2D Data

For 2D data the simplest way to examine the results is just to display the output NDF using the KAPPA DISPLAY command. For instance:

     % display clumps mode=scale badcol=red accept

will display the file clumps.sdf so that black corresponds to the lowest clump index and white to the largest, with bad pixels (i.e. pixels not in any clump) coloured red.

If you want to see the actual data values instead of the clump index values, then you can use KAPPA COPYBAD to produce a copy of the original data with all non-clump pixels set bad:

     % copybad data ref=clumps out=data2
     % display data2 mode=perc badcol=red accept

will copy the file data.sdf into the file data2.sdf, setting pixels bad in data2.sdf if the corresponding pixels are bad in clumps.sdf.

Alternatively, you may be interested in the background (non-clump) pixels. To get an NDF containing just the background pixels, do:

     % copybad data ref=clumps out=data2 invert
     % display data2 mode=perc badcol=red accept

The output NDF contains an extension structure holding information about each identified clump. For each clump, the extension contains a minimal cut-out from the input data array that contains just those pixels belonging to the clump². So to display an image of (say) clump 12, do:

     % display "clumps.more.cupid.clumps(12)" mode=perc badcol=red accept

To draw an outline of a clump on top of a previously displayed image of the entire data array, do:

     % display data mode=perc accept
     % outlineclump clumps 12