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On Wed, Jan 23, 2008 at 09:18:06PM +0100, Timur Ametov wrote:
> I have another question. Can (or how can) I change single pixels in a
> tiled TIFF-Image.
> 
> I have only one idea how can I do this:
> 1. read a tile, where the pixel is, into buffer
> 2. change the pixel
> 3. rewrite tile
> 
> but maybe there are another solutions?

In case of uncompressed tile you can try to overwrite the pixel yourself
using TileOffsets table to get the data disk layout. But do not forget
that the tile can be compressed and you need to decompress it to get
access to individual pixels. 

Best regards,
Andrey

-- 
Andrey V. Kiselev
ICQ# 26871517


AWARE [SYSTEMS]		Imaging expertise for the Delphi developer
		TIFF and LibTiff Mailing List Archive
	LibTiff Mailing List TIFF and LibTiff Mailing List Archive January 2008 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 2008.01.21 19:38 "How to clip an image with LibTiff", by <erez.har-tal@walgreens.com> 2008.01.22 10:24 "Re: How to clip an image with LibTiff", by Gerben Vos 2008.01.22 10:38 "Q: Change single pixels in a tiled Tiffs", by Timur Ametov 2008.01.23 20:18 "Change single pixels in a tiled Tiff-image", by Timur Ametov 2008.01.24 12:14 "Re: Change single pixels in a tiled Tiff-image", by Andrey Kiselev 2008.01.24 12:35 "Re: Change single pixels in a tiled Tiff-image", by Andy Cave 2008.01.22 20:39 "Re: How to clip an image with LibTiff", by Andrey Kiselev 2008.01.24 16:09 "How to clip an image with Tiffcrop", by Beppe Costagliola 2008.01.22 22:30 "Re: Tiff Digest, Vol 44, Issue 8, Cropping faxes", by Richard Nolde 2008.01.22 23:59 "Re: Tiff Digest, Vol 44, Issue 8, Cropping faxes", by Andy Cave 2008.01.23 00:39 "Tiff Digest, Vol 44, Issue 8, Cropping faxes", by Richard Nolde 2008.01.23 10:51 "Re: Tiff Digest, Vol 44, Issue 8, Cropping faxes", by Andy Cave 2008.01.24 05:23 "TIffcrop might be called tiffextract", by Richard Nolde 2008.01.24 12:07 "Re: TIffcrop might be called tiffextract", by Andrey Kiselev 2008.01.24 12:32 "Re: TIffcrop might be called tiffextract", by Andy Cave 2008.01.25 05:52 "Tiffcrop and tiff2pdf", by Richard Nolde 2008.01.25 09:25 "Re: Tiffcrop and tiff2pdf", by Beppe Costagliola 2008.01.25 14:41 "Re: Tiffcrop and tiff2pdf", by Beppe Costagliola 2008.01.26 00:03 "Re: Tiffcrop and tiff2pdf", by Richard Nolde 2008.01.24 12:14 "Re: Change single pixels in a tiled Tiff-image", by Andrey Kiselev On Wed, Jan 23, 2008 at 09:18:06PM +0100, Timur Ametov wrote: > I have another question. Can (or how can) I change single pixels in a > tiled TIFF-Image. > > I have only one idea how can I do this: > 1. read a tile, where the pixel is, into buffer > 2. change the pixel > 3. rewrite tile > > but maybe there are another solutions? In case of uncompressed tile you can try to overwrite the pixel yourself using TileOffsets table to get the data disk layout. But do not forget that the tile can be compressed and you need to decompress it to get access to individual pixels. Best regards, Andrey -- Andrey V. Kiselev ICQ# 26871517

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2008.01.24 12:14 "Re: Change single pixels in a tiled Tiff-image", by Andrey Kiselev