AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2001.10.09 11:31 "", by Cecilia Rodrigues
2001.10.10 07:33 "Re:", by Joris Van Damme

2001.10.10 07:33 "Re:", by Joris Van Damme

Can anyone give me suggestions regarding.......

Yeah, I can. I suggest my answer to this question, posted to you and the mailing list on mon 01 oct, quoted below.

Asking about anything in particular that you did not understand will be more efficient than reposting the same question three times in the course of a couple of hours.

Joris

------

Joris Van Damme wrote:
>
> Cecilia Rodrigues wrote:
> > I need to specificy the offset i.e offset of where exactly the data will
> > start.so is there any method to calculate the stripbyteoffset?????
>
> StripByteOffset is supposed to point to your strips. So, their values
> will depend on how exactly you want to append this IFD.
>
> One way would be to
> - append the strips first (note that you KNOW where you write them)
> - append the IFD with known strips byte offsets
>
> If you want to write the IFD first, you'll need to take a look at the
> rest of your writing code to figure out where the strips are going to
> end up (or fill in these values at a later time or something).
>
> Same goes for *any* tag data requiring more than 32bits. Either you
> already appended the data to the file by the time you append the IFD,
> and you know where it is, or either you'll have to examine your writing
> code in order to come up with a good method to determine where it's
> going to end up (or fill in these values at a later time or something).
>
> Note that this 'appending' sceme does not include true 'memory
> managment'. Eg, if you add a page to a tiff file from which pages have
> been 'deleted' at some time, 'appending' means that you do not attempt
> at recovering that space.
>
> Joris