NEC SpectraView II Guia Del Usuario página 34

33 | NEC SPECTRAVIEW II - USER'S GUIDE
since the low luminance can cause measurement errors that may cause artificially high Delta E values to be shown.
Selecting this option will cause all measured values to be included.
Show Average - shows the average Delta E value as a vertical line on the graph display.
Information window - DICOM Conformance tab
The DICOM Conformance tab shows graphically and numerically how well the calibrated display conforms to the ideal
DICOM (Digital Imaging and Communications in Medicine) response when a DICOM Target curve of is used.
The aim of the DICOM response is to have a perceptually linear luminance response. Each step along the display's
grayscale should have an equally perceptive increase in luminance. The actual shape of the DICOM response curve
is based on the display's measured Black Level and Intensity, since the DICOM response considers the human eye's
non-linear response to light.
In DICOM terminology, the grayscale level is called the Digital Driving Level and represents the digital output video
level, from 0 to 255. Each step in Digital Driving Level, should result in an equal step in perceived luminance. In DICOM
terminology, a change in luminance that is just perceptible, is considered to be 1 JND (Just Noticeable Difference).
So, ideally, each step in Digital Driving Level should result in an equal change in Just Noticeable Difference value. The
JND values are calculated using a complex formula from two measured luminance values.
The display calibration results can be viewed in two different types of graphs, JND per DDL, and Contrast Response,
by selecting the corresponding graph type.
JND per DDL (Just Noticeable Difference per Digital Driving Level)
Average - shows the average JND per DDL value. The actual value will depend on the Black Level and Intensity of
the display.
Std Dev - shows the standard deviation of all of the calculated JND per DDL values.