旋转后Java2D图像质量下降

Question

I'm using following code for rotate my image

public class Field extends Canvas implements ActionListener {

    @Override
    public void paint(Graphics grphcs) {        
        super.paint(grphcs);         
        Graphics2D g2d = (Graphics2D) grphcs;
        AffineTransform affine = new AffineTransform();
        int angle = car.getAngle();
        Image image = car.getCarImage();       
        int x = (int) car.getX();
        int y = (int) car.getY();

        affine.rotate(Math.toRadians(angle), x + image.getWidth(null) / 2, 
               y + image.getHeight(null) / 2);
        g2d.setTransform(affine); 
        g2d.drawImage(image, x, y, null);     
    }  
    ....

if angle equals, for example, 5 image quality is lost.

What's the problem?

Answer 1

You have to use antialiasing, try this:

g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);

example: the right icon is antialiased http://i.imgur.com/yeJux.png

Answer 2

The other answers are half correct: Your problem can be solved by setting a RenderingHint. But in this case, it's not antialiasing.

Try adding this before you apply your transform:

g2d.setRenderingHint(RenderingHints.KEY_RENDERING,
                     RenderingHints.VALUE_RENDER_QUALITY);