comp.lang.idl-pvwave archive: archive » Re: reading header and manipulating according to the header information

Home » Public Forums » archive » Re: reading header and manipulating according to the header information

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: reading header and manipulating according to the header information [message #71006 is a reply to message #71005]

Sat, 15 May 2010 09:02

Craig Markwardt
Messages: 1869
Registered: November 1996

Senior Member

On May 15, 10:21 am, sid <gunvicsi...@gmail.com> wrote:
> Hi,
> Since I am using huge data of several years, different kind of
> ccds are used on different days. I need to trim the data to a size
> which depends on ccd size, is there any method to read the header
> information and take the ccd size from there and then to proceed
> further, instead of giving the ccd size manually. Because it is really
> very tedious to check for the ccd size each time and then to proceed.
> Please help out.
> For example,
> in one of my data the ccd size that is 1K by 1k is given in header as,
...

Anything you can do "manually," you can do in a program. The hard
part is usually to make it robust.

Based on the headers you provided, it looks like you have FITS image
files. If you don't already have it, get the IDL Astronomy Library.
It has many routines for reading FITS images and tables. The easiest
one to use is MRDFITS(). MRDFITS() returns the image array which you
can query using SIZE() and then trim as needed.

Simple example:
filename = 'myfile.fits'
img = mrdfits(filename) ;; Read image
sz = size(img, /dim) ;; Determine size of image
szx = sz(0) ;; Number of columns
szy = sz(1) ;; Number of rows
img = img( (0+2):(szx-3) , (0+2):(szy-3) ) ;; Remove outermost two
rows and columns

Good luck,
Craig

Report message to a moderator

[Message index]

		Re: reading header and manipulating according to the header information By: sid on Fri, 21 May 2010 12:37
		Re: reading header and manipulating according to the header information By: Gray on Sun, 16 May 2010 09:13
		Re: reading header and manipulating according to the header information By: sid on Sun, 16 May 2010 07:31
		Re: reading header and manipulating according to the header information By: Jeremy Bailin on Sat, 15 May 2010 16:02
		Re: reading header and manipulating according to the header information By: Craig Markwardt on Sat, 15 May 2010 09:21
		Re: reading header and manipulating according to the header information By: Craig Markwardt on Sat, 15 May 2010 09:02
		Re: reading header and manipulating according to the header information By: Gray on Sat, 15 May 2010 08:02

Previous Topic:	how to retain header info even after writefits
Next Topic:	Re: color plot over greyscale image - postscript

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Thu Oct 09 21:24:17 PDT 2025

Total time taken to generate the page: 0.96050 seconds