Make Hugin tools (align_image_stack, enfuse, ...) save output file in same format as input file (if same extension)

[Andi S]

I feed align_image_stack with 16 bit TIFF files exported from Lightroom without an alpha channel, but it produces unnecessarily huge TIFF files by adding the alpha channel to the output files. How I can prohibit this without applying another costly step to remove that channel?