  New lensless diffractive X-ray technic for micro-scale imaging of biological
tissue is based on quantitative phase retrieval schemes. By incorporating
refraction, this method yields improved contrast compared to purely
absorption-based radiography but involves a phase retrieval problem since of
physical limitation of detectors. A general method is proposed in this paper
for one step reconstruction of the ray integral of complex refractive index of
an optically weak object from intensity distribution of the hologram.
