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ccdfill - patch up the holes in an image
ccdfill patches up the holes in an image.
Currently a simple
2-dimensional planar fit is done to the pixel values surrounding ’bad’ pixels.
The size of this area can be choosen by the user.
This procedure will obviously
not conserve flux (see also all=t below), and has to be used with caution.
The following parameters are recognized in any order if the keyword
is also given:
m=3 you will see some singular matrix warnings, and patched values will
be bogus. It is better to set m=4 for those cases.
- Input image(3NEMO)
file. No default.
- Output image file. No default.
- Number of neighbor cells at one side to
use in interpolation/fit. The total number of cells used in the fit will
hence be at most 4*n*(n+1) (this already excludes the central pixel, n=1
uses 8 cells, n=2 uses 24 etc.) [Default: 1].
- Value in the map
that should be patched. [Default: 0.0].
- Normally only bad pixels are
patches. By setting all=t all pixels are re-fitted with a planar fit, effectively
smoothing the map. This will obviously not conserve flux, where applicaple,
and should be used with caution. Default: f
- Minimum number of neighbors
needed to allow a fit. Normally 3 is enough, though this tends to add to
edges. 4 would be more conservative, in which case iter>1 can be used. Default:
- Minimum number of iterations. 0 is also an allowed value, in which
case the image will just be copied unmodified. Default: 1
- If given,
for each point in the map, if a point deviates more than spike from all
it’s 4 non-bad direct neighbors, this value will be reset to bad before the
actually filling will take place. Default: none (not applied)
Edge effects will occur
for large values of iter, use with caution. Really a better bi-linear interpolation
is needed. See also ccdintpol(1NEMO)
if your irregulaties are regular enough.
10-Dec-93 V1.0 Created PJT
22-feb-97 V1.1 added bad= PJT
19-feb-02 V1.2 added all=, m= PJT
3-may-03 V1.3 added iter= PJT
3-may-2017 V2.0 added spike= PJT
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