Java - Image Rotation

问题

I am trying to rotate image. I am using this Java code:

BufferedImage oldImage = ImageIO.read(new FileInputStream("C:\\workspace\\test\\src\\10.JPG"));
BufferedImage newImage = new BufferedImage(oldImage.getHeight(), oldImage.getWidth(), oldImage.getType());
Graphics2D graphics = (Graphics2D) newImage.getGraphics();
graphics.rotate(Math.toRadians(90), newImage.getWidth() / 2, newImage.getHeight() / 2);
graphics.drawImage(oldImage, 0, 0, oldImage.getWidth(), oldImage.getHeight(), null);
ImageIO.write(newImage, "JPG", new FileOutputStream("C:\\workspace\\test\\src\\10_.JPG"));

But I see strange result:

Source:

Result:

Can you please help me with this problem?

回答1:

It is not enough to switch the width and height of the image. You are rotating using the center of the image as the origin of rotation. Just try the same with a sheet of paper and you will see it works the same way. You must also move the paper a little bit, which means to apply a transform to fix this. So, immediately after the rotate call, do this:

  graphics.translate((newImage.getWidth() - oldImage.getWidth()) / 2, (newImage.getHeight() - oldImage.getHeight()) / 2);

回答2:

The new image has different sizes because of the rotate. try this: BufferedImage newImage = new BufferedImage( oldImage.getWidth(),oldImage.getHeight(),oldImage.getType());

回答3:

Try getting bounds of your panel on which you do your drawing

Rectangle rect = this.getBounds();

And then do:

graphics.rotate(Math.toRadians(90), (rect.width - newImage.getWidth()) / 2, (rect.height - newImage.getHeight()) / 2);

Hope that could help Cheers!

回答4:

You can write like this it will be work.

BufferedImage newImage = new BufferedImage(oldImage.getWidth(), oldImage.getHeight(), oldImage.getType());

I think the place for width and height is wrong in your code.

来源：https://stackoverflow.com/questions/12165977/java-image-rotation