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2008.01.16 23:23 "Re: Q: TIFFWriteRawTile()", by Frank Warmerdam
Timur Ametov wrote:
> Hallo Everybody,
>
> I'm not really sure, that I understood that's right. Is ist really not
> possible, to change / add some tiles to tiled tiffimage later? I mean, after
> tile was already once written and / or tiffimage was already closed?
>
> If it's so, why is it so? If itsn't so, how can i change tile later. I tried
> it, but there were no changes in the image.
Tim,
What version of libtiff are you using?
Looking in the code I see that TIFFWriteRawTile() skips a bunch of stuff
that is done by TIFFWriteEncodedTile() that might be important for rewriting
tiles such as this:
if( td->td_stripbytecount[tile] > 0 )
{
/* Force TIFFAppendToStrip() to consider placing data at end
of file. */
tif->tif_curoff = 0;
}
I never use the "Raw" interfaces so it is entirely possible they are not
functioning properly with regard to some of the update-in-place logic.
But - in theory - it is intended that what you want should work if you open
a file in update mode.
Best regards,
--
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