Question

I am using an Applet to save image from clipboard. The image is saved but something happened with its format. It is darken and lost colors.

here’s how I am doing it:

AccessController.doPrivileged(new PrivilegedAction() {
    public Object run() {

        try {
            //create clipboard object
            Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
            //Get data from clipboard and assign it to an image.
            //clipboard.getData() returns an object, so we need to cast it to a BufferdImage.
            BufferedImage image = (BufferedImage) clipboard.getData(DataFlavor.imageFlavor);
            //file that we'll save to disk.
            File file = new File("/tmp/clipboard.jpg");
            //class to write image to disk.  You specify the image to be saved, its type,
            // and then the file in which to write the image data.
            ImageIO.write(image, "jpg", file);
            //getData throws this.
        } catch (UnsupportedFlavorException ufe) {
            ufe.printStackTrace();
            return "Não tem imagem na área de transferência";
        } catch (Exception ioe){
            ioe.printStackTrace();
        }
        return null;
    }
}

);

I read that Mac uses a different image format but I did not find how to convert it to a format I could save. I imagined that java should have taken care of that.

So, how can I convert the image from clipboard to jpg?

PS. I tried using png instead of jpg, got a worse result: black image

Answer 1

To solve the issue on Mac, I used the solution proposed on The nightmares of getting images from the Mac OS X clipboard using Java.

I pass the retrieved BufferedImage to method that redraws it to new BufferedImage, returning a valid image. Here follows the code from that page:

public static BufferedImage getBufferedImage(Image img) {
        if (img == null) return null;
        int w = img.getWidth(null);
        int h = img.getHeight(null);
        // draw original image to thumbnail image object and
        // scale it to the new size on-the-fly
        BufferedImage bufimg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = bufimg.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        g2.drawImage(img, 0, 0, w, h, null);
        g2.dispose();
        return bufimg;
    }

And how I use it:

Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
//Get data from clipboard and assign it to an image.
//clipboard.getData() returns an object, so we need to cast it to a BufferdImage.
BufferedImage image = (BufferedImage) clipboard.getData(DataFlavor.imageFlavor);

if (isMac()) {
    image = getBufferedImage(image);
}