediaWhitePointTag in the ICC profile.
     */
    public float[] getMediaWhitePoint() {
        return super.getMediaWhitePoint();
    }


    /**
     * Returns a gamma value representing the tone reproduction
     * curve (TRC).  If the profile represents the TRC as a table rather
     * than a single gamma value, then an exception is thrown.  In this
     * case the actual table can be obtained via getTRC().  When
     * using a gamma value, the PCS Y component is computed as follows:
<pre>

                          gamma
         PCSY = deviceGray

</pre>
     * @return the gamma value as a float.
     * @exception ProfileDataException if the profile does not specify
     *            the TRC as a single gamma value.
     */
    public float getGamma() {
    float theGamma;

        theGamma = super.getGamma(ICC_Profile.icSigGrayTRCTag);
        return theGamma;
    }

    /**
     * Returns the TRC as an array of shorts.  If the profile has
     * specified the TRC as linear (gamma = 1.0) or as a simple gamma
     * value, this method throws an exception, and the getGamma() method
     * should be used to get the gamma value.  Otherwise the short array
     * returned here represents a lookup table where the input Gray 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 length-1.
     * Interpolation may be used to generate output values for
     * input values which 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, i.e. the values are really unsigned
     * short values, although they are returned in a short array.
     * @return a short array representing the TRC.
     * @exception ProfileDataException if the profile does not specify
     *            the TRC as a table.
     */
    public short[] getTRC() {
    short[]    theTRC;

        theTRC = super.getTRC(ICC_Profile.icSigGrayTRCTag);
        return theTRC;
    }

}