Java Color conversion

Question

I am having a problem using a method from com.esri.arcgis.display.IColor. The method is IColor.getRGB() which returns an int.

IColor symbolColor = symbol.getColor();
int colorInt = symbolColor.getRGB();
//TODO: get RGB values from colorInt

From the documentation:

RGB returns the Long (ASCII) number calculated from the Red, Green and Blue color attributes.

I need to get the individual RGB values (standard 0-255) from this int somehow but I have been unable to find almost any information on converting from an ASCII number to RGB values.

Possible duplicate of [Bit Shift and Bitwise operations to encode RGB values](http://stackoverflow.com/questions/19277010/bit-shift-and-bitwise-operations-to-encode-rgb-values) — Andy Turner, Oct 14 '15 at 22:26
An int is an int is an int. You might look at `colorInt` formatted as a decimal, say _10760562_, and it seems to make no sense as an RGB value, but if you format and print it as a hex value it will be `0xRRGGBB` — _10760562 == 0xA43172_, which clearly contains the individual red, green, and blue values. — Stephen P, Oct 14 '15 at 23:50

score 0 · Accepted Answer · edited Oct 14 '15 at 22:35

0

Have solved by converting the int to hex, and then decoding the hex string using Color.decode() to obtain a Color. Using Color instance we can grab the individual RGB values.

IColor symbolColor = symbol.getColor();
int colorInt = symbolColor.getRGB();
String hexColor = Integer.toHexString(colorInt);
Color color = Color.decode("#"+hexColor);
int red = color.getRed();
int blue = color.getBlue();
int green = color.getGreen();
int alpha = color.getAlpha();`

edited Oct 14 '15 at 22:35

Kamran Ali

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answered Oct 14 '15 at 22:30

GregH

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This inefficient because you needlessly convert to String and back. – randers Oct 14 '15 at 23:57

score -1 · Answer 2 · answered Oct 14 '15 at 22:42

-1

It is possible to convert these values by transferring their RGB integer.

int rgb = symbol.getColor().getRGB();
Color color = new Color(rgb);
int red = color.getRed();
int blue = color.getBlue();
int green = color.getGreen();
int alpha = color.getAlpha();

You might need to further investigate wether that rgb variable also contains the alpha values, in which case you want to use new Color(rgb, true) instead.

answered Oct 14 '15 at 22:42

randers

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Using bit & operation and shift would be more straightforward and faster as shown by Andy Turner's link. – dragon66 Oct 14 '15 at 22:48
@dragon66 I would personally prefer a library usage over bitwise operations because I find them very unreadable. That's why I answered with this possibility. – randers Oct 14 '15 at 22:50

Java Color conversion

2 Answers2