A small Java program to generate transparent images (for dynamic background colours)

2012-04-29 A small Java program to generate transparent images (for dynamic background colours)

Somebody requested me to generate a web page with a wall background that should change the wall colour based on the user's desire.
I thought a transparency-enabled background will suffice, with a dynamic background of the image.
Steps:

Take the background image from my customer;
Generate a mask image as a copy of the background image, and remove the area (set it to black) where I want to have transparency;
Run the Java program that is written below;
Use the final result image and put it in a web page.

You can check the result (while the web page is still there) at: http://dev-alexandru-doors.sorescu.eu/products-en_GB where you may click any image from gallery and the background image will appear.

ImageTansparency.java

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class ImageTransparency {
	private static BufferedImage original;
	private static BufferedImage mask;
	private static BufferedImage result;

	public static void main(String[] args) throws IOException {
		String folder = "C:\\Users\\DragosMateiS\\Desktop\\";
		original = ImageIO.read(new File(folder + "wall test image.jpg"));
		mask = ImageIO.read(new File(folder + "wall test image - mask.jpg"));
		result = new BufferedImage(original.getWidth(), original.getHeight(),
				BufferedImage.TYPE_INT_ARGB);
		process();
		ImageIO.write(result, "png", new File(folder
				+ "wall test image - result.png"));
	}

	private static void process() {
		int width = original.getWidth();
		int height = original.getHeight();
		for (int x = 0; x < width; x++)
			for (int y = 0; y < height; y++) {
				Color originalRGB = new Color(original.getRGB(x, y));
				Color maskRGB = new Color(mask.getRGB(x, y));
				int argb = originalRGB.getRGB();
				int r = maskRGB.getRed();
				int g = maskRGB.getGreen();
				int b = maskRGB.getBlue();
				int balance = r * 2 + b + g * 4;
				int alpha=balance/7;
				if (alpha >= 30) 
					argb &= 0x00ffffff + (alpha << 24);
				result.setRGB(x, y, argb);
			}
	}
}