Paul, Thanks for reporting this and pinging back. Sorry your first message got lost in the shuffle.
On Wed, Nov 24, 2010 at 5:50 AM, Paul Robinson <[email protected]> wrote: > No reply on this, so I've just created issue 5651 so it doesn't get lost. > It would be nice if the GWT compiler could produce png image bundles in > compressed format. > > Background: The png file format has support for the deflate algorithm > built-in, but png files don't *have* to use it. So some png files will > contain compressed data, while others will not. GWT with an out-of-the-box > JDK do not generate compressed png files. > > http://code.google.com/p/google-web-toolkit/issues/detail?id=5651 > > Thanks, > Paul > > > On 03/11/10 00:13, Paul Robinson wrote: > > I've just started using this colour picker: > http://code.google.com/p/auroris/wiki/ColorPicker > > One of the warnings its documentation provides is that when you compile it > with GWT, the images it contains are compiled into a png file that is about > 1MB. Whereas, if you then open that file in any image processing software > and re-save it, it compresses down to around 110kb. > > The problem is that during the compile, GWT's ImageBundleBuilder uses > javax.imageio.Imageio.write(BufferedImage, "png", outputStream), and with an > out-of-the-box JDK installation, the javax.imageio.Imageio stuff does not > support png compression. (png has support for the deflate algorithm > built-in, but it seems you don't *have* to use it when writing out png > files) > > However, by installing an additional package to add to my JDK, I managed to > get a gwt compile to produce compressed png files: > > http://download.java.net/media/jai-imageio/builds/release/1.1/INSTALL-jai_imageio.html#Manual > > Some of my small png files got slightly bigger, but that 1MB png got much > smaller. > > This is a known bug in the JDK, and there's a bug report here: > http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4829970 > > but that's a very old bug report, so may not be fixed any time soon. > > Is this something that GWT could address, so that this would work correctly > out-of-the-box? > > Thanks, > Paul > > > -- > http://groups.google.com/group/Google-Web-Toolkit-Contributors > -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
