icy.util

Class ColorUtil

java.lang.Object

icy.util.ColorUtil

public class ColorUtil
extends java.lang.Object

Color utilities class.

Author:

Stephane

Field Summary

Fields

Modifier and Type	Field and Description
static java.awt.color.ColorSpace	sRGB RGB colorSpace

Constructor Summary

Constructors

Constructor and Description
ColorUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static java.awt.Color	add(java.awt.Color c1, java.awt.Color c2) Add 2 colors
static java.awt.Color	add(java.awt.Color c1, java.awt.Color c2, boolean useAlpha) Add 2 colors
static float[]	fromHSV(float[] hsv) Convert the specified HSV color to RGB color.
static float[]	fromXYZ(float[] xyz) Convert the specified XYZ color to RGB color.
static java.awt.Color[]	generateRainbow(float saturation, float brightness, int size, boolean black, boolean white, boolean gray) Generates a rainbow color table (HSV ramp) of the specified size.
static java.awt.Color[]	generateRainbow(int size) Generates a rainbow color table (HSV ramp) of the specified size.
static java.awt.Color[]	generateRainbow(int size, boolean black, boolean white, boolean gray) Generates a rainbow color table (HSV ramp) of the specified size.
static java.awt.Color	getColorFromWavelength(double wavelength) Converts a wavelength into a Color object.
static double	getDistance(java.awt.Color c1, java.awt.Color c2, boolean hsv) Compute and returns the distance between the 2 colors.
static java.awt.Color	getDominantColor(java.awt.Color[] colors) Returns the dominant color from the specified color array.
static java.awt.Color	getDominantColor(java.awt.Color[] colors, int binNumber) Returns the dominant color from the specified color array.
static java.awt.Color	getGrayColorLum(java.awt.Color c) Convert to gray level color (from luminance calculation)
static java.awt.Color	getGrayColorMix(java.awt.Color c) Convert to gray level color (simple RGB mix)
static int	getGrayMix(java.awt.Color c) get to gray level (simple RGB mix)
static int	getGrayMix(int rgb) get to gray level (simple RGB mix)
static int	getLuminance(java.awt.Color c) Return luminance (in [0..255] range)
static java.awt.Color	getRandomColor() Returns a random color.
static boolean	isBlack(java.awt.Color color) Returns true if the specified color is pure black (alpha is not verified)
static java.awt.Color	mix(java.awt.Color c1, java.awt.Color c2) Mix 2 colors (no alpha)
static java.awt.Color	mix(java.awt.Color c1, java.awt.Color c2, boolean useAlpha) Mix 2 colors without "priority" color
static java.awt.Color	mix(java.awt.Color c1, java.awt.Color c2, float ratio) Mix 2 colors using the following ratio for mixing: 0f means 100% of color 1 and 0% of color 2 0.5f means 50% of color 1 and 50% of color 2 1f means 0% of color 1 and 100% of color 2
static java.awt.Color	mixOver(java.awt.Color backColor, java.awt.Color frontColor) Mix 2 colors with priority color
static java.awt.Color	sub(java.awt.Color c1, java.awt.Color c2) Subtract 2 colors
static java.awt.Color	sub(java.awt.Color c1, java.awt.Color c2, boolean useAlpha) Sub 2 colors
static float[]	toHSV(java.awt.Color c) Convert the specified color to HSV color.
static float[]	toHSV(float[] rgb) Convert the specified RGB color to HSV color.
static float[]	toLAB(java.awt.Color c) Convert the specified color to LAB color.
static float[]	toLAB(float[] rgb) Convert the specified RGB color to LAB color.
static java.lang.String	toString(java.awt.Color color) Get String representation of the specified color.
static java.lang.String	toString(java.awt.Color color, boolean hexa) Get String representation of the specified Color value.
static java.lang.String	toString(java.awt.Color color, boolean hexa, java.lang.String sep) Get String representation of the specified color.
static java.lang.String	toString(int rgb) Get String representation of the specified rgb value.
static java.lang.String	toString(int rgb, boolean hexa) Get String representation of the specified rgb value.
static java.lang.String	toString(int rgb, boolean hexa, java.lang.String sep) Get String representation of the specified rgb value.
static float[]	toXYZ(java.awt.Color c) Convert the specified color to XYZ color.
static float[]	toXYZ(float[] rgb) Convert the specified RGB color to XYZ color.
static java.awt.Color	xor(java.awt.Color c) Get opposite (XORed) color
static float[]	XYZtoLAB(float[] xyz) Convert the specified XYZ color to LAB color.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

sRGB

public static final java.awt.color.ColorSpace sRGB

RGB colorSpace

Constructor Detail

ColorUtil

public ColorUtil()

Method Detail

getRandomColor

public static java.awt.Color getRandomColor()

Returns a random color.

generateRainbow

public static java.awt.Color[] generateRainbow(float saturation,
                               float brightness,
                               int size,
                               boolean black,
                               boolean white,
                               boolean gray)

Generates a rainbow color table (HSV ramp) of the specified size.

Parameters:

saturation - saturation factor (from 0 to 1).

brightness - brightness factor (from 0 to 1).

size - the size of rainbow color table.

black - if true the table will also contains a black color entry.

white - if true the table will also contains a white color entry.

gray - if true the table will also contains a gray color entry.

generateRainbow

public static java.awt.Color[] generateRainbow(int size,
                               boolean black,
                               boolean white,
                               boolean gray)

Generates a rainbow color table (HSV ramp) of the specified size.

Parameters:

size - the size of the rainbow color table.

black - if true the table will also contains a black color entry.

white - if true the table will also contains a white color entry.

gray - if true the table will also contains a gray color entry.

generateRainbow

public static java.awt.Color[] generateRainbow(int size)

Generates a rainbow color table (HSV ramp) of the specified size.

Parameters:

size - the size of the HSV color table.

toString

public static java.lang.String toString(java.awt.Color color)

Get String representation of the specified color.

Default representation is "A:R:G:B" where :
A = alpha level in hexadecimal (0x00-0xFF)
R = red level in hexadecimal (0x00-0xFF)
G = green level in hexadecimal (0x00-0xFF)
B = blue level in hexadecimal (0x00-0xFF)

Parameters:

color -

toString

public static java.lang.String toString(int rgb)

Get String representation of the specified rgb value.

Default representation is "A:R:G:B" where :
A = alpha level in hexadecimal (00-FF)
R = red level in hexadecimal (00-FF)
G = green level in hexadecimal (00-FF)
B = blue level in hexadecimal (00-FF)

Parameters:

rgb -

toString

public static java.lang.String toString(java.awt.Color color,
                        boolean hexa)

Get String representation of the specified Color value.

Default representation is "A:R:G:B" where :
A = alpha level
R = red level
G = green level
B = blue level

Parameters:

color -

hexa - component level are represented in hexadecimal (2 digits)

toString

public static java.lang.String toString(int rgb,
                        boolean hexa)

Get String representation of the specified rgb value.

Default representation is "A:R:G:B" where :
A = alpha level
R = red level
G = green level
B = blue level

Parameters:

rgb -

hexa - component level are represented in hexadecimal (2 digits)

toString

public static java.lang.String toString(java.awt.Color color,
                        boolean hexa,
                        java.lang.String sep)

Get String representation of the specified color.

Default representation is "AsepRsepGsepB" where :
A = alpha level in hexadecimal (0x00-0xFF)
R = red level in hexadecimal (0x00-0xFF)
G = green level in hexadecimal (0x00-0xFF)
B = blue level in hexadecimal (0x00-0xFF)
sep = the specified separator

Ex : toString(Color.red, true, ":") --> "FF:FF:00:00"

Parameters:

color -

hexa - component level are represented in hexadecimal (2 digits)

toString

public static java.lang.String toString(int rgb,
                        boolean hexa,
                        java.lang.String sep)

Get String representation of the specified rgb value.

Default representation is "AsepRsepGsepB" where :
A = alpha level in hexadecimal (0x00-0xFF)
R = red level in hexadecimal (0x00-0xFF)
G = green level in hexadecimal (0x00-0xFF)
B = blue level in hexadecimal (0x00-0xFF)
sep = the specified separator

Ex : toString(0xFF00FF00, true, ":") --> "FF:00:FF:00"

Parameters:

rgb -

hexa - component level are represented in hexadecimal (2 digits)

isBlack

public static boolean isBlack(java.awt.Color color)

Returns true if the specified color is pure black (alpha is not verified)

mixOver

public static java.awt.Color mixOver(java.awt.Color backColor,
                     java.awt.Color frontColor)

Mix 2 colors with priority color

mix

public static java.awt.Color mix(java.awt.Color c1,
                 java.awt.Color c2,
                 float ratio)

Mix 2 colors using the following ratio for mixing:
0f means 100% of color 1 and 0% of color 2
0.5f means 50% of color 1 and 50% of color 2
1f means 0% of color 1 and 100% of color 2

mix

public static java.awt.Color mix(java.awt.Color c1,
                 java.awt.Color c2,
                 boolean useAlpha)

Mix 2 colors without "priority" color

mix

public static java.awt.Color mix(java.awt.Color c1,
                 java.awt.Color c2)

Mix 2 colors (no alpha)

add

public static java.awt.Color add(java.awt.Color c1,
                 java.awt.Color c2,
                 boolean useAlpha)

Add 2 colors

add

public static java.awt.Color add(java.awt.Color c1,
                 java.awt.Color c2)

Add 2 colors

sub

public static java.awt.Color sub(java.awt.Color c1,
                 java.awt.Color c2,
                 boolean useAlpha)

Sub 2 colors

sub

public static java.awt.Color sub(java.awt.Color c1,
                 java.awt.Color c2)

Subtract 2 colors

xor

public static java.awt.Color xor(java.awt.Color c)

Get opposite (XORed) color

getGrayMix

public static int getGrayMix(java.awt.Color c)

get to gray level (simple RGB mix)

getGrayMix

public static int getGrayMix(int rgb)

get to gray level (simple RGB mix)

getGrayColorMix

public static java.awt.Color getGrayColorMix(java.awt.Color c)

Convert to gray level color (simple RGB mix)

getGrayColorLum

public static java.awt.Color getGrayColorLum(java.awt.Color c)

Convert to gray level color (from luminance calculation)

getLuminance

public static int getLuminance(java.awt.Color c)

Return luminance (in [0..255] range)

toHSV

public static float[] toHSV(java.awt.Color c)

Convert the specified color to HSV color.

toHSV

public static float[] toHSV(float[] rgb)

Convert the specified RGB color to HSV color.

fromHSV

public static float[] fromHSV(float[] hsv)

Convert the specified HSV color to RGB color.

fromXYZ

public static float[] fromXYZ(float[] xyz)

Convert the specified XYZ color to RGB color.

toXYZ

public static float[] toXYZ(java.awt.Color c)

Convert the specified color to XYZ color.

toXYZ

public static float[] toXYZ(float[] rgb)

Convert the specified RGB color to XYZ color.

toLAB

public static float[] toLAB(java.awt.Color c)

Convert the specified color to LAB color.

toLAB

public static float[] toLAB(float[] rgb)

Convert the specified RGB color to LAB color.

XYZtoLAB

public static float[] XYZtoLAB(float[] xyz)

Convert the specified XYZ color to LAB color.

getDistance

public static double getDistance(java.awt.Color c1,
                 java.awt.Color c2,
                 boolean hsv)

Compute and returns the distance between the 2 colors.
The HSV distance returns a value between 0 and 1 where 1 is maximum distance.
The LAB distance returns a positive value where > 2.3 value is considered a significant distance.

Parameters:

c1 - first color

c2 - second color

hsv - If set to true we use the HSV color space to compute the color distance otherwise we use the LAB color space.

getDominantColor

public static java.awt.Color getDominantColor(java.awt.Color[] colors)

Returns the dominant color from the specified color array.
The dominant color is calculated by computing the color histogram from a rainbow gradient and returning the highest bin number.

getDominantColor

public static java.awt.Color getDominantColor(java.awt.Color[] colors,
                              int binNumber)

Returns the dominant color from the specified color array.
The dominant color is calculated by computing the color histogram from a rainbow gradient and returning the color corresponding to the highest bin.

Parameters:

colors - Color array we want to retrieve the dominant color from.

binNumber - the number of bin to construct the rainbow gradient.

getColorFromWavelength

public static java.awt.Color getColorFromWavelength(double wavelength)

Converts a wavelength into a Color object.
Taken from Earl F. Glynn's web page: Spectra Lab Report

Parameters:

wavelength - the wavelength to convert (in nanometers)

Returns:

a Color object representing the specified wavelength