Glenn Randers-Pehrson on wrote...
| At 01:30 PM 3/13/2007 +1000, Anthony Thyssen wrote:
| > However, it was giving me gif-style transparency
|
| The "pngquant" application by Greg Roelofs will build indexed-color
| PNGs with alpha transparency conveyed in the tRNS chunk. The
| "toucans" image found somewhere on the PNG web site is an example.
|
| Glenn
Thanks Glenn, knew you would have an answer.
Chase...
I found this comment in a 'under construction' area of IM Examples...
=======8<--------
PNG8 was defined by PhotoShop, not the PNG group. I don't know whether
it includes 8-bit transparency or not, and have assumed that it doesn't,
because that gives us a way to force files to still be readable by
Internet Explorer. However "Photoshop CS" still does seem to like it if
the image includes boolean transparency.
=======8<--------
This seems to explain the GIF like 8 bit color indexing that IM
provides.
Also found these tit-bits that may help a little..
=======8<--------
If when reading an image you force IM to create a image color index table
(or palette) then IM will save that image using a "png8:" format...
convert -type Palette input.jpg output.png
To force the use of an single 8bit greyscale channel use
convert -type Scale input.jpg output.png
NOTE: -type is a input image setting, it is not an output setting. As such if
you read an image in with a specific "-type" setting, then apply transforms,
the image type will probably return to a 32 bit color PNG rather than using a
color index table.
=======8<--------
Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]>
-----------------------------------------------------------------------------
You can say a lot in a few simple words,
but a Word Document is a whole lot bigger! -- Anthony Thyssen
-----------------------------------------------------------------------------
Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/
_______________________________________________
Magick-users mailing list
[email protected]
http://studio.imagemagick.org/mailman/listinfo/magick-users
