2006.07.20 13:55 "[Tiff] newbiequestion: [?] backup complete ifd > private ifd", by Karin Hoehne

Hi there, everybody.

I guess this is somewhat of a newbiequestion...

for a course at the university i do have following assignment: for data-preservation-reasons [> improve relevant file qualities i.e. for digital libraries]:

copy the header [? is this possible ?] and the IFD of an existing tiff-file and insert this 'copy' as a new ifd inside the file.

in other words:

2 chunks of data are changed parallel and synchronized by a piece of software. if these two chunks are >not< identical, do something like a warning, that there might be something wrong with the file. [i.e. display-qualities, filesize, whatever]

this is my prblem so far...

-------------------------------------------------- after doing pretty much homework by reading the archive of >this< list, several techspecs and playing around with the libtiff, i pretty much figured out some basic questions and now i am hoping you could perhabs give me a hint, if i am [basically] on the right track:

[?]

Is there a way to copy/backup an entire ifd and create a new, pivate one at the end after the last ifd?

Well, I guess not, but one can hope... :)

[?]

Is there a way [which i couldn't figure out till now] to print a list of all tags - including private tags?

[i mean in this way: is there something or not, indicated by an integer like 0 and 1] or [>some< kind of information of a private tag.]

[?]

According to this: http://www.asmail.be/msg0054967690.html: As far as I don't know the datatype of possible private tags, do i have do restrict the task on the 45 baselinetags?

[?]

Is there some elegant, automated implementation in the libtiff to copy all of the baselinetags or do i have to write a readingfunction for every single tag?

-------------------------------------------------- Well, as mentioned before, i don't hope for anything like real code but something like a hint to solve the problem. :) / thx in advance /karin