iraf.net

NUMBER:	302
MODULE:	apscatter
SYSTEM:	V2.10-V2.10.4
DATE:	Tue Jul 18 17:35:37 MST 1995
FROM:	valdes

BUG:	If the aperture trace functions cross or cause the apertures
	to overlap then the algorithm for finding the scattered light
	pixels outside the apertures gets confused.  This can have the
	consequence of either using data within an aperture or a memory
	error (memory corrupted or segmentation violation).  The workaround
	is to insure the aperture definitions and traces do not behave in
	this way.  One way to check this is with APEDIT after the apertures
	have been defined and traced.  In APEDIT you can examine various
	lines with ':line #' and the data line and apertures will be
	shown.  Look at the first line and last line in particular.  The
	interactive option of APSCATTER selecting various lines can also be
	used though this may crash in the same way.

STATUS:	A different algorithm will be used in the next release to
	correctly find the scattered light points even in the unreasonable
	case where the apertures cross.

NUMBER:	403
MODULE:	fixpix, ccdproc, display
SYSTEM:	V2.11-V2.11.1
DATE:	Fri Jun  5 09:45:47 MST 1998
FROM:	valdes

BUG:	When fixing regions by interpolation along columns/across lines,
	which may be set by the user or automatically by finding the
	narrowest direction across a region of bad pixels, it is possible
	to get a segmentation error or error related to referencing invalid
	memory.  Whether this error occurs depends on the contents
	of memory.  If no error occurs the result is correct.

	One workaround is to use only interpolation across columns/along
	lines if this makes sense.  Another workaround is to add a dummy
	region with interpolation along columns covering all the columns.
	For example the first or last line as in '1 3072 1 1' for an image
	with 3072 columns.  It is also possible to break up the operation
	in FIXPIX using multiple passes.  For example if a bad pixel region
	is described by the rectangle '2000 3024 510 512' then two passes
	using '2000 2500 510 512' and '2500 3024 510 512' may work.

STATUS:	Fixed in the next release.