How to clone Image?

Question

I have an Image. I need to make a exactly copy of it and save it to BufferedImage, but there is no Image.clone(). The thing should be inside a calculating loop and so it should be really fast, no pixel-by-pixel copying. What's the best in perfomance method to do this?

Masaryk

Take a look at this #3514658 – Swede

It copies Image pixel-by-pixel (just copies the raster data). Is there any way to do it faster? – Masaryk

If you want a deep copy, there is no other way I know about. And why do you want to clone it every loop iteration? – Swede

Actually I need to make a lot of image copies which is rotated by 1 degree, so I need to copy basic image and perform some operations on it. – Masaryk

Answer 1

You can draw to a buffered image, so make a blank bufferedImage, create a graphics context from it, and draw your original image to it.

BufferedImage copyOfImage = 
   new BufferedImage(widthOfImage, heightOfImage, BufferedImage.TYPE_INT_RGB);
Graphics g = copyOfImage.createGraphics();
g.drawImage(originalImage, 0, 0, null);

Mythopoeia

That would lose transparency. If in doubt, use TYPE_INT_ARGB. – Irksome

Hm... This looks faster for me. – Masaryk

Always remember to dispose() the Graphics object after use! – Rogation

Answer 2

There is another way:

BufferedImage copyOfImage = image.getSubimage(0, 0, image.getWidth, image.getHeight);

Eligibility

No, this won't work, as copyOfImage and image will share backing buffers (it will be a shallow copy). Edits made to one, will be reflected in the other. – Rogation

Answer 3

Image clone = original.getScaledInstance(original.getWidth(), -1, Image.SCALE_DEFAULT);

This might not be very pretty, but getScaledInstance returns, as the name suggests, an instance of your original Image object. Usually only used for resizing. -1 tells the method to keep the aspect ratio as it is

Keelboat

Could you please edit your answer to give an explanation of why this code answers the question? Code-only answers are discouraged, because they don't teach the solution. – Radioluminescence

Answer 4

You can create a method that returns the subimage of the image you want to clone.

Such as:

public static BufferedImage clone(BufferedImage img)
{
  return img.getSubimage(img.getMinX(), img.getMinY(), img.getWidth(), img.getHeight());
}

Bernat