The following terms are used when defining monitor specifications:

Digital Driving Level (DDL):
Digital control level (gray value) at the monitor input, usually a value of 0..255 for 8-bit systems or (rarely) 0..1023 for 10-bit systems. This value can often be determined interactively using the mouse pointer in the image with the image display software used.

Minimum Digital Driving Level (DDLmin):
Minimum digital control level at the input of the graphics card; the gray value 0 produces the minimum achievable luminance on the monitor.

Maximum Digital Driving Level (DDLmax):
Maximum digital drive level at the input of the graphics card, usually the value 255 for 8-bit systems or (rarely) 1023 for 10-bit systems. Here, the monitor pixel has its highest luminance.

Veiling luminance Lamb
Luminance generated by ambient light on the surface of a monitor; it is measured when the monitor is turned off.

Minimum display luminance Lmin
Minimum luminance at DDLmin, generated by the monitor and measured in the center of the image area. It includes the specific stray light of the test image used for the measurement, but not the veil luminance.

Maximum display luminance Lmax
Maximum luminance at DDLmax, generated by the image reproduction device and measured at the center of the monitor. It includes the specific stray light of the test image used for the measurement, but not the veil luminance.

Minimum luminance L'min
Luminance at the center of the monitor at DDLmin, the sum of the minimum display luminance and the haze luminance.

Maximum luminance L'max
Luminance at the center of the monitor at DDLmax, the sum of the maximum display luminance and the haze luminance.

Maximum luminance ratio r'
Ratio of maximum luminance L'max and minimum luminance L'min

Grayscale Standard Display Function (DICOM: Grayscale Standard Display Function, GSDF)
Mathematically defined assignment of incoming DDLs to luminance values of the monitor pixels based on the Barten model. This monitor characteristic curve describes the luminance response of the monitor system to the digital drive levels (DDL).

Ambient illuminance E
Illuminance is the ratio of luminous flux (lumens) to the illuminated area of the environment when the monitor is switched off; it is measured in lux [lx].

Image quality indicator (IQI)
Sets of wire IQIs, step-hole IQIs, or plates of thickness “T” with one to three holes (diameters 2T, 1T, and 4T).