2001.11.09 15:33 "Two questions re/ Windows ...", by Peter Davis

2001.11.09 18:55 "Re: Two questions re/ Windows ...", by Peter Davis

  1. Does anyone have a working Windows build of this? I noticed there's a makefile generously contributed for WinNT, but I can't get it to build.

If you can't find one there, we include one with ImageMagick (http://www.imagemagick.org).

Thanks. I'm now looking at this site, and it looks very useful.

  1. I'm trying to understand how a TIFF image used as an EPS preview works. Specifically, if I save an EPS with a TIFF preview in Adobe Illustrators, for example, and then open it in Quark, Quark knows how to make the background areas transparent. I'm assuming there's either a transparency mask or a "chroma-key" color in the TIFF, but I don't know how to find it. Any clues on this?

It's stored in the Adobe "private data" (though fully documented in the Photoshop SDK) area along with other things. It's stored as a vector description (it's a clipping PATH after all ;).

I've just succeeded in isolating the TIFF preview from the EPS file, and it appears to contain both a clipping path and an alpha mask. From looking at all the one pixel nooks and crannies in my samples, it appears that Quark is actually using the alpha mask, rather than the clipping path, to display the EPS preview.

ImageMagick includes an API call that will return the clipping path information to you in the form of an SVG snippet.

Thanks again. Is there a function to return the alpha mask? That might allow me to set up a Windows clipping region to mask the image on screen.



     Peter Davis                               Pageflex Inc
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