1. An X-ray CT image processing apparatus comprising an image memory means (1) for storing the tomographic image of an object to be examined reconstructed based on a plurality of signals representing the intensity of X-rays passing through the cross section of the object in a plurality of directions within the cross section thereof, a bone image extraction means (2,3) connected to said image memory means for extracting an image representing the bone from the image stored in said image memory means, a weight function memory means (4) for storing 2-dimensional weight functions, a correcting image forming means (5,6) connected to said weight function means and to said bone image extraction means, for forming a correcting image by adding 2-dimensional weight function provided from the weight function memory means while aligning the center with the image data of the bone image extracted by said bone image extraction means by using said bone image as a mask, and an image addition means (7) connected to said image forming means and to said image memory means, for adding the correcting image formed by said correcting image forming means to the reconstructed image of said image memory means.