median4

function median4(clip a,clip b,clip c,clip d,int "y",int "u",int "v")
{
y = default(y,3)
u = default(u,3)
v = default(v,3)
abmin = mt_logic(a,b,"min",y=y,u=u,v=v)
abmax = mt_logic(a,b,"max",y=y,u=u,v=v)
cdmin = mt_logic(c,d,"min",y=y,u=u,v=v)
cdmax = mt_logic(c,d,"max",y=y,u=u,v=v)
x = mt_logic(abmin,cdmin,"max",y=y,u=u,v=v)
y = mt_logic(abmax,cdmax,"min",y=y,u=u,v=v)
raveragew(x,0.5,y,0.5,lsb_out=true,y=y,u=u,v=v).ditherpost(mode=6)
}