In this paper we discussed the method to reduce dimensions of segmentation feature applied to skin erythema image segmentation. Basing on analyzing a lot of erythema images, we proposed a new segmentation feature parameter applied to skin erythema image segmentation. At last, by using the fuzzy-c-means cluster arithmetic, we compared the segmentation speed and segmentation effect of adopting different segmentation features parameter and found that the segmentation result by using the new segmentation feature parameter is better.

Isolation of a new structured acousto optic switch based on an integTatcd optical polarization independent quasi collinear acousto optic tunaSIe filter is studied in detail. The factors that influence the isolation of the optical switch are analysed, the expressions of the isolation are educed, and the isolation of the dev/ce is measured in experiment. It is found that the isolation mainly depends on the TE/TM mode intensity ratio, the mode splitter extinction rate, and the conversion efficiency.

Spatially resolved reflectance close to source has received a great deal of attention recently. This research is considered to develop a new noninvasive technique for measuring the optical properties of biological media. Using Monte Carlo simulations, we investigated the influence of third-order parameter on diffuse reflectance and found that the reflectance decreased with an increase of at a short source-detector separation of approximately 0.7-2 transport mean free paths. We show that the effects of two parameters, and secondorder parameter, on the reflectance are contrary. As a result the influence of the second-order parameter on the reflectance is irregular when the condition is not satisfied.

Influences of the scattering phase functions on spatially resolved diffuse reflectance from a homogenous semi-infinite medium close to source are studied with Monte Carlo simulation. It is shown that the influences of optical parameters higher than the second order on the diffuse reflectance are quite weak in the region from 0.3 to several transport mean free pathes when Henyey-Greenstein phase function or a combined phase function of two parameters are used. But this influence may be substantial if the double Henyey-Greenstein function is used to describe the scattering property of tissue.

In this paper, the auto-con'elation properties of scattering light in random media modulated by ultrasound were studied. The expression of temporal auto-con'elation function of scattering light amplitude in the ultrasound-modulated media was presented. The results show that the auto-correlation function is modulated as the ultrasound is introduced into the media and the modulation amplitude decays with correlation time. The influences of ultrasound amplitude, Brownian diffusion coefficient, scattering and absorption coefficients on auto-correlation function were discussed. The aura-correlation imaging of an object hidden in random media was also studied by the use of Monte Carlo simulations.