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KMID : 0354619940060020327
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Journal Dankook Dental Research Institute
1994 Volume.6 No. 2 p.327 ~ p.334
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The effect of exposure time on image density and contrast in digital radiography
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Abstract
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This study was performed to observe the effect of exposure time on the image density and contrast in digital radiography. Our digital imaging system was composed of Macintoch II ci computer, QuickCapture grabber board, Sony XC-77 CCD camera with
"NIH
Image" software Aluminum 10 step wedge frem 2mm to 20mm was exposed by Oramatic dental x-ray machine of 70kVp, 8mA. Ten exposure time groups from 0.06 second to 1.0 second were made.
Five films per each group were taken and processed. After all the films were digitize, gray values of each aluminum step were measured. And those were converted to image density by Martin's method and relative image contrast were calculated. It
found
that image density and contrast were increased when exposure time was increased.
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KEYWORD
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