Due to be sensitive to noise for unsymmetry target

General center of mass can not locate well for optical tracking

and the macro divided method has good anti-noise capacity

but it is too computationally intensive. The macro-pixels method was used to reduce calculation time. For the unsymmetry target of 4×4 pixels in 128×128 pixel spot picture

the value of r could be optimal as 36 pixel of Micro pixel dimensions and target macro-pixels enlarged to 2 pixel according to less calculation time and better in anti-noise capacity. The value of r is 1 when SNR is 5 dB. Dynamic picture test shows that the improved arithmetic has 18~20 frame/s of processing speed.