Particle tracking using IDL -- John C. Crocker and Eric R. Weeks
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You can use these routines to deal with the files written by the ThermoNoran "InterVision" software which runs on an SGI. My impression is that these may just be some sort of special SGI image stack format.

IDL> a = read_noran('stack.noran')
IDL> print,parse_noran('stack.noran')

parse_noran prints out information from the header of the file, such as calibration numbers, magnification, etc. read_noran calls parse_noran and then reads in the rest of the images, based on the information from parse_noran. read_noran also prints out the calibration numbers from the header, although no other information.

Note that these image stacks have a curious feature: the last few images stored in the file belong to the beginning of the data set. So, read_noran by default swaps the very last image to the front of the file. For small files this is sufficient, say, files with 10 images or fewer. For larger files, it will be more than one image that is at the end of the file, and so this won't help very much. In fact, it could be a problem because it would take up more memory as it does the swapping. So, you can use the keyword /lomem to skip this action in read_noran and thus save on memory.

I've written some code in epretrack that fixes this problem, more information coming soon.

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