Since computer tomography (CT) image has been widely applied in clinic diagnostics, while for many applications the
information directly provided by CT images is incomplete corrupted by noise or instrument defect, there has great
demand to further the processing methods for improving the CT image quality. Among all image features, the edge
profile of clinic focus has obvious influence on accurately translating CT image. In this paper, the wavelet filtering
algorithm based on modulus maximum method is put forward to extract and enhance the CT image edges. Edges in the
brain lobe CT image can be outlined after wavelet transform, during which the wavelet assigned as the first order
derivative of Gauss function. Further manipulation through maximum threshold checking to the modulus have been
attenuated the pseudo-edges. After segmented with the original CT image, the edge structure has been distinctly
enhanced, and high contrast is achieved between the brain lobe microstructure and the artificially established edges.
The proposed algorithm is more efficient than the common first order differential operator, for the latter it even
deteriorates the edge features. The algorithm proposed in this article can be integrated in medical image analyzing
software to obtain higher accuracy for symptom interpretation.
The temporal actions of free photoelectrons and shallow trapped photoelectrons in the AgBrI-T grain emulsion were obtained with the microwave absorption and dielectric spectrum technique at the same time. The results indicate that the electron trap effect of sensitization center changes from shallow to deep with the increase of sensitization time. When the function of chemical sensitization center is shallow electron trap effect, the decay of electron is slower and the decay time and lifetime of the photoelectron in sensitized sample are longer than that in unsensitized sample because the sensitization center holds back the recombination between the electron and the hole. When the function of chemical sensitization center is deep electron trap effect, the decay of electron is quicker and the decay time and lifetime of the photoelectron in sensitized sample are shorter than that in unsensitized sample because the sensitization center deeply traps the electrons. The optimal sensitization time is gained according to the relationship between decay time of photoelectron and sensitization time.