Digital image enhancement techniques provide a multitude of choices for improving the visual quality of diagnostic images. Appropriate choice of such techniques is greatly influenced by the imaging modality, task at hand and viewing conditions. The principal objective of enhancement is to process a given image so that the result is more suitable than the original image for a specific application. This paper focuses on spatial domain techniques for radiographic image enhancement, with particular reference to intensity transformation methods, histogram equalization, neighborhood processing methods. The radiographic or x-ray image as an input image is subjected to the enhancement methods and enhanced image is obtained as output image. Signal detectability has been compared in terms of signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) to results obtained from the enhancement methods. Moreover, the proposed enhancement methods have been compared in terms of invariant moments, standard deviation and correlation coefficient.