This final chapter on display requirements considers requirements for noise, artifacts, and distortions. Noise represents unwanted luminance variation and can be defined in both the spatial and temporal domain. Artifacts can be considered a form of noise in that they interfere with the presentation of the image of interest. Distortions result from failures to geometrically control the spatial relationships in the image of interest. Noise and artifacts in particular can affect the ability to see small, low-contrast detail. Noise is of particular importance in the display of medical images that require the detection of small anomalies (tumors, fractures). Distortions are of lesser importance, primarily because they are so readily detectable and correctable. As in the previous two chapters, this chapter begins with a listing of requirements and their definitions. Justification for the requirements follows, along with procedures for measurement. Test targets are provided on the enclosed CD.
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