An x-ray image intensifier (XRII) has many applications in diagnostic imaging, especially in real time. Unfortunately the inherent and external distortions (pincushion, S-distortion and local distortion) hinder any quantitative analysis of an image. In this paper an automatic real-time local distortion correction method for improving the quality of digital linear tomography images is presented. Using a digital signal processing (DSP), this method can work for an image up to 1Kx1Kx12 bit at 30fps. A local correction method has been used because it allows distortions such as those caused by poor axial alignment between the X-Ray cone beam and the XRII input surface and local distortions to be resolved that are generally neglected by global methods.