这应该工作：

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

import javax.imageio.ImageIO;

import org.openqa.selenium.By;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.Point;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriver;

public class Shooter{

    private WebDriver driver;

    public void shootWebElement(WebElement element) throws IOException  {

        File screen = ((TakesScreenshot) this.driver).getScreenshotAs(OutputType.FILE);

        Point p = element.getLocation();

        int width = element.getSize().getWidth();
        int height = element.getSize().getHeight();

        BufferedImage img = ImageIO.read(screen);

        BufferedImage dest = img.getSubimage(p.getX(), p.getY(), width,   
                                 height);

        ImageIO.write(dest, "png", screen);

        File f = new File("S:\\ome\\where\\over\\the\\rainbow");

        FileUtils.copyFile(screen, f);

    }
}