Converting to PNG8 loses transparency

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Hello,

This may be a dumb question but I did google as well as searching archive
but cannot seem to find the answer. I'm trying to convert an PNG32 image to
PNG8 using command below:

gm convert source.png png8:target.png

The command is useful to us as it reduces the image size to half but still
yet good quality (see http://www.sitepoint.com/png8-the-clear-winner/). The
problem is any transparency in source image is lost in the target image.
The closest post I can find in the archive is this one:
http://sourceforge.net/mailarchive/message.php?msg_id=20516411, but it was
about creating an image. But that at least confirm that PNG8 in
graphicsmagick can support transparency.Also, http://tinypng.org/ was able
to do the same conversion but keeps the transparency intact, which means
this is doable.

So what I'm doing wrong? Thank you in advance for you help.I can provide
test images if needed.

Kenneth

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<div dir=3D"ltr"><div><div><div>Hello,<br><br></div>This may be a dumb ques=
tion but I did google as well as searching archive but cannot seem to find =
the answer. I&#39;m trying to convert an PNG32 image to PNG8 using command =
below:<br>

<br></div>gm convert source.png png8:target.png<br><br>The command is usefu=
l to us as it reduces the image size to half but still yet good quality (se=
e <a href=3D"http://www.sitepoint.com/png8-the-clear-winner/">http://www.si=
tepoint.com/png8-the-clear-winner/</a>). The problem is any transparency in=
 source image is lost in the target image. The closest post I can find in t=
he archive is this one: <a href=3D"http://sourceforge.net/mailarchive/messa=
ge.php?msg_id=3D20516411">http://sourceforge.net/mailarchive/message.php?ms=
g_id=3D20516411</a>, but it was about creating an image. But that at least =
confirm that PNG8 in graphicsmagick can support transparency.Also, <a href=
=3D"http://tinypng.org/">http://tinypng.org/</a> was able to do the same co=
nversion but keeps the transparency intact, which means this is doable.<br>

<br></div><div>So what I&#39;m doing wrong? Thank you in advance for you he=
lp.I can provide test images if needed. <br><br></div><div>Kenneth<br></div=
><div><br></div></div>

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