[Kst] extragear/graphics/kst/devel-docs

[Ted Kisner]

SVN commit 537169 by tskisner:

Add info about WCS after reading about and testing the library

 M  +13 -2     fits_datasource.txt  


--- trunk/extragear/graphics/kst/devel-docs/fits_datasource.txt #537168:537169
@@ -2,8 +2,9 @@
 ============================
 Revision History
 ----------------------------
+
+2006 05 04 : Ted K.  Added info about WCS
 2006 05 03 : Ted K.  Initial proposal
-
 ----------------------------
 
 This is a proposal for a new general FITS datasource (called fitsfile).  There
@@ -67,9 +68,19 @@
 
 WCS Extensions
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-Still looking into this...
+The WCS system provides a way of specifying the coordinates of each pixel
+value in a FITS image.  This can be done by specifying mapping parameters, or
+even by specifying every pixel's coordinates in a binary table extension. 
+This is great, but what can we do with this information?  The best we can do
+at this point is maybe support some limited types of coordinate mappings
+(rectangular ones).  Full support of WCS projections will not be possible
+with kst until we have a complete 3D display framework.
 
+Note that WCS is implemented as an external library.  It is small and GPL'd,
+so it may be easier to just include the files we wish within the fitsfile
+datasource.  This can be discussed more later.
 
+
 Healpix, LFIIO, and Miscellaneous
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