Points on an Image

[colin shuker]

Supposing I have drawn a picture in a frame with paintComponent
method, and then saved this as an Image. Then suppose I chose the point
(100,100) on the image, is it possible to determine the colour of this
point??

Basically, I am constructing a breakout game. I have it working, but
there are too many if statements to go through to check if the ball has
hit the bricks, and in which way. If I could test the colour of some points around the edge of the ball, I could determine if it was about to hit a brick or not.

Any help is appreciated, thanks

[colin shuker]

Ahh, I just read a post below, someone amazingly had the same problem.
I need to use the getRGB() method on a BufferedImage object. Just checking
the API now.
Any hints/tips are welcomed. Thanks

[colin shuker]

OK, I've got it working kind of.
I'm using a BufferedImage object declared by:

BufferedImage pic=new BufferedImage(509,660, BufferedImage.TYPE_INT_RGB);

Now, when I use getRBG(x,y) over part of the image that is green, it returns -16711936
For blue, it returns -16776961
For black, it returns -16777216 (=-256*256*256)
For white, it returns -1

Usually when I create a Color using new Color(r,b,g)
I find that (0,0,0) is black, (255,255,255) is white and so on..
Can anyone explain the link between these different values.
Thanks

[Craig Wood]

Check the PixelGrabber api, first block of code in the discussion section. The 'int' returned by 'getRGB' is the 'pixel' variable in that block.

[Ed Ewing]

Try something like this:

int red = (rgb >> 16) & 0xFF;
int green = (rgb >> 8) & 0xFF;
int blue = rgb & 0xFF;

Or you can create a new Color object:

Color c = new Color(rgb);
int red = c.getRed();