Get list of unique MIME types that can be read : ImageIO « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. ImageIO

import java.util.Arrays;

import javax.imageio.ImageIO;

public class Main {
  public static void main(String[] argv) throws Exception {

    String[] formatNames = ImageIO.getReaderMIMETypes();
    System.out.println(Arrays.toString(formatNames));
  }
}