Search results for "Contrast perception"

Contrast perception in digitized panoramic radiographs compared with their film-based origin

2002

Abstract Objectives. We sought to compare the visual image quality of film-based and digitized panoramic radiographs through use of a hole-containing test wedge. Study Design. An aluminum wedge containing 100 cells, of which 90 were given shallow holes, was exposed in the film-based Orthophos CD panoramic unit. Two radiographs subjectively exhibiting optimum contrast were selected. Films were digitized with a charge-coupled device flatbed scanner at 300 dpi. Films and digitized images were rated cellwise by 2 similar groups of 50 observers each with respect to spot perception. Results. The mean sensitivity was 0.26 ± 0.09 for film and 0.20 ± 0.07 for digitized images (P =.000), with a prono…