how to create an emoji image with graphics2d and google noto color font - graphics2d

Question

I wrote a java program to render an emoji and create a local image file with it. To do that I downloaded Google's "Noto Color Emoji" font from google website.
This is mi code:
package com.test;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
public class Test {
public static void main(String[] args) throws IOException {
String string = "😄";
BufferedImage image;
Font font = null;
try {
font = Font.createFont(Font.TRUETYPE_FONT, new FileInputStream("/home/sandra/.fonts/NotoColorEmoji.ttf"));
} catch (FontFormatException e) {
e.printStackTrace();
}
image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = image.createGraphics();
g2.setFont(font);
g2.drawString(string, 0, g2.getFontMetrics().getAscent());
g2.dispose();
File f = new File("image.png");
if (!f.exists()) {
if (!f.createNewFile()) {
System.err.println("Can't create image file.");
}
}
try {
ImageIO.write(image, "png", f);
} catch (IOException e) {
e.printStackTrace();
}
}
}
I tried to run it in both mac and linux (ubuntu) and the output in both cases is a black square.
Am I missing anything obvious? I also tried these commands mentioned at the end of this post (https://github.com/notwaldorf/ama/issues/53) but there is no difference on the output image.
I would appreciate any help on this as I'm quite new on emoji display.
Thanks in advance,
Sandra

Answer 1

Change:
image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
to:
image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB);
It needs TYPE_INT_ARGB.
And add this before drawString():
g2.setPaint(Color.WHITE)