iraf.net

NUMBER:	123
MODULE:	imtranspose
SYSTEM:	V2.9
DATE:	Wed Jun  6 08:37:42 MST 1990
FROM:	davis

BUG:	Imtranspose fails with an 'unknown pixel type error' on image of
	type ushort.

STATUS:	The bug has been fixed in 2.10. There is no workaround except to
	change the pixel type of the image to int or long.

NUMBER:	141
MODULE:	identify
SYSTEM:	V2.9
DATE:	Wed Dec 19 16:47:06 MST 1990
FROM:	valdes

BUG:	The automatic line identification algorithm fails to find some
	lines in certain circumstances.

	The source of the problem is when multiple lines in the line
	list end up being centered in the same place in the data.  For
	example if two lines in the list are 4888.1234 and 4889.1234,
	the second one is intrinsically weak, and the data is low
	resolution (say 3A per pixel) then as far as the data is
	concerned there is just one line.  This line will be marked
	twice with the same position but different wavelengths.  The
	complication is that valid weaker lines will be removed based
	on the maxfeatures criteria (for example only the 50 highest
	peak values are kept of which say 10 are multiple assignments
	to the same peaks in the data).   Then after the lines are
	found the minsep criteria is applied to winnow out the multiple
	assignments to the same pixel leaving 40 lines found and 10 of
	the weaker valid lines not found.  This is a complex  behavior
	dependent on data resolution, the initial dispersion solution,
	the line list (the problem occurs with dense line lists used
	for high resolution such as the thorium list used with lower
	resolution data), and the maxfeatures and match parameters.

STATUS:	The bug fix is to winnow out the multiple identifications to
	the same pixel before selecting the maxfeatures strongest
	lines.  The workaround most likely to work is to reduce the
	match parameter so that some of the multiple identifications
	are thrown out based on wavelength differences with the
	dispersion function estimates.  Another thing is to increase
	maxfeatures but this will result in many undesired weak lines.


NUMBER:	328
MODULE:	images.imexpr
SYSTEM:	V2.10
DATE:	Thu Feb 15 15:34:52 MST 1996
FROM:	davis

BUG:	The imexpr task was incorrectly decoding image name operands of the
	form '#.extension' (where # stands for a number, e.g. 123.imh) and
	'../path/image.extension' (e.g. ../dev/pix.im) as numbers, 123.0
	in the first case, 0.0 in the second.

STATUS:	Fixed for the next release of iraf. The only workaround is to rename
	the image if it has the form '#.extension', and avoid image path
	names that begin with '..'.