BufferedImage TYPE_CUSTOM to TYPE_INT_ARGB

[Arron Ferguson]

Hey all,

I'm trying to load a PNG image in that has transparency in it using JDK 1.6 u10 and manipulate the image data (pixels). The problem is if I do this:

BufferedImage bi = null;
try {
    bi = ImageIO.read(new File("test.png"));
} catch (Exception e) {
    e.printStackTrace();
}
System.out.println(bi.getType()); // == 0

Or this:

BufferedImage bi = toBufferedImage(Toolkit.getDefaultToolkit().createImage("test.png"));
System.out.println(original.getType()); // == 0

Or this:

Image image = new ImageIcon("test.png").getImage();
bi = new BufferedImage(image.getWidth(null), image.getHeight(null), type);
Graphics g = bimage.createGraphics();
g.drawImage(image, 0, 0, null);
g.dispose();
System.out.println(original.getType()); // == 0

The type is always TYPE_CUSTOM and not TYPE_INT_ARGB - which seems odd because the PNG file that I am loading has transparency in it.

What I want is the BufferedImage (which has the PNG image data I'm interested in) so that I can play with the image data (e.g. perform a projective transformation) :

int w = 100;
int h = 100;
int[] pixels = new int[w * h];
// do something interesting with pixel data which, if it is ARGB, I can access pixel values
// like this:
// int pixelColor =
//     ((alphaChannel << 24) | (redChannel << 16) | (greenChannel << 8) | blueChannel);
// where the channel values are somehow/somewhere calculated
WritableRaster wr = bi.getRaster().setDataElements (0, 0, w, h, pixels);

Any advice would be greatly appreciated!

[Arron Ferguson]

Here's the funny thing ...

I tried this:

int w = 70;
int h = 70;
BufferedImage bi = toBufferedImage(image);
WritableRaster wr = bi.getRaster();
int[] pixels = new int[w * h];
pixels[321] = ((255 << 24) | (0 << 16) | (0 << 8) | 0);

And it drew a black pixel ... which means that it is in fact TYPE_INT_ARGB not TYPE_CUSTOM. Funny those Sun engineers wouldn't call it what it is but treat it as it is.

[Arron Ferguson]

Okay this is the last post from me in this thread - I just figured I would share so as to help anyone else from making the same mistake. The PNG with transparency is correctly set to TYPE_INT_ARGB (i.e. with alpha). What I did wrong (and it was my fault), was that I made the following instance method call in the class GraphicsConfiguration:

gc.createCompatibleImage(w, h, Transparency.BITMASK);

This resulted in being considered a "TYPE_CUSTOM " BufferedImage. As soon as I said:

gc.createCompatibleImage(w, h, Transparency.TRANSLUCENT);

The BufferedImage.getType returned TYPE_INT_ARGB (== 2)

Sorry for all the posts.