2009.12.28 19:46 "Re: [Tiff] bug in tiff2pdf, when handling Lab images", by Manlio Perillo

2009.12.28 19:46 "Re: [Tiff] bug in tiff2pdf, when handling Lab images", by Manlio Perillo

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Sergius Bobrovsky ha scritto:
> Hello,
>
> recently, I've faced this problem too.

> trying to fix this bug i found that tiff2pdf just do not write > /BlackPoint before second array.

> in other words, correct dictionary should be something as following:

> /ColorSpace [/Lab <<
> /WhitePoint [0.9643 1.0000 0.8251]
> /BlackPoint [0.9643 1.0000 0.8251]
> /Range [-127 127 -127 127]
>>> ]
>

No, this is wrong.

Try to open the resulting document with Acrobat Reader!

The BlackPoint can not be the same as WhitePoint.

As far as I understand, Acrobat reader use the value of BlackPoint for gamut mapping.

Other viewers (like KPDF) don't do gamut mapping, so the image rendering is the same.

> [...]

Regards Manlio

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