[WWdevel] Re: [webwork-user] Re: pdf generation problem and image problem

[Davide P.C. <dp...@un...>]

>> If you change -bgTransparent to -bgtransparent (i.e., remove the 
>> capitalization)
>
> Is this a bug in Constants.pm?

No, it's a bug in MSIE.  :-)

In dvipng prior to version 1.6, both forms meant the same thing.  In 
1.6 and later, the first gets you alpha-channel transparency while the 
second gets your single-bit transparency.  While every other modern 
browser handles alpha-channel transparency, MSIE only does this if you 
include a horrible proprietary call to a special image filter that 
references the alpha image and link the source image to a blank image 
file (if I remember correctly).  I would love to switch to 
alpha-channel transparency so that the background colors work better, 
but as long as we are saddled with the lumbering and decrepit beast 
known as MSIE, we have to dump down to its (in-)capabilities.  Not that 
I'm upset by this.  >:-p

The upshot is, though, that Constants.pm probably should have the 
lower-case transparency to avoid the alpha-channel problem.

Davide