Hi Siamak,

This has been pretty confusing. You seem to want to read a
NIFTI dataset into MATLAB, perhaps first using some program
to extract a single slice, is that right?

This has nothing to do with the afni viewer, and nothing to
do with the bmp or jpeg formats, since you want the actual
data (not converted to some picture format). Am I mistaken?

If you just want to load an AFNI or NIFTI dataset into
MATLAB, try the BrikLoad function from our AFNI MATLAB
library:

[afni.nimh.nih.gov]

Extracting a single slice from there should be trivial. Or
you can extract it beforehand via the 3dZcutup program that
I mentioned, and then read it in via the library.

If this is not what you are trying to do, please let us know
your specific goals.

- rick