Getting RGB color from image in Android

Question

I'm making a game and in the game I load the map using an image. I check each pixel RGB and depends on that I add objects. This is my code:

        private void loadLevel() {
    Bitmap image = Assets.loadLevel(LEVEL);
    int w = image.getWidth();
    int h = image.getHeight();
    for (int xx = 0; xx < h; xx++) {
        for (int yy = 0; yy < w; yy++) {
            int pixel = image.getPixel(xx, yy);
            int red = (pixel >> 16) & 0xff;
            int green = (pixel >> 8) & 0xff;
            int blue = (pixel) & 0xff;

            if (red == 100 && green == 60 && blue == 0) { // / block
                Log.d("PlayState","Creating blockss!!!");
                addObject(new Block(xx * 32, yy * 32, 0, ObjectId.Block));

            }
            if (red == 100 && green == 50 && blue == 0) { // /block 1
                addObject(new Block(xx * 32, yy * 32, 1, ObjectId.Block));
            }
            if (red == 100 && green == 40 && blue == 0) { // /block 2
                addObject(new Block(xx * 32, yy * 32, 2, ObjectId.Block));
            }
            if (red == 100 && green == 30 && blue == 0) { // /block 3
                addObject(new Block(xx * 32, yy * 32, 3, ObjectId.Block));
            }
            if (red == 255 && green == 255 && blue == 255) { // /block 4
                addObject(new Block(xx * 32, yy * 32, 4, ObjectId.Block));
            }
            if (red == 255 && green == 255 && blue == 245) { // /block 5
                addObject(new Block(xx * 32, yy * 32, 7, ObjectId.Block));
            }
            if (red == 0 && green == 255 && blue == 33) { // /block up
                addObject(new Block(xx * 32, yy * 32, 5, ObjectId.Block));
            }
            if (red == 0 && green == 245 && blue == 33) { // /block up1
                addObject(new Block(xx * 32, yy * 32, 6, ObjectId.Block));
            }
            if (red == 0 && green == 0 && blue == 255) { // / player
                Log.d("PlayState","Creating Playerrr!!!");
                addObject(new Player(xx * 32, yy * 32, ObjectId.Player));

            }
        }
    }

}

The problem is that for some reason it only adds the Player object,it might be becuase it is the only object that both red & green are 0. When I used exactly the same code to program to windows it worked great.

Btw, I have also tried

            int red = Color.red(pixel);
            int green = Color.green(pixel);
            int blue = Color.blue(pixel);

same result...

EDIT:

If someone else has this problem thanks to @JASONGPETERSON I found the solution. Instead of looking for the exact value check if it a bit lower or higher, for example

if ((red > 90 && red < 110) && (green > 50 && green < 70) && blue == 0) { // / block
                Log.d("PlayState","Creating blockss!!!");
                addObject(new Block(xx * 32, yy * 32, 0, ObjectId.Block));

            }

Please, look at this http://stackoverflow.com/questions/5669501/how-to-get-rgb-values-of-bitmap-in-android — JpCrow, Dec 17 '14 at 15:38
Perhaps your conditions need to test for a narrow range instead of an exact integer. There may be some rounding due to the `getPixel()` method, image compression, etc. — JASON G PETERSON, Dec 17 '14 at 15:40
@JASONGPETERSON yey you there right!!! when I checked if the the color is lower or higher by 10 it worked.Thanks alot :)) — Gilmor, Dec 17 '14 at 16:09

score 0 · Answer 1 · answered Dec 17 '14 at 15:36

0

Did you try to Log.d the red, green and blue values to see whether it's really the situation as observed?

answered Dec 17 '14 at 15:36

Patrick Chan

1,019
10
14

score 0 · Answer 2 · answered Dec 17 '14 at 15:44

0

Maybe not fixing your problem but :

int pixel = image.getPixel(xx, yy);

suggest you're using "xx" as "x coordinate" (width) but you're itering on the height of your image with :

int h = image.getHeight();
for (int xx = 0; xx < h; xx++)

answered Dec 17 '14 at 15:44

Nino DELCEY

652
1
9
25

I didnt notice that, but that doesnt matter becuase in the end it will check all the pixels so it will give the same result. – Gilmor Dec 17 '14 at 16:00

score 0 · Accepted Answer · answered Dec 17 '14 at 16:11

0

Perhaps your conditions need to test for a narrow range instead of an exact integer. There may be some rounding due to the getPixel() method, image compression, etc. (And, in fact, this turned out to work.)

answered Dec 17 '14 at 16:11

JASON G PETERSON

2,193
1
18
19

Getting RGB color from image in Android

3 Answers3