Graphicsmagick how to forcely covert 32bit image to 24bit bitmap

Question

I would like to force all the input image to be converted into 24bit bmp format. what parameters in gm command line I should add?

gm convert input.png -resize 1920x1080 out.bmp

Answer 1

I think i figured out, just let you guys know

gm convert input.png -resize 1920x1080 +matte out.bmp