Object tracking technology combined with image stabilization is called tracking technology based on image
stabilization. Moving objects affect stabilization compensation in tracking algorithm based on image stabilization. The
middle value method, former background method and dynamic clustering method are not useful for rotate or non-rigid
objects. Fuzzy Clustering of feature points is proposed to solve these problems. First background and objectives
membership value of the pixel are calculated, and then pixels are classified to background and target categories
accurately by defining membership threshold of the background and targets. Experimental results show that fuzzy
clustering algorithm resolves the moving target interference problem in image sequence and realizes steady tracking of
object. It is proved to be more robust and less sensitive to the numbers of initial clustering.
To achieve a good quality of image, piston of segment mirrors is required to be detected and removed down to a small
λ. The details of the diffraction-interference pattern formed by the subaperture are sensitive to piston when
observed on the image plane. An improved image matching method is introduced to detect piston according to the
characters of the interference-diffraction patterns. Templates are made according to the parameters of the system.
One-dimension projecting production-moment correlation method and projecting central moment eigenvector method
are used in different conditions. The great advantage of this method is that there is no need of calibration so the
measurement error is reduced. The operation is simplified to reduce the computation complexity by three matching steps.
The measurement range is about um 25 ±<i>um</i> and the measurement error is less than 10<i>nm</i>. The experiment is carried out
on a platform. Piston is introduced to the parallel-light by a piston generator which is controlled by a PZT. CCD with the
pixel size 4.65<i>um</i>*4.65<i>um</i> is used to receive the image. The experiment result is basically consistent with the theory.
Large segmented mirrors require efficient co-phasing techniques in order to avoid the image degradation due to segments
misalignment. Detecting the piston error in high precision is critical to phasing the segmented mirrors. The energy ratio
method, compared with the peak ratio technique, is presented in this paper to detect the piston. It focuses on a single
quadrate intersegment subaperture which straddles two segments .This method provides a way to extracting some
information on piston error. The details of the diffraction-interference pattern formed by the subaperture are sensitive to
the piston when observed on the image plane. This method has several advantages compared with the peak ratio
technique. The simulation results show that. the energy ratio method is good in detecting the piston error and is better
than the peak ratio technique in robust and reliability.