Convert RGB values to color name
Here is a working sample code that does that. It converts an rgb/hex value/awt color into the closest color name.
import java.awt.Color;
import java.util.ArrayList;
/**
* Java Code to get a color name from rgb/hex value/awt color
*
* The part of looking up a color name from the rgb values is edited from
* https://gist.github.com/nightlark/6482130#file-gistfile1-java (that has some errors) by Ryan Mast (nightlark)
*
* @author Xiaoxiao Li
*
*/
public class ColorUtils {
/**
* Initialize the color list that we have.
*/
private ArrayList<ColorName> initColorList() {
ArrayList<ColorName> colorList = new ArrayList<ColorName>();
colorList.add(new ColorName("AliceBlue", 0xF0, 0xF8, 0xFF));
colorList.add(new ColorName("AntiqueWhite", 0xFA, 0xEB, 0xD7));
colorList.add(new ColorName("Aqua", 0x00, 0xFF, 0xFF));
colorList.add(new ColorName("Aquamarine", 0x7F, 0xFF, 0xD4));
colorList.add(new ColorName("Azure", 0xF0, 0xFF, 0xFF));
colorList.add(new ColorName("Beige", 0xF5, 0xF5, 0xDC));
colorList.add(new ColorName("Bisque", 0xFF, 0xE4, 0xC4));
colorList.add(new ColorName("Black", 0x00, 0x00, 0x00));
colorList.add(new ColorName("BlanchedAlmond", 0xFF, 0xEB, 0xCD));
colorList.add(new ColorName("Blue", 0x00, 0x00, 0xFF));
colorList.add(new ColorName("BlueViolet", 0x8A, 0x2B, 0xE2));
colorList.add(new ColorName("Brown", 0xA5, 0x2A, 0x2A));
colorList.add(new ColorName("BurlyWood", 0xDE, 0xB8, 0x87));
colorList.add(new ColorName("CadetBlue", 0x5F, 0x9E, 0xA0));
colorList.add(new ColorName("Chartreuse", 0x7F, 0xFF, 0x00));
colorList.add(new ColorName("Chocolate", 0xD2, 0x69, 0x1E));
colorList.add(new ColorName("Coral", 0xFF, 0x7F, 0x50));
colorList.add(new ColorName("CornflowerBlue", 0x64, 0x95, 0xED));
colorList.add(new ColorName("Cornsilk", 0xFF, 0xF8, 0xDC));
colorList.add(new ColorName("Crimson", 0xDC, 0x14, 0x3C));
colorList.add(new ColorName("Cyan", 0x00, 0xFF, 0xFF));
colorList.add(new ColorName("DarkBlue", 0x00, 0x00, 0x8B));
colorList.add(new ColorName("DarkCyan", 0x00, 0x8B, 0x8B));
colorList.add(new ColorName("DarkGoldenRod", 0xB8, 0x86, 0x0B));
colorList.add(new ColorName("DarkGray", 0xA9, 0xA9, 0xA9));
colorList.add(new ColorName("DarkGreen", 0x00, 0x64, 0x00));
colorList.add(new ColorName("DarkKhaki", 0xBD, 0xB7, 0x6B));
colorList.add(new ColorName("DarkMagenta", 0x8B, 0x00, 0x8B));
colorList.add(new ColorName("DarkOliveGreen", 0x55, 0x6B, 0x2F));
colorList.add(new ColorName("DarkOrange", 0xFF, 0x8C, 0x00));
colorList.add(new ColorName("DarkOrchid", 0x99, 0x32, 0xCC));
colorList.add(new ColorName("DarkRed", 0x8B, 0x00, 0x00));
colorList.add(new ColorName("DarkSalmon", 0xE9, 0x96, 0x7A));
colorList.add(new ColorName("DarkSeaGreen", 0x8F, 0xBC, 0x8F));
colorList.add(new ColorName("DarkSlateBlue", 0x48, 0x3D, 0x8B));
colorList.add(new ColorName("DarkSlateGray", 0x2F, 0x4F, 0x4F));
colorList.add(new ColorName("DarkTurquoise", 0x00, 0xCE, 0xD1));
colorList.add(new ColorName("DarkViolet", 0x94, 0x00, 0xD3));
colorList.add(new ColorName("DeepPink", 0xFF, 0x14, 0x93));
colorList.add(new ColorName("DeepSkyBlue", 0x00, 0xBF, 0xFF));
colorList.add(new ColorName("DimGray", 0x69, 0x69, 0x69));
colorList.add(new ColorName("DodgerBlue", 0x1E, 0x90, 0xFF));
colorList.add(new ColorName("FireBrick", 0xB2, 0x22, 0x22));
colorList.add(new ColorName("FloralWhite", 0xFF, 0xFA, 0xF0));
colorList.add(new ColorName("ForestGreen", 0x22, 0x8B, 0x22));
colorList.add(new ColorName("Fuchsia", 0xFF, 0x00, 0xFF));
colorList.add(new ColorName("Gainsboro", 0xDC, 0xDC, 0xDC));
colorList.add(new ColorName("GhostWhite", 0xF8, 0xF8, 0xFF));
colorList.add(new ColorName("Gold", 0xFF, 0xD7, 0x00));
colorList.add(new ColorName("GoldenRod", 0xDA, 0xA5, 0x20));
colorList.add(new ColorName("Gray", 0x80, 0x80, 0x80));
colorList.add(new ColorName("Green", 0x00, 0x80, 0x00));
colorList.add(new ColorName("GreenYellow", 0xAD, 0xFF, 0x2F));
colorList.add(new ColorName("HoneyDew", 0xF0, 0xFF, 0xF0));
colorList.add(new ColorName("HotPink", 0xFF, 0x69, 0xB4));
colorList.add(new ColorName("IndianRed", 0xCD, 0x5C, 0x5C));
colorList.add(new ColorName("Indigo", 0x4B, 0x00, 0x82));
colorList.add(new ColorName("Ivory", 0xFF, 0xFF, 0xF0));
colorList.add(new ColorName("Khaki", 0xF0, 0xE6, 0x8C));
colorList.add(new ColorName("Lavender", 0xE6, 0xE6, 0xFA));
colorList.add(new ColorName("LavenderBlush", 0xFF, 0xF0, 0xF5));
colorList.add(new ColorName("LawnGreen", 0x7C, 0xFC, 0x00));
colorList.add(new ColorName("LemonChiffon", 0xFF, 0xFA, 0xCD));
colorList.add(new ColorName("LightBlue", 0xAD, 0xD8, 0xE6));
colorList.add(new ColorName("LightCoral", 0xF0, 0x80, 0x80));
colorList.add(new ColorName("LightCyan", 0xE0, 0xFF, 0xFF));
colorList.add(new ColorName("LightGoldenRodYellow", 0xFA, 0xFA, 0xD2));
colorList.add(new ColorName("LightGray", 0xD3, 0xD3, 0xD3));
colorList.add(new ColorName("LightGreen", 0x90, 0xEE, 0x90));
colorList.add(new ColorName("LightPink", 0xFF, 0xB6, 0xC1));
colorList.add(new ColorName("LightSalmon", 0xFF, 0xA0, 0x7A));
colorList.add(new ColorName("LightSeaGreen", 0x20, 0xB2, 0xAA));
colorList.add(new ColorName("LightSkyBlue", 0x87, 0xCE, 0xFA));
colorList.add(new ColorName("LightSlateGray", 0x77, 0x88, 0x99));
colorList.add(new ColorName("LightSteelBlue", 0xB0, 0xC4, 0xDE));
colorList.add(new ColorName("LightYellow", 0xFF, 0xFF, 0xE0));
colorList.add(new ColorName("Lime", 0x00, 0xFF, 0x00));
colorList.add(new ColorName("LimeGreen", 0x32, 0xCD, 0x32));
colorList.add(new ColorName("Linen", 0xFA, 0xF0, 0xE6));
colorList.add(new ColorName("Magenta", 0xFF, 0x00, 0xFF));
colorList.add(new ColorName("Maroon", 0x80, 0x00, 0x00));
colorList.add(new ColorName("MediumAquaMarine", 0x66, 0xCD, 0xAA));
colorList.add(new ColorName("MediumBlue", 0x00, 0x00, 0xCD));
colorList.add(new ColorName("MediumOrchid", 0xBA, 0x55, 0xD3));
colorList.add(new ColorName("MediumPurple", 0x93, 0x70, 0xDB));
colorList.add(new ColorName("MediumSeaGreen", 0x3C, 0xB3, 0x71));
colorList.add(new ColorName("MediumSlateBlue", 0x7B, 0x68, 0xEE));
colorList.add(new ColorName("MediumSpringGreen", 0x00, 0xFA, 0x9A));
colorList.add(new ColorName("MediumTurquoise", 0x48, 0xD1, 0xCC));
colorList.add(new ColorName("MediumVioletRed", 0xC7, 0x15, 0x85));
colorList.add(new ColorName("MidnightBlue", 0x19, 0x19, 0x70));
colorList.add(new ColorName("MintCream", 0xF5, 0xFF, 0xFA));
colorList.add(new ColorName("MistyRose", 0xFF, 0xE4, 0xE1));
colorList.add(new ColorName("Moccasin", 0xFF, 0xE4, 0xB5));
colorList.add(new ColorName("NavajoWhite", 0xFF, 0xDE, 0xAD));
colorList.add(new ColorName("Navy", 0x00, 0x00, 0x80));
colorList.add(new ColorName("OldLace", 0xFD, 0xF5, 0xE6));
colorList.add(new ColorName("Olive", 0x80, 0x80, 0x00));
colorList.add(new ColorName("OliveDrab", 0x6B, 0x8E, 0x23));
colorList.add(new ColorName("Orange", 0xFF, 0xA5, 0x00));
colorList.add(new ColorName("OrangeRed", 0xFF, 0x45, 0x00));
colorList.add(new ColorName("Orchid", 0xDA, 0x70, 0xD6));
colorList.add(new ColorName("PaleGoldenRod", 0xEE, 0xE8, 0xAA));
colorList.add(new ColorName("PaleGreen", 0x98, 0xFB, 0x98));
colorList.add(new ColorName("PaleTurquoise", 0xAF, 0xEE, 0xEE));
colorList.add(new ColorName("PaleVioletRed", 0xDB, 0x70, 0x93));
colorList.add(new ColorName("PapayaWhip", 0xFF, 0xEF, 0xD5));
colorList.add(new ColorName("PeachPuff", 0xFF, 0xDA, 0xB9));
colorList.add(new ColorName("Peru", 0xCD, 0x85, 0x3F));
colorList.add(new ColorName("Pink", 0xFF, 0xC0, 0xCB));
colorList.add(new ColorName("Plum", 0xDD, 0xA0, 0xDD));
colorList.add(new ColorName("PowderBlue", 0xB0, 0xE0, 0xE6));
colorList.add(new ColorName("Purple", 0x80, 0x00, 0x80));
colorList.add(new ColorName("Red", 0xFF, 0x00, 0x00));
colorList.add(new ColorName("RosyBrown", 0xBC, 0x8F, 0x8F));
colorList.add(new ColorName("RoyalBlue", 0x41, 0x69, 0xE1));
colorList.add(new ColorName("SaddleBrown", 0x8B, 0x45, 0x13));
colorList.add(new ColorName("Salmon", 0xFA, 0x80, 0x72));
colorList.add(new ColorName("SandyBrown", 0xF4, 0xA4, 0x60));
colorList.add(new ColorName("SeaGreen", 0x2E, 0x8B, 0x57));
colorList.add(new ColorName("SeaShell", 0xFF, 0xF5, 0xEE));
colorList.add(new ColorName("Sienna", 0xA0, 0x52, 0x2D));
colorList.add(new ColorName("Silver", 0xC0, 0xC0, 0xC0));
colorList.add(new ColorName("SkyBlue", 0x87, 0xCE, 0xEB));
colorList.add(new ColorName("SlateBlue", 0x6A, 0x5A, 0xCD));
colorList.add(new ColorName("SlateGray", 0x70, 0x80, 0x90));
colorList.add(new ColorName("Snow", 0xFF, 0xFA, 0xFA));
colorList.add(new ColorName("SpringGreen", 0x00, 0xFF, 0x7F));
colorList.add(new ColorName("SteelBlue", 0x46, 0x82, 0xB4));
colorList.add(new ColorName("Tan", 0xD2, 0xB4, 0x8C));
colorList.add(new ColorName("Teal", 0x00, 0x80, 0x80));
colorList.add(new ColorName("Thistle", 0xD8, 0xBF, 0xD8));
colorList.add(new ColorName("Tomato", 0xFF, 0x63, 0x47));
colorList.add(new ColorName("Turquoise", 0x40, 0xE0, 0xD0));
colorList.add(new ColorName("Violet", 0xEE, 0x82, 0xEE));
colorList.add(new ColorName("Wheat", 0xF5, 0xDE, 0xB3));
colorList.add(new ColorName("White", 0xFF, 0xFF, 0xFF));
colorList.add(new ColorName("WhiteSmoke", 0xF5, 0xF5, 0xF5));
colorList.add(new ColorName("Yellow", 0xFF, 0xFF, 0x00));
colorList.add(new ColorName("YellowGreen", 0x9A, 0xCD, 0x32));
return colorList;
}
/**
* Get the closest color name from our list
*
* @param r
* @param g
* @param b
* @return
*/
public String getColorNameFromRgb(int r, int g, int b) {
ArrayList<ColorName> colorList = initColorList();
ColorName closestMatch = null;
int minMSE = Integer.MAX_VALUE;
int mse;
for (ColorName c : colorList) {
mse = c.computeMSE(r, g, b);
if (mse < minMSE) {
minMSE = mse;
closestMatch = c;
}
}
if (closestMatch != null) {
return closestMatch.getName();
} else {
return "No matched color name.";
}
}
/**
* Convert hexColor to rgb, then call getColorNameFromRgb(r, g, b)
*
* @param hexColor
* @return
*/
public String getColorNameFromHex(int hexColor) {
int r = (hexColor & 0xFF0000) >> 16;
int g = (hexColor & 0xFF00) >> 8;
int b = (hexColor & 0xFF);
return getColorNameFromRgb(r, g, b);
}
public int colorToHex(Color c) {
return Integer.decode("0x"
+ Integer.toHexString(c.getRGB()).substring(2));
}
public String getColorNameFromColor(Color color) {
return getColorNameFromRgb(color.getRed(), color.getGreen(),
color.getBlue());
}
/**
* SubClass of ColorUtils. In order to lookup color name
*
* @author Xiaoxiao Li
*
*/
public class ColorName {
public int r, g, b;
public String name;
public ColorName(String name, int r, int g, int b) {
this.r = r;
this.g = g;
this.b = b;
this.name = name;
}
public int computeMSE(int pixR, int pixG, int pixB) {
return (int) (((pixR - r) * (pixR - r) + (pixG - g) * (pixG - g) + (pixB - b)
* (pixB - b)) / 3);
}
public int getR() {
return r;
}
public int getG() {
return g;
}
public int getB() {
return b;
}
public String getName() {
return name;
}
}
}
- Populate a list of "known" colors.
-
For each known color compute:
rgbDistance = Math.abs(myColor.getRed() - colorI.getRed() + Math.abs(myColor.getGreen() - colorI.getGreen()) + Math.abs(myColor.getBlue() - colorI.getBlue()) Return the name of
colorIfor whichrgbDistancewas smallest.
Hmm, that's a kind of fun problem. I can think of a few solutions:
You could do a bit of guesswork depending on the relationships between the R-G-B values (for example, if one color is very dominant you guess that one, but if there's a bit of other color you get more and more likely to guess the combination of those two emitted colors, if all three are close to equal then guess white, grey, or black depending on how high the average of the three values is, if two are high and the other is low guess the combinatoin of the two, etc. etc.)
You could go for a more learning approach where you set some initial guesses (as above) and then improve on those based on feedback from users.
Unfortunately this problem is relatively subjective (although the question is not!) as people's perception of color varies widely between culture and even gender (see Randall Munroe's "study" on it ).
If you want a specific subset of RGB values (like the ones that are given constants in Java or C# you can iterate through each and compare, finally returning some default value if it's not equal to any of them).
[EDIT]
Ahh! Colorblind users eh? Have you considered creating a setting which lets the user specify which colors they have trouble differentiating? If you did that you could let them know that something is "20% Redder than Green" (if, for instance, they had red-green colorblindness, which is most common). That would be pretty simple. They select a pixel, and you follow this pseudocode:
if( userColorTrouble == RedGreen )
{
int redVal = colorInQuestion.GetRed();
int greenVal = colorInQuestion.GetGreen();
if( redVal > greenVal )
{
return "The color is " + (double)redVal / (redVal + greenVal) - .5d + "% redder than green";
}
else
{
return "The color is " + (double)greenVal / (redVal + greenVal) - .5d + "% greener than red";
}
}
That could be a simpler, and more useful solution.