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TIFF and LibTiff Mail List Archive

Thread

2008.04.17 09:58 "[Tiff] a question about creating transparency of the image in TIFF", by Константин_Луцкий
2008.04.17 14:03 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Frank Warmerdam
2008.04.17 15:18 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Gerben Vos
2008.04.17 21:14 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Chris Cox
2008.04.17 21:48 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Bob Friesenhahn
2008.04.18 12:53 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Edward Lam
2008.04.18 15:41 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Bob Friesenhahn
2008.04.18 15:56 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Edward Lam

2008.04.18 12:53 "Re: [Tiff] a question about creating transparency of the image in TIFF", by Edward Lam

Also, the TIFF spec. states that images with associated alpha (transparency) must be premultiplied.

The TIFF specification does not prevent a colormapped file with transparency but the colors in the colormap would then need to be premultiplied, which could be a challenge to surmount. As a result, no one does this.

Sorry, I don't understand this. We output TIFFs with premultiplied RGB colors and associated alpha. How is this a "challenge"?

-Edward