The Radiographic Image (II)
Unsharpness in a radiographic image is important when considering image quality but it should not be considered in isolation. Unsharpness can be measured ignoring image contrast but when the image is viewed it is image contrast which affects not only the visual appreciation of unsharpness but also the ease with which information is visually retrieved even in the absence of any unsharpness. No discussion of image quality would be complete without consideration of image contrast and the factors influencing it. The subject of image contrast has been mentioned several times previously but it is now time for a more detailed discussion. As an area of study, image contrast should not be divorced from other image quality factors such as unsharpness, resolution and noise, and cross-reference should continually be made to achieve an overall impression of the immensely complex subject of image quality.
KeywordsScattered Radiation Radiographic Image Linear Attenuation Coefficient Radiographic Contrast Brightness Difference
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