ABSTRACT
Objective To amend the errors between projective image center and the actual rotational center and improve the quality of reconstructed images. Methods The impact of reconstructed image in which the projection center and the actual center caused the deviation is analyzed, and provides the ways that is based on the gray value difference of objects and background in projection image to calculate actual rotational center, and then mends the projective image based on the actual rotational center. Results The difference between the actual rotational center and the calculated projective image center is less than one pixel. The quality of the reconstructed images is improved greatly. Conclusion The correction method is based on projective images, no need to increase the auxiliary conditions and the number of projection images. And the way as the pre-process of reconstruction, only needs small amount calculation, doesn't affect the reconstructive speed.