Optimizing the image contrast on the softcopy displays

Cathode Ray Tube (CRT) displays and Active-Matrix Liquid Crystal Displays (AM-LCD) are currently the dominant softcopy displays in the radiology reading rooms. Results of some studies have shown the superiority of LCDs over CRTs in many aspects. In terms of the contrast resolution, however, they are similar and both of them can usually interpret 8-bit images. We have reported an error-diffusion-based method to compensate for the limited contrast resolution last year on this meeting. In this paper, we propose to include the image content into the error diffusion kernel to further increase the contrast of the image displayed. First, the raw image is processed to find the image contrast information. The areas in the image which have low contrast are enhanced more than the areas with high contrast. The areas where image noise is dominant are not enhanced. The enhancement operation will modify the image and the changes are treated as error and inputted to the error diffusion kernel. We have used a different set of diffusion weights for image contrast enhancement. But the two diffusion operations are done together.