fiign - low-level manipulation of masks associated to FITS
images
fiign [options and operations]
[<input>] [-o|--output <output>]
In the context of FITS image data processing, "masks"
are per pixel associated meta-data, representing the state of the given
pixel. In general, pixels considered to be somehow "bad" are
marked with these masks in order to exclude or use only with caution during
further processing. These masks can either mark the initial state of the
given pixels (e.g. pixels can be marked as hot or bad pixels, which
describes the detector itself and not the individual scientific or
calibration frames), or masks can be added during the subsequent steps of
the processing (e.g. saturated pixels, "outer" pixels). The
purpose of the `fiign` program is to give a low-level access to these masks.
Although the operations on the images automatically yields the respective
operations on the masks (e.g. if an image is transformed or trimmed, the
associated mask will also be transformed or trimmed with the same geometry),
with this program the masks can be manipulated arbitrarily.
- --convert
<match>:<value>:<reset>:<set>
- Convert masks: from a mask which matches to the
<match>:<value> pair, i.e. the masks with the type of
<match> have a value of <value> the masks specified by
<reset> are cleared and the masks specified by <set> are set.
The <match>, <value>, <reset> and <set> tags are
comma-separated list of mask names (see below).
- -x, --expand
<size>
- Expands the mask with the specified size. Applied after all of the
previous steps were performed.
- -q, --mask-block
block:<mask>:<x1>,<y1>:<x2>,<y2>
- Add a rectangular masked area with the specified mask <mask> and
with the specified coordinates (<x1>,<y1>: lower-left corner,
<x2>,<y2>: upper-right corner, inclusive).
- -q, --mask-block
circle:<mask>:<xc>,<yc>:<radius>
- Add a circular masked area with the specified mask <mask> and with
the specified cenroid coordinates <xc>,<yc> and radius
<radius>.
- -q, --mask-block
pixel:<mask>:<x>,<y>
- Add a masked pixel with the specified mask <mask> to the specified
coordinates <x>,<y>.
- -q, --mask-block
line:<mask>:<x1>,<y1>:<x2>,<y2>
- Add a masked line with the specified mask <mask> connecting the
points <x1>,<y1> and <x2>,<y2>.
- none
- no mask at all
- clear
- same as "none"
- fault
- mask for faulty pixels
- hot
- mask for hot pixels
- cosmic
- mask for marking cosmic pixels
- outer
- pixels originating from out of image areas
- oversaturated
- oversaturated pixels
- bloomed
- "bloomed" pixels (i.e. not oversaturated but neighbouring
pixel(s) may be so)
- saturated
- oversaturated or bloomed pixels
- interpolated
- pixels having an interpolated value (e.g. hot or cosmic pixels are
replaced by the average value of the surrounding pixels).
Report bugs to <apal@szofi.net>, see also
https://fitsh.net/.
Copyright © 1996, 2002, 2004-2008, 2010-2016, 2018-2020;
Pal, Andras <apal@szofi.net>