Sikuli :-

public class Gmail_Upload

{
    public WebDriver driver;
    public Screen s;

@Test // SIKULI SCRIPT for  upload file
public void FileAttachement() throws Exception

{
driver.get("http://seleniumsubbu.blogspot.in/");
driver.findElement(By.id("edit-submitted-uploadfile-upload")).click();
s.click("/home/chinna/lib/Sikuli/techlearn.in.png");        // (Or) s.click("Image")
driver.findElement(By.id("edit-submitted-uploadfile-upload-button--4")).click();
}
@BeforeTest
 public void beforeTest()

{
driver=new FirefoxDriver();
 s=new Screen();
}