Low dose CT image enhancement based on second generation Curvelet transform
Naixin Qi · Computer Engineering and Applications Journal · 2010
Low dose CT has low Signal-Noise Ratio(SNR) and bad contrast.The second generation Curvelet transform is used to enhanced low dose CT images of infant brain.Firstly,the CT source images are decomposed by Curvelet transform.Then nonlinear enhancing function is applied to enhance the image’s global contrast in the low frequency sub-band,and threshold denoising method is combined with non-linear gain method,it can reduce the noise and enhance the details of image at each scale in the high frequency sub -band.Compared with wavelet and histogram equalization,enhanced images based on the second generation Curvelet transform show that image SNR and contrast are increased,image edges are preserved.It has a good visual effect.