ImgToLua.java

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;

import javax.imageio.ImageIO;


public class ImgToLua {
    public static void main(String[] args) throws IOException {
        StringBuilder result = new StringBuilder("local img = {");
        String newLine = ",\n             ";
        BufferedImage img = ImageIO.read(new File("")); // Change this to the file location for the image to convert
        for (int i = 0; i < img.getWidth(); i++) {
            if (i != 0)
                result.append(newLine);
            readLine(img, i, result);
        }
        result.append("}");
        System.out.println(result.toString());
    }

    public static void readLine(BufferedImage src, int row, StringBuilder dest) {
        StringBuilder line = new StringBuilder("{");
        for (int i = 0; i < src.getHeight(); i++) {
            if (i != 0)
                line.append(",");
            line.append(convert(src.getRGB(row, i)));
        }
        line.append("}");
        dest.append(line);
    }

    public static String convert(int rgb) {
        return "0x" + pad(Integer.toHexString(rgb & 0xFFFFFF), 6).toUpperCase();
    }

    public static String pad(String hex, int digits) {
        if (hex.length() >= digits)
            return hex;
        char[] c = new char[digits - hex.length()];
        Arrays.fill(c, '0');
        return new String(c) + hex;
    }
}