Test.java

import com.google.zxing.Binarizer;
import com.google.zxing.LuminanceSource;
import com.google.zxing.RGBLuminanceSource;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import java.io.InputStream;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import java.awt.image.WritableRaster;
import java.awt.image.DataBufferByte;
import java.io.ByteArrayInputStream;

public class Test {
    public static void main( String[] args ) {
        File imgPath = new File( args[0] );
        try {
            BufferedImage bufferedImage = ImageIO.read(imgPath);
            byte[] pixels = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();

            LuminanceSource source = new RGBLuminanceSource(bufferedImage.getWidth(), bufferedImage.getHeight(), getPixelArray(bufferedImage));

            BinaryBitmap bitmap = new BinaryBitmap( new HybridBinarizer( source ));
            BitMatrix bitMatrix = bitmap.getBlackMatrix();

            for (int row=0; row<bitMatrix.getHeight(); row++) {
                for (int col=0; col<bitMatrix.getWidth(); col++) {
                    for (int channels=0; channels<3; channels++) {
                        int idx = (col + bitMatrix.getWidth() * row)*3 + channels;
                        if (bitMatrix.get(col, row)) {
                            pixels[idx] = 0;
                        } else {
                            pixels[idx] = -1;
                        }
                    }
                }
            }

            ImageIO.write(bufferedImage, "jpg", new File("binary_output.jpg"));

        } catch (Throwable t) {
            System.out.println(t.getMessage());
        }
    }

    private static int[] getPixelArray(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];
        if (hasAlphaChannel) {
            final int pixelLength = 4;
            for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
                int idx = col + row*width;
                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[idx] = 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 argb = 0;
                int idx = col + row*width;
                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[idx] = argb;
                col++;
                if (col == width) {
                    col = 0;
                    row++;
                }
            }
        }

        return result;
    }
}