map_sprites
Arguments:
- _nb_sprites>=1,_allow_rotation={ 0=none | 1=90 deg. | 2=180 deg. }
Description:
Map set of sprites (defined as the
nb_sprites latest images of the selection) to other selected images,
according to the luminosity of their pixel values.
Example of use:
$ gmic
image.jpg resize2dy 48 repeat 16 ball {8+2*$>},${-rgb} mul[-1] {(1+$>)/16} done map_sprites 16

Command:
image.jpg resize2dy 48 repeat 16 ball {8+2*$>},${-rgb} mul[-1] {(1+$>)/16} done map_sprites 16