ImageIO Pixel Example

import org.apache.commons.lang3.StringUtils;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by david on 12/17/14
 */
public class Main
{
    public static void main(String[] args) throws IOException
    {
        BufferedImage bufferedImage = ImageIO.read(Main.class.getResource("/annalisa-licciardi.png"));
        int[][][] result = getPixels(bufferedImage);
        for(int i = 0; i < result.length; i++)
        {
            for(int j = 0; j < result[i].length; j++)
            {
                System.out.println(i + " " + j + " " + intArrayToString(result[i][j]));
            }
        }
    }

    private static String intArrayToString(int[] integers)
    {
        List<String> output = new ArrayList<>();
        for(int i = 0; i < integers.length; i ++)
            output.add(Integer.toString(integers[i]));
        return StringUtils.join(output, ",");
    }


    private static int[][][] getPixels(BufferedImage image) {

        final byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
        final int width = image.getWidth();
        final int height = image.getHeight();
        final boolean hasAlphaChannel = image.getAlphaRaster() != null;

        int[][][] result = new int[height][width][4];

        if (hasAlphaChannel) {
            final int pixelLength = 4;
            for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
                int[] pixelData = new int[4];
                pixelData[0] = (int) pixels[pixel] & 0xff;
                pixelData[1] = (int) pixels[pixel + 1] & 0xff;
                pixelData[2] = (int) pixels[pixel + 2] & 0xff;
                pixelData[3] = (int) pixels[pixel + 3] & 0xff;
                result[row][col] = pixelData;

                /*
                int argb = 0;
                argb += (((int) pixels[pixel] & 0xff) << 24); // alpha
                argb += ((int) pixels[pixel + 1] & 0xff); // blue
                argb += (((int) pixels[pixel + 2] & 0xff) << 8); // green
                argb += (((int) pixels[pixel + 3] & 0xff) << 16); // red
                result[row][col] = argb;
                col++;
                if (col == width) {
                    col = 0;
                    row++;
                }
                */
            }
        } else {
            final int pixelLength = 3;
            for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
                int[] pixelData = new int[4];
                pixelData[0] = 0;
                pixelData[1] = (int) pixels[pixel] & 0xff;
                pixelData[2] = (int) pixels[pixel + 1] & 0xff;
                pixelData[3] = (int) pixels[pixel + 2] & 0xff;
                result[row][col] = pixelData;

                /*
                int argb = 0;
                argb += -16777216; // 255 alpha
                argb += ((int) pixels[pixel] & 0xff); // blue
                argb += (((int) pixels[pixel + 1] & 0xff) << 8); // green
                argb += (((int) pixels[pixel + 2] & 0xff) << 16); // red
                result[row][col] = argb;
                col++;
                if (col == width) {
                    col = 0;
                    row++;
                }
                */
            }
        }

        return result;
    }

}