Image reconstruction algorithm based on maximum likelihood-expectation maximum for radiography

To improve the reconstruction quality of flash X-ray radiography containing noises, an image reconstruction algorithm based on ML-EM (maximum likelihood-expectation maximum) for radiography is studied. According to the characters of low signal to noise ratio and smoothness in pieces, proper filter restraining the noises during the processing of reconstruction is adopted, the result reconstructed by this algorithm is less influenced by noises and preserves the boundary character of the object. Simulation indicates that ML-EM reconstruction algorithm based on noises constraint can give satisfactory results.