[AstroPy] Moving Ahead with Raw Image Conversion
sierra_mtnview at sbcglobal.net
Mon Apr 13 12:38:40 EDT 2009
Hi, not familiar with much of anything in numpy, then again, I'm not
anxious to read through the 300+ page manual. :-)
Well, let's see if I can explain this in py-talk. Here's a small program
I wrote to get the raw image
for j in range(2):
for k in range(5):
print 'info:', len(raw_image), type(raw_image)
make_array, instead of working on the 307200 byte(640x480) string
representing the image, is used to see if I can generate a 2x5 array
like that apparently needed to represent the image to pyfits. The above
info: 307200 <type 'str'>
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9] <--- my fictional 2x5 image as a py list.
[[0, 1, 2, 3, 4], [5, 6, 7, 8, 9]] <--- the type of structure I think
numarray(numpy equivalent) wants.
I'm looking at page 7 of the FITS manual, and I see in the middle,
hdulist.data. This appears to be where the data(image) goes. At the
top of page 10, the steps to construct a simple fits file are shown.
numarray is used. Simply put, how do I proceed from here?
I've attached the 'sent_internal.raw' file. It may cause this msg to be
rejected by the mail list.
Jim Vickroy wrote:
> Wayne Watson wrote:
>> I've pretty much gotten my 640x480 1 byte, "raw" image under control
>> within Python Image and Python file use. I wrote a file of 307200 bytes
>> in bytes, byte representation of characters. I couldn't see anything
>> within pyfits or numpy that would help me do that. Now I believe I'm in
>> a position to use pyfits to create a fits format file. The next step is
>> to arrange the image (data) into a 640x480 array. I can do that in
>> python, but would like to know how it can be done in numpy, for the
>> experience. The IDA tutorial talks to making arrays, but I do not see
>> where they work with creating an array with fresh data. Once that's
>> done, then I should be able to work out from a reading of page 10 in the
>> pyfits manual.
> Hello Wayne,
> Could you post a sample script illustrating exactly what you want to do
> along with some sample output showing how it is failing to do so?
> Are you familiar with the numpy.ndarray.reshape() procedure?
> -- jv
> AstroPy mailing list
> AstroPy at scipy.org
Wayne Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
All the neutrons, and protons in the human body occupy
a cube whose side is 5.52*10**-6 meters (tiny!). That
adds up to a 150 pound person. It's not a surprise that
we are mostly space. (Calculation by WTW)
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