Check two objects sample the color difference between color differences Δ (L *, a *, b *) Δ (E * ab, C * ab, H * ab) Δ (Y, x, y) Δ (X, Y , Z) or Δ (Rs, Gs, Bs) color space (L *, a *, b *) (* in C * ab, hab) (Y-, x, y) (X, Y, Z) or (Rs, Gs, Bs) the maximum, minimum and mean value function to allow the error to set the automatic memory function (99), and read features mini-USB PC interface