makeaheader

Purpose:

This program will generate a header (.hdr file) based upon information that you provide.

where the following definitions apply:
filename the name of the header file to be created (.hdr suffix optional) filetype a number from the following menu: 0--8 bits/pixel (values 0 to 255) 1--16 bits/pixel unsigned short ints (values 0 to 65535) 2--16 bits/pixel short ints (values 0 to 32767) 3--16 bits/pixel short ints (values -32767 to 32767) x-dim the x dimension of the image file matrix (e.g., 128) y-dim the y dimension of the image file matrix (e.g., 128) z-dim the z dimension of the image file matrix (e.g., 128) x-size the x size of the voxels in the image file (e.g., 1.4) y-size the y size of the voxels in the image file (e.g., 1.4) z-size the z size of the voxels in the image file (i.e., the interplane distance)
NOTE:: In AIR 2.0, the x, y, and z sizes are no longer optional.

makeaheader pet1 0 128 128 15 2.1 2.1 8.0

This command will generate a header called pet1.hdr specifying 8 bits/pixel, a global minimum of 0 a global maximum of 255, matrix dimensions of 128x128x15 and voxel dimensions of 2.1x2.1x8.0.

For 8 bit data, the headers, and consequently, this program, are relatively straightforward. For 16 bit data, the values of global minimum and global maximum will alter the way that the data is represented internally.
If voxel sizes have to be rounded-off, the smallest voxel size should be rounded downwards and the other two voxels sizes (if different from the smallest voxel size) should be rounded upwards to assure that interpolation to cubic voxels will function properly.