Help: Issue with changing image to halftone with transparency backgroung

[rich2005]

Quote:...snip...I understand gimp has a learning curve it's just discouraging on what is a fairly simple thing as this to keep finding yourself not accomplishing what seems simple.

Guessing this was not a Gimp tutorial or was something ancient.

Apply the GEGL newsprint filter to an image with transparency and the transparency is replaced. The alpha channel filled with white. You can duplicate the alpha channel before applying newsprint and restore via a selection / cut selection. The image still has an alpha channel. 

   

An easier way is isolate the area with a selection before applying newsprint.

   

If your image already has a transparent background, get the selection from Layers -> Transparency -> Alpha to selection  Otherwise use one of the selection tools (depends on image background)
Remember to remove the selection on completion Select -> None

Another way if the image already has transprency. Lock the alpha channel for that layer (it is per layer). Top of the layers dialogue
Remember to toggle off when finished.

   

Edit: It might help understanding the origins of half-toning. It is to provide shading to what otherwise would be solid colour. It is a printing process. There is no white ink. The colour of the printed-on material (paper / cloth) replaces the white in the image. For printing purposes the transparent background is not required.