image2buf.html
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<TITLE>Creating a Buffered Image from an Image
(Java Developers Almanac Example)
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<META CONTENT="Patrick Chan" NAME="AUTHOR">
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<B><A HREF="../java.awt.image/pkg.html">java.awt.image</A></B><font color="#666666" SIZE="-2">
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<B><A HREF="../java.awt.image/pkg.html#Buffered%20Images">Buffered Images</A></B><font color="#666666" SIZE="-2">
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<h3>
e671.
Creating a Buffered Image from an Image</h3>
An <code>Image</code> object cannot be converted to a <code>BufferedImage</code>
object. The closest equivalent is to create a buffered image and then
draw the image on the buffered image. This example defines a method
that does this.
<pre>
// This method returns a buffered image with the contents of an image
public static BufferedImage toBufferedImage(Image image) {
if (image instanceof BufferedImage) {
return (BufferedImage)image;
}
// This code ensures that all the pixels in the image are loaded
image = new ImageIcon(image).getImage();
// Determine if the image has transparent pixels; for this method's
// implementation, see <a href="../java.awt.image/HasAlpha.html" class="eglink"><font size="-1"><b>e665</b> Determining If an Image Has Transparent Pixels</font></a>
boolean hasAlpha = <font color="#0066ff"><i>hasAlpha</i></font>(image);
// Create a buffered image with a format that's compatible with the screen
BufferedImage bimage = null;
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
try {
// Determine the type of transparency of the new buffered image
int transparency = Transparency.OPAQUE;
if (hasAlpha) {
transparency = Transparency.BITMASK;
}
// Create the buffered image
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
bimage = gc.createCompatibleImage(
image.getWidth(null), image.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
}
if (bimage == null) {
// Create a buffered image using the default color model
int type = BufferedImage.TYPE_INT_RGB;
if (hasAlpha) {
type = BufferedImage.TYPE_INT_ARGB;
}
bimage = new BufferedImage(image.getWidth(null), image.getHeight(null), type);
}
// Copy image to buffered image
Graphics g = bimage.createGraphics();
// Paint the image onto the buffered image
g.drawImage(image, 0, 0, null);
g.dispose();
return bimage;
}
</pre>
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Related Examples
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e670. <a class="eglink" href="CreateBuf.html?l=rel">
Creating a Buffered Image
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e672. <a class="eglink" href="Mandelbrot2.html?l=rel">
Creating a Buffered Image from an Array of Color-Indexed Pixel Values
</a>
<br>
e673. <a class="eglink" href="DrawOnImage.html?l=rel">
Drawing on a Buffered Image
</a>
<br>
e674. <a class="eglink" href="Buf2Image.html?l=rel">
Converting a Buffered Image to an Image
</a>
<br>
e675. <a class="eglink" href="ImagePixel.html?l=rel">
Getting and Setting Pixels in a Buffered Image
</a>
<br>
e676. <a class="eglink" href="CreateTxImage.html?l=rel">
Scaling, Shearing, Translating, and Rotating a Buffered Image
</a>
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See also:
<a class="eglink" href="/egs/java.awt.image/pkg.html?l=rel#Effects">
Effects
</a>
<a class="eglink" href="/egs/java.awt.image/pkg.html?l=rel#Images">
Images
</a>
<a class="eglink" href="/egs/java.awt.image/pkg.html?l=rel#Volatile%20Images">
Volatile Images
</a>
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