package eecs2030.test3; import java.awt.Color; /** * A class that represents gray values for grayscale (black-and-white) * images. A gray value can be an integer value between 0 and 255, * or a double value between 0.0 and 1.0. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
gray value as double   gray value as int
0.00
1.0 / 255.01
2.0 / 255.02
3.0 / 255.03
......
254.0 / 255.0254
1.0255
* *

* A Gray instance can be created using any double value * between 0.0 and 1.0; it is not required that there be an exact * match between the double gray value and an int gray value. * See {@link #toInt} for details on how a double gray value is * converted to an int gray value. * * @author EECS2030 Fall 2016 * */ public final class Gray implements Comparable { /** * The minimum double gray value. */ public final static double MIN_DOUBLE_VALUE = 0.0; /** * The maximum double gray value. */ public final static double MAX_DOUBLE_VALUE = 1.0; /** * The minimum int gray value. */ public final static int MIN_INT_VALUE = 0; /** * The maximum int gray value. */ public final static int MAX_INT_VALUE = 255; /** * YOU SHOULD ADD WHATEVER FIELDS YOU REQUIRE BELOW HERE */ /** * Initializes the gray value of this object to g. * The value returned by asDouble() will be equal to * g: * * 

     * double g = 0.12345;
     * Gray gray = new Gray(g);
     * double value = gray.asDouble();   // value is equal to g
     *
* * @param g a gray value between 0.0 and 1.0 * @throws IllegalArgumentException if g is less than 0.0 or greater than 1.0 */ public Gray(double g) { } /** * Initializes the gray value of this object to g. * The value returned by asInt() will be equal to * g: * * 
     * int g = 128;
     * Gray gray = new Gray(g);
     * int value = gray.asInt();   // value is equal to g
     *
* * @param g a gray value between 0 and 255 * @throws IllegalArgumentException if g is less than 0 or greater than 255 */ public Gray(int g) { } /** * Initializes the gray value of this object by copying another * Gray object. * * @param other a Gray object to copy */ public Gray(Gray other) { } /** * Returns the gray value of this object as an int. If this * gray object was created using a double value, then that * double value is converted to the equivalent int gray * value and returned (see {@link #toInt} for details). * * 
     * Gray gray = new Gray(192);
     * int value = gray.asInt();    // value is equal to 192
     * 
     * gray = new Gray(1.0);
     * value = gray.asInt();        // value is equal to 255
     *
* * @return the gray value of this object expressed as an integer */ public int asInt() { return 0; } /** * Returns the gray value of this object as a double. If this * gray object was created using an int value, then that * int value is converted to the equivalent double gray * value and returned (see {@link #toDouble} for details). * * 
     * Gray gray = new Gray(0.5);
     * double value = gray.asDouble();    // value is equal to 0.5
     * 
     * gray = new Gray(255);
     * value = gray.asDouble();           // value is equal to 1.0
     *
* * @return the gray value of this object expressed as a double */ public double asDouble() { return 0.0; } /** * Converts an integer gray value to its equivalent double gray value. * The equivalent double value is equal to * value / Gray.MAX_DOUBLE_VALUE * * @param value a gray value between 0 and 255 * @return the equivalent double gray value * @throws IllegalArgumentException if value is less than 0 or greater than 255 */ public static double toDouble(int value) { return 0.0; } /** * Converts a double gray value to its equivalent int gray value. * The equivalent int value is equal to round(Gray.MAX_DOUBLE_VALUE × value) * where round rounds the computed value to the nearest int value. * * @param value a gray value between 0.0 and 1.0 * @return the equivalent int gray value * @throws IllegalArgumentException if value is less than 0.0 or greater than 1.0 */ public static int toInt(double value) { return 0; } /** * Creates a Gray instance from a Color. * The gray value of a color is given by * 0.299 × R + 0.587 × G + 0.114 × B * where R is the red value of the color, * G is the green value of the color, * B is the blue value of the color, and all of R, * G, and B are double values between 0.0 and 1.0. * * @param c a color * @return a Gray instance */ public static Gray fromRGB(Color c) { double red = (double) c.getRed() / Gray.MAX_INT_VALUE; return null; } /** * Returns a string representation of this Gray instance. * The string is simply the gray value of this instance. * * 
     * Gray gray = new Gray(18);
     * String s = gray.toString();    // s is equal to "18"
     * 
     * gray = new Gray(0.125);
     * s = gray.toString();           // s is equal to "0.125"
     *
* * @return a string representation of this instance */ @Override public String toString() { return ""; } /** * Compares two Gray instances by their gray values. * The instances are compared using their gray values represented * as double values (between 0.0 and 1.0). Returns:

* -1 if this gray value is less than the other gray value,
* 1 if this gray value is greater than the other gray value, and
* 0 otherwise. * * @return -1, 1, or 0 as indicated in the description above */ @Override public int compareTo(Gray other) { return 0; } /** * Compares two Gray instances for equality. * The result is true if and only if the argument is * not null and is a Gray instance whose * gray value is equal to this instance's gray value. The gray * levels are checked for equality by converting them to int * values (between 0 and 255) and comparing the two int values. * * @return true if the int gray levels of the two instances * are equal, and false otherwise */ @Override public boolean equals(Object obj) { // 1. you may use the eclipse generated version of equals and hashCode // 2. you must modify the eclipse generated version of equals to // satisfy the API stated above // 3. you may leave or remove the eclipse generated version of hashCode; // it won't be marked return false; } }