LibTiff Mailing List

I wrote:
>
> However, what you could do for example, is construct the image using
> GDI+ (or something else), then retrieve the bitmap data (from the
> documentation it looks like you need to use Bitmap.LockBits for that),
> convert that from RGB to CMYK and then pass it on to libtiff.

Actually, you don't even have to convert. Just create a BGRA image
(that's the actual byte order that Windows bitmaps use), and pretend
that BGRA = CMYK. So, tell GDI+ to paint in blue when you actually want
to paint in cyan, etcetera. (I may have got the order of the colours
wrong, but you'll find it out easily enough).

					Gerben Vos.


AWARE [SYSTEMS]		Imaging expertise for the Delphi developer
		TIFF and LibTiff Mailing List Archive
	LibTiff Mailing List TIFF and LibTiff Mailing List Archive July 2006 Previous Thread Next Thread Previous by Thread Next by Thread Previous by Date Next by Date Contact The TIFF Mailing List Homepage This list is run by Frank Warmerdam Archive maintained by AWare Systems	Thread 2006.07.05 14:38 "CMYK Tiff", by Ivan Kopcanski 2006.07.06 09:38 "Re: CMYK Tiff", by Gerben Vos 2006.07.06 11:56 "Re: CMYK Tiff", by Gerben Vos 2006.07.07 07:06 "Re: CMYK Tiff", by Ivan Kopcanski 2006.07.07 09:20 "Re: CMYK Tiff", by Gerben Vos 2006.07.06 11:56 "Re: CMYK Tiff", by Gerben Vos I wrote: > > However, what you could do for example, is construct the image using > GDI+ (or something else), then retrieve the bitmap data (from the > documentation it looks like you need to use Bitmap.LockBits for that), > convert that from RGB to CMYK and then pass it on to libtiff. Actually, you don't even have to convert. Just create a BGRA image (that's the actual byte order that Windows bitmaps use), and pretend that BGRA = CMYK. So, tell GDI+ to paint in blue when you actually want to paint in cyan, etcetera. (I may have got the order of the colours wrong, but you'll find it out easily enough). Gerben Vos.

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2006.07.06 11:56 "Re: CMYK Tiff", by Gerben Vos