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The article presents a strategy for image segmentation by active contours. Results suggest the versatility and flexibility of the strategy for accommodating a diversity of image features for segmentation.

Radiation hardness is one of the fundamental parameters characterizing a scintillator. The reason is that ionizing radiation often induces the formation of color centers in the irradiated material. These centers are related to lattice defects and may absorb light in the visible range. Possible overlap of the induced absorption spectrum with the emission spectrum of the scintillator can reduce the number of photons emitted by the scintillator, influencing negatively the energy resolution of the detector. In this paper, the irradiation ([sup.60]Co) induced absorption of [Ce.sup.3+] ([Tb.sup.3+]) phosphate scintillating glasses is reported in the dose range 1 / 10 Gy. Irradiation tests were performed in the 'Calliope' irradiation plant, placed in the Research Centre ENEA-Casaccia in the same dosimetric point (3.7 Gy/h), and the irradiation-induced damage was investigated by transmission measurements. Results are discussed by taking into account the possible dependence of radiation hardness on the composition of glass matrix. Index Terms--Glass, radiation effects, scintillation detectors.