Indeed, saving a 4-channel image to a .jpeg file assumes the data are in CMYK.
To discard the alpha-channel from your .png data, you can use to_rgb :
$ gmic filein1.png to_rgb -o fileout1.jpg,75
Indeed, saving a 4-channel image to a .jpeg file assumes the data are in CMYK.
To discard the alpha-channel from your .png data, you can use to_rgb :
$ gmic filein1.png to_rgb -o fileout1.jpg,75