NOISE CONTENT-ANALYSIS IN CLINICAL DIGITAL IMAGES

Most digital modalities in radiology use 12 bits precision to store th e digital images. To determine whether all these bits contain useful i nformation, a statistical method called the Moran test was used to mea sure the noise level in computed tomographic, magnetic resonance, and digital radiographic images. The test was performed on the bit planes of each pixel. After the noise level was estimated, the pixel data wer e separated into signal bits and noise bits, and image enhancement tec hniques were applied on the noise-bits-removed images to demonstrate t hat the removal of noise bits did not affect image quality. Preliminar y results showed no noticeable difference between the original images and the noise-bits-removed images.