How to convert getRGB(x,y) integer pixel to Color(r,g,b,a) in Java?

Question

I have the integer pixel I got from getRGB(x,y), but I don't have any clue about how to convert it to RGBA format. For example, -16726016 should be Color(0,200,0,255). Any tips?

score 51 · Accepted Answer · edited Jan 06 '19 at 12:39

51

If I'm guessing right, what you get back is an unsigned integer of the form 0xAARRGGBB, so

int b = (argb)&0xFF;
int g = (argb>>8)&0xFF;
int r = (argb>>16)&0xFF;
int a = (argb>>24)&0xFF;

would extract the color components. However, a quick look at the docs says that you can just do

Color c = new Color(argb);

or

Color c = new Color(argb, true);

if you want the alpha component in the Color as well.

UPDATE

Red and Blue components are inverted in original answer, so the right answer will be:

int r = (argb>>16)&0xFF;
int g = (argb>>8)&0xFF;
int b = (argb>>0)&0xFF;

updated also in the first piece of code

edited Jan 06 '19 at 12:39

Bilal

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answered Mar 28 '10 at 19:05

AKX

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@Gevorg: Might be. But that's fairly obvious to notice when testing the code. :) – AKX Dec 08 '11 at 07:53
@AKX Unless you test it with (0,200,0,255)! ;) – Marsellus Wallace Dec 08 '11 at 15:51
3

According to http://docs.oracle.com/javase/7/docs/api/java/awt/Color.html#getRGB%28%29: Bits 24-31 are alpha, 16-23 are red, 8-15 are green, 0-7 are blue – Jack Apr 08 '14 at 23:40

laher · Answer 2 · 2013-08-03T02:45:56.453

28

    Color c = new Color(-16726016, true);
    System.out.println(c.getRed());
    System.out.println(c.getGreen());
    System.out.println(c.getBlue());
    System.out.println(c.getAlpha());

prints out:

Is that what you mean?

edited Aug 03 '13 at 02:45

answered Mar 28 '10 at 19:09

laher

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How to convert getRGB(x,y) integer pixel to Color(r,g,b,a) in Java?

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