CODEWITHSUNDEEP
javaandroid
jan
jan

Reputation: 61

How to get average RGB value of Bitmap on Android?

I know how to get the RGB values of individual pixels of a bitmap. How can I get the average RGB value for all of the pixels of a bitmap?

Upvotes: 3

Views: 8590

Answers (3)

Sakthivel Appavu
Sakthivel Appavu

Reputation: 575

I think below code for exact answer to you. Get the Average(Number of pixels)of Red, Green and Blue value for the given bitmap. 

Bitmap bitmap = someBitmap; //assign your bitmap here
int redColors = 0;
int greenColors = 0;
int blueColors = 0;
int pixelCount = 0;

for (int y = 0; y < bitmap.getHeight(); y++)
{
    for (int x = 0; x < bitmap.getWidth(); x++)
    {
        int c = bitmap.getPixel(x, y);
        pixelCount++;
        redColors += Color.red(c);
        greenColors += Color.green(c);
        blueColors += Color.blue(c);
    }
}
// calculate average of bitmap r,g,b values
int red = (redColors/pixelCount);
int green = (greenColors/pixelCount);
int blue = (blueColors/pixelCount);

Upvotes: 11

Blackbelt
Blackbelt

Reputation: 157437

you can use this method for this purpose: Bitmap.createBitmap

For instance:

int[] colors = new int[yourWidth * yourHeight];
Arrays.fill(colors, Color.Black);
Bitmap bitamp = Bitamp.createBitmap(colors, yourWidth, yourHeight, Bitmap.Config.ARGB_8888);

Check for typo

Upvotes: 1

Jared Rummler
Jared Rummler

Reputation: 38121

The answer from john sakthi does not work correctly if the Bitmap has transparency (PNGs). I modified the answer for correctly getting the red/green/blue averages while accounting for transparent pixels:

/**
 * Calculate the average red, green, blue color values of a bitmap
 *
 * @param bitmap
 *            a {@link Bitmap}
 * @return
 */
public static int[] getAverageColorRGB(Bitmap bitmap) {
    final int width = bitmap.getWidth();
    final int height = bitmap.getHeight();
    int size = width * height;
    int pixelColor;
    int r, g, b;
    r = g = b = 0;
    for (int x = 0; x < width; ++x) {
        for (int y = 0; y < height; ++y) {
            pixelColor = bitmap.getPixel(x, y);
            if (pixelColor == 0) {
                size--;
                continue;
            }
            r += Color.red(pixelColor);
            g += Color.green(pixelColor);
            b += Color.blue(pixelColor);
        }
    }
    r /= size;
    g /= size;
    b /= size;
    return new int[] {
            r, g, b
    };
}

Upvotes: 2

Related Questions