Re: how can I get the file header size of tiff images?



On Mar 13, 1:44 am, rob.di...@xxxxxxx (Rob Dixon) wrote:
On 12/03/2011 02:53, leaf falling wrote:



how can I get the file header size of tiff images? Thanks a lot.

What exactly do you mean? The TIFF specification at

   <http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf>

say "A TIFF file begins with an 8-byte image file header...". So perhaps
your answer is 8 bytes, but I doubt it.

Does a module like Image::Info
<http://search.cpan.org/~srezic/Image-Info-1.31/lib/Image/Info.pm> help
at all?

Rob

I am actually running the following process:

..OPERATION: CP FROM RAW
..EXISTING RAW FILE: INP000
[Enter name of input file.]
..ENTER BITS / PIXEL IN INPUT IMAGE (8, 16, 32 or -32): 16
[Enter bits used for each pixel in input file. The 32 bit input is
assumed to be floating point! An entry of -32 will read floating point
data and flip the byte ordering to compensate for different
"endedness" of data.]
..ENTER COLUMNS, ROWS & SLICES: 64 64 64
[Enter columns, rows, and slices in input file.]
..ENTER HEADER BYTES TO BE SKIPPED: 512
[Enter bytes in input file header that should be skipped.]
If the input file has 16 bits / pixel the following two questions will
appear. If you are unsure of the correct answers try all four possible
combinations and examine the output images to see which one is
correct:
..ENTER MOST SIGNIFICANT BYTE (1 OR 2): 1
[Different computers have different byte ordering. For SGI files this
is usually 1.]
..FOLD NEGATIVES? (N/Y): N
[Can compensate for data stored as 2's complement integers. Some data
saved as signed integers may need this.]
..NEW SPIDER IMAGE FILE: PIC002
[Enter name for output file.]

It suggests me to use 512, but it is not true from the output image. I
have to try many values to get it right for every image.

.