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ccdfill - patch up the holes in an image
ccdfill [parameter=value]
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.
The following
parameters are recognized in any order if the keyword is also given:
- in=in_ccd
- Input image(3NEMO)
file. No default.
- out=out_ccd
- Output image file. No default.
- n=
- 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].
- bad=zvalue
- Value in the map that should be patched. [Default:
0.0].
- all=t|f
- Normally only bad pixels are patches. By setting all=t all pixels
are re-fitted with a planar fit, effectively smoothing the map. Default:
f
- m=
- 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: 4
- iter=
- Minimum number of iterations. 0
is also an allowed value, in which case the image will just be copied unmodified.
Default: 1
With 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.
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.
image(3NEMO)
, ccdmath(1NEMO)
,
ccdsmooth(1NEMO)
, ccdintpol(1NEMO)
Peter Teuben
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
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