It is well known that diffraction plays an important role in image formation in any photon-based lithographic system. Some of the consequences of diffraction are reduction in contrast of the aerial image and phenomenon such as line-end shortening. In this article we explore some computational schemes which modify the mask pattern so as to minimize the diffractional effects. Several papers have been written on this problem for the case of optical lithography. Here, we consider the case of x-ray lithography only.