Is there any terminal (ADB) command for Android to change the launcher wallpaper?
I know this thread is old and dead, but it came up when I was searching the same topic. So I'm posting a response anyway for posterity.
This works for me on Android 5.1
am start -d file:////data/local/tmp/black_white.png -a android.service.wallpaper.CROP_AND_SET_WALLPAPER -f 0x1 com.android.launcher3/.WallpaperCropActivity