BufferedImage rotated, change resulting background

Question

When I rotate an image using Graphics2D.rotate() obviously it leaves some empty space in the corners. The empty corners become transparents.

I want my program to rotate the BufferedImage and to fill the remaining empty corners with a white color.

How do I do this?

In other words, I want to rotate the image while preserving a white background for the whole image.

This is my function:

public BufferedImage rotateImage(BufferedImage image, double degreesAngle) {    
        int w = image.getWidth();    
        int h = image.getHeight();    
        BufferedImage result = new BufferedImage(w, h, image.getType());  
        Graphics2D g2 = result.createGraphics();  
        g2.rotate(Math.toRadians(degreesAngle), w/2, h/2);
        g2.drawImage(image,null,0,0);  
        return result;   
    }

I then use this image to paint it a transparent JPanel, which I later add to a JLayeredPane.

However, my image has transparent corners and I want to fill them with a white color.

This depends, on what are you rotating the image? `JComponent`? `JPanel`? How are you rotating the image...an example would be nice... — MadProgrammer, Nov 28 '13 at 01:31
I rotate the image independently and save it as a BufferedImage, which I later paint onto a JPanel. — ThePrince, Nov 28 '13 at 01:38

score 4 · Accepted Answer · answered Nov 28 '13 at 01:47

You have (at least) two options...

You Could...

Paint the background of the BufferedImage before you paint the rotated image...

public BufferedImage rotateImage(BufferedImage image, double degreesAngle) {    
    int w = image.getWidth();    
    int h = image.getHeight();    
    BufferedImage result = new BufferedImage(w, h, image.getType());  
    Graphics2D g2 = result.createGraphics();  
    g2.setColor(Color.WHITE);
    g2.fillRect(0, 0, w, h);
    g2.rotate(Math.toRadians(degreesAngle), w/2, h/2);
    g2.drawImage(image,null,0,0);  
    return result;   
}

You Could...

Paint the area behind the image before you paint it to the panel...

@ThePrince Well that makes a nice change ;) – MadProgrammer Nov 28 '13 at 02:16 — MadProgrammer, Nov 28 '13 at 02:16

BufferedImage rotated, change resulting background

1 Answers1

You Could...

You Could...

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