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ccdppm - convert image to a PPM file, with optional color cable


ccdppm [parameter=value]


ccdppm converts a NEMO image to a 24bit PPM file. A color table can be optionally added, also in 8bit mode.

ppm files are probably the most versatile output graphics format, since it is very easy to write (no special library is needed) and they can be easily converted to other formats (gif, jpg,....) and are understood by most image processing systems.


The following parameters are recognized in any order if the keyword is also given:
Input image filename. Must be a image(5NEMO) . Currently the 3rd dimension is ignored, and for datacubes the first slice is taken. See ccdsub(5NEMO) to select a plane. No default.
Output PPM filename. No default.
Overrride data minimum used in scaling. By default it will look for the minimum.
Overrride data maximum used in scaling. By default it will look for the minimum.
Use this as masking value to ignore data. By default no data is considered bad.
optional selection of a lut from NEMODAT/lut. Currently the full path to the file must be given. By default it will be using a grey scale (red=green=blue).
Force up to 256 discrete colors. This can be useful if you want to convert the normally 24bit ppms to 8bit images and not ’loose’ any colors in the conversion. [false].


Here is an example to take the 5th plane from a fits file into a 24bit PPM file:
    % fitsccd cube.fits - | ccdsub - - z=4 | ccdppm - plane4.ppm lut=$NEMODAT/lut/ronekers.lut

See Also

fitstiff(1NEMO) , lut(5NEMO)


$NEMODAT/lut : repository of lut(5NEMO) color lookup tables.


Peter Teuben

Update History

17-Dec-03    V1.0 Created (100 year Wright first flight anniversary)    PJT

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