Dome CXtra, Руководство пользователя

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60 | Dome CXtra
Running the Monthly Quality Control Test
The monthly display calibration check is to ensure that the display
is calibrated and the brightness and contrast settings are at an
appropriate level for the reading of mammographic images on
the Dome display.
The calibration check was designed to be performed with the SMPTE
pattern built into the Dome CXtra software. Using any other pattern,
particularly a pattern that is displayed with another image viewer
tool, could result in failing the test and causing the display to be out
of compliance with test requirements.
You have the option to conduct this test in Normal or Expert mode.
Expert mode must be enable on the MQSA Test Configuration dialog.
To inspect display screen quality
When the SMPTE pattern appears on the display screen, examine the
image carefully for the following features:
• Verify that the 0%-5% contrast is visible.
• Verify that the 95%-100% contrast is visible.
• Verify that each gray level step from 0% to 100% can be
distinguished from the adjacent squares. Verify that you can,
for example, distinguish the 0% square from the 10% square or
the 90% square from the 100% square.
• Verify that the alphanumeric characters that appear on the pattern
are sharp and in focus. For example, examine the “%” signs that
label the steps of the gray scale.
• Verify that the high contrast line-pair images at the center and
corners of the SMPTE pattern are distinguishable.
NOTE: The SMPTE pattern shown via the Dome CXtra software has
five sets of high-contrast and five sets of low-contrast line-pair
patterns. One set of each is in the center of the image, and one set of
each is in each corner of the image. The high-contrast patterns have
frequencies of 3- pixels-on/3-pixels-off, 2-pixels-on/2-pixels-off, and
1-pixel-on/1-pixel-off. At each frequency, a set of line-pairs is
oriented in the horizontal direction and a set is oriented in the
vertical direction. Visibility of the low-contrast patterns is not
evaluated in this test.