cp /workspace/scratch/matting.py /workspace/scratch/matting0.py; python - <<'PY'
p='/workspace/scratch/matting.py'
s=open(p).read();s=s.replace("v=F-B;num=((a-B)*v).sum(2);den=(v*v).sum(2)\n alpha=np.clip(num/(den+1e-8),0,1)","v=F-B\n # solve matte while permitting background illumination to vary\n bn=B/(np.sqrt((B*B).sum(2))[:,:,None]+1e-8)\n perp=v-(v*bn).sum(2)[:,:,None]*bn\n diff=a-B\n num=(diff*perp).sum(2)+.015*(diff*v).sum(2)\n den=(perp*perp).sum(2)+.015*(v*v).sum(2)\n alpha=np.clip(num/(den+1e-8),0,1)")
open(p,'w').write(s)
PY
OPENBLAS_NUM_THREADS=1 python /workspace/scratch/matting.py