If anyone decided to make use of the gradient generator code I posted yesterday, be advised that I just added alpha channel (i.e. transparency) support. I’ve updated the source code to include these new changes.
Something strange I found out is that PHP only supports a 7-bit alpha channel, even though PNG (and really any image format supporting transparency) uses the same number of bits for the alpha channel as for the red, green, and blue1. I’m assuming this is because PHP uses 32-bit signed integers, and if they let the alpha channel use all 8 remaining bits they would use the sign bit. And heaven forbid people need to know a little bit about twos-complement. Oh well.
And of course, if you use transparent PNGs, you should know they are not supported by IE6. But I’m guessing any IE6 users out there are becoming increasingly aware of the fact that a lot of sites look strange for them.