Corrected the handling of transparent versus opaque images.

Corrected the handling of transparent versus opaque images.

Different image types are selected, depending on whether an image is opaque
or has transparency.  This fixes transparent image handling
(where the transparency was sometimes removed) as well as BGR image handling
(these came out with weird colors).

Improvements to the image rewriting:
o Changed the transparent color writing method
o Corrected a bug with isResizeRequired()
o Allows accurate handling of images with embedded transparency.

[Paul Lindner, 2009-06-18 21:06:42]

lgtm

[louiscryan, 2009-06-18 21:32:26]

Looks good

[chirag, 2009-06-18 22:23:06]

http://codereview.appspot.com/79045/diff/1/2
File
java/gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/image/BasicImageRewriter.java
(right):

http://codereview.appspot.com/79045/diff/1/2#newcode302
Line 302: g2d.setComposite(AlphaComposite.Clear);
I'm a bit confused about this.

Is there a reason why the composite is being set to AlphaComposite.Clear, even
though it's being set to AlphaComposite.SrcOver a few lines down?

http://codereview.appspot.com/79045/diff/1/2#newcode305
Line 305: g2d.setComposite(AlphaComposite.SrcOver);
I'm curious about this.

I know AlphaComposite.Src will preserve alpha channels by only writing the
source image into the buffer.

What's the benefit of using AlphaComposite.SrcOver instead of
AlphaComposite.Src?