A study of denoising methods for in-line single distance phase image

Phase contrast X-ray image is increasingly popular in biomedical image study. One of the most potential phase contrast imaging methods for medical image application is in-line single distance phase contrast imaging method. However, so far in the studies of applications utilizing phase images, the original phase contrast X-ray images are considered noise-free what is too perfect for real world imaging application. In this study, we focused on The X-ray image of low contrast composite taken in low milliampere-seconds (mAs). Three types, coefficients based, denoising by regularization, and non-local means denoising methods were considered. We find that: Denoise-first approach improves the computed phase image quality; however the contrast-to-noise ratio (CNR) value of denoised image in the region corresponding to high contrast region is larger than the CNR value of phase image computed from denoised result in that region.