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32bit signed integer problems [message #11460]

Mon, 13 April 1998 00:00

Burkhard Prause
Messages: 6
Registered: February 1997

Junior Member

I try to read what I believe are 32 bit signed integer binary data
files.

They represent three dimensional data structures of 256 x 128 x 128
pixels. Each file therefore is 16777216 byte long. I read them into IDL
as follows:

> openr, 1, file
> array=lonarr(256,128,128)
> readu, 1, array

Array then turns out to contain sheer noise. If I read the data file
into a one dimesional vector, then extract 16 bit integers by reading
every third and fourth byte into a 256x128x128 integer array, I can
produce the "correct" image. So my data set is not garbage. However, by
doing this I basically limit my contrast, because all values larger than
2^16 are read as 65536.

Any suggestions what I may be doing wrong here?

--
************************************************************ ********************
BURKHARD A. PRAUSE
DEPARTMENT OF PHYSICS
UNIVERSITY OF NOTRE DAME
NOTRE DAME, IN 46556
bprause@campra.phys.nd.edu
(219) 631-4088
Fax: (219) 6315952
************************************************************ ********************

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		32bit signed integer problems By: Burkhard Prause on Mon, 13 April 1998 00:00
		Re: 32bit signed integer problems By: Burkhard Prause on Sun, 03 May 1998 00:00

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