This paper presents the new methods of suppressing CN-sequence so as to detect the subpixel target

point target and a few pixel target. First

the methods of accurately estimating the shift parameters between the successive frames are presented

and the equations of calculating 2-D subpixel shift parameters

dx and dy

are deduced. Then

to solve interpolated image

the equations of the FFT interpolation method in frequency field are emphatically deduced. Also

the interpolation control parameters are defined

and the method of interpolating and selecting points（MOISP） is presented. Therefore

a set of algorithms to suppress CN-sequence is set up. The algorithms have been crried out and the CN reJection rates are all more than 85 percent for the selected real-world infrared and television image sequences. The main components of surplus image are the additive uncorrelated noise

i. e. UCN-sequence

except a few target component.