Note: I think indexed images are not supported by the PNM format.
If this is true but you want to save images, you may want
to replace the corresponding write-pnm-to-stream method with
one that converts the indexed image to an RGB image then
calls write-pnm with it.
If I am wrong and PNM does support indexed images, then please
let us know so we can add the code (or you can of course send
the code directly).
Cheers,
Yes my plan was to convert to an RGB image, but I thought I may as well do the conversion on the fly within write-pnm-to-stream specialised on indexed-images method to save building a full image, it's just a look up of the colour map table.