Diapositive 1

Scanner homogeneity

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Pixel value varies with position on the scanner plate due

to light scattering differences:

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small effects (<1%) when moving films parallel to

scan direction

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up to 8% variation when moving films perpendicular

to the scan direction, dose dependent.

<2% within 5 cm from the scanner axis for

D<2Gy)

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2D correction for “full” films

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Dose dependent

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Scanner dependent

EPSON Pro 1680 Expression scanner:

Paelinki et al PMB 52 (2007) and Fuss et al PMB 52 (2007)

Fiandra et al MP 33 (2006)

Epson 10000XL scanner

Ferreira et al. PMB54 (2009)

Scan direction

0,9273

0,9891

0,9859

0,9237

0,9992

0,9939

0,9933

1,0001

position

relative

pixel value

Scan direction