A bimodal energy model for correcting beam hardening artefacts in X-ray tomography

As a consequence of the polychromatic X-ray sources, used in micro-computer tomography (/spl mu/CT) and in medical CT, the attenuation is no longer a linear function of absorber thickness. If this nonlinear beam hardening effect is not compensated, the reconstructed images will be corrupted by cupping artefacts. Here, a bimodal energy model for the energy spectrum is presented, which may be used for reduction of artefacts caused by beam hardening. In essence, this correction method is a linearization technique based on a physical model, where no a priori knowledge about the spectrum of the source is required.