[fitsbits] Start of the FITS Region File Public Comment Period

[Craig Markwardt]

William Pence <William.Pence at nasa.gov> writes:
> A FITS Region file is a FITS binary table that defines a spatial region
> of a 2-dimensional image.  The region file is often used to define an
> area that is to be included or excluded from certain data processing
> operations on the image. The region is specified as the union or
> intersection of geometric shapes, such as 'circle' or 'rectangle'. The
> REGION table is the FITS equivalent of the ASCII text region file that
> has long been used by the ds9 image processing program and its
> predecessor, SAOimage.

Another comment:

The sample fits header lists TCRPXn, TCRVLn and TCDLTn as required
keywords for RA and DEC columns.  Are these really required?  Does
that mean that one cannot simple have a floating point (1E) column
describing the RA and Dec?

I note that X, Y and R are all in pixel space as well, which means
that one cannot define the position and radius in physical units?

Craig Markwardt