This drop-down menu selects the source of the color value
displayed in the Readout. There are 10 sources (or "Registers") to
choose from, in three categories.
The first is the Current Measurement
value, and reflects the last measurement taken.
The second is the Reference Measurement,
the value used for most of the comparative Readouts such as delta
E's, Reading Delta's, RGB Adjustment Reading etc. This value is
set using the ->Ref. button on the Measurement View.
The remaining 8 sources are the 8 Primary
Color References. The Primary Color references are
used for a variety of purposes, the White and Black being used for
computing some Readout values. These values are set using the left
hand "store to Primary Reference" button on the Measurement View.
Typically most Readouts will be set to use the Current
Measurement value, but configuring a Readout to use a different
source is the means of examining the reference values. A Readout
set to use a Reference as a source also provides a means of
manually setting the reference value using the two finger
tap "Set a Readout Value" functionality.
To help organize the large number of possibly Readout types, they
are organized into categories. The category is selected using the
The Readout Type is then selected using the third drop-down menu. Each readout type may then have more detailed configuration options, and these are documented in the specific colorspace links below.
These are all derived from CIE XYZ tri-stumulus colorspaces.
|XYZ||CIE XYZ Color Space|
|Yxy||CIE 1931 Chromaticity Space|
(CIE 1976 UCS)
||Perceptually uniform Chromaticity space|
||CIELAB Perceptually uniform Color Space|
||Polar version of L*a*b* space|
||CIE 1976 Perceptually uniform Color Space|
||Polar version of L*u*v* space|
|DIN99 Lab||DIN99 Perceptually uniform Color Space|
These are component differences between the Reference Measurement
and the Current Measurement from the same CIE XYZ derived
|Delta XYZ||Component Differences of CIE XYZ Color Space|
|Delta Yxy||Component Differences of CIE 1931 Chromaticity Space|
|Delta Yu'v' (CIE 1976 UCS)||Component Differences of Perceptually uniform Chromaticity space|
|Delta L*a*b*||Component Differences of CIELAB Perceptually uniform Color Space|
|Delta L*C*h*ab||Component Differences of Polar version of L*a*b* space|
|Delta L*u*v*||Component Differences of CIE 1976 Perceptually uniform Color Space|
|Delta L*C*h*uv||Component Differences of Polar
version of L*u*v* space
|Delta DIN99 Lab||Component Differences of DIN99 Perceptually uniform Color Space|
A Delta E or Color Difference value is a single number that
represents the difference between two colors. Typically the idea
is that a Delta E of 1 is a just noticeable color difference.
Various delta E measures have been developed over the years,
reflecting increased sophistication in understanding of color, as
well as measures that are more appropriate to specific application
|CIE Delta E 76 (L*a*b* dE)||Eclidean difference between two L*a*b* values|
|CIE Delta E 94||More perceptually accurate version of CIE Delta E 76|
|CIE Delta E 94 Textile||Textile optimized version of CIE Delta E 94|
|CIE Delta E 2000||More perceptually accurate version of CIE Delta E 94|
|CMC Delta E 2:1||CMC 1984 modifed version of CIE Delta E 76 suitable for textile acceptability|
|CMC Delta E 1:1||CMC 1984 modified version of CIE Delta E 76 suitable for textile perceptibility|
|DIN99 Delta E||Euclidean difference between two DIN99 L99a99b99 values, comparable to CIE Delta E 2000|
A reflective or transmissive density is a logarithmic measure of
how much light is absorbed or blocked. A density measurement is
intended to suite a particular reproduction process, since it
typically aims to measure the amount of a colorant on the media.
To be able to match the standard density measures, a spectral
instrument is needed, since each standard varies in its spectral
response curves. Density is also the basis for measuring Tone
Value Increase (TVI, A.K.A. Dot Gain).
|Visual Density||Photopic luminous efficiency function
|Status A Density||Photographic Color Positive Print Density|
|Status M Density||Photographic Color Negative Print Density|
|Status T Density||U.S.A. Wide band Color Reflection Density|
|Status E (DIN) Density||European Wide band Color Reflection Density|
|ISO Type 1 & 2 Density||Diazo & Vesicular, Silver Halide Printing Density.|
||Tone Value Increase (A.K.A. Dot Gain)
These relate specifically to evaluating exposure, and calculating
|Exposure Value (EV)|
|Exposure Calculator||Interactive Shutter speed/Aperture/ISO/Exposure adjustment calculator.|
|Color Temperature||Correlated/Visual, Black Body/Daylight, Kelvin/Mired color temperature.|
|Delta Color Temperature||Difference in color temperature|
||Configurable RGB colorspace
||Delta Configurable RGB colorspace|
|RGB/CMY Adjustment||Direction to change an RGB or CMY value to reduce the Total color error or just Chromaticity error, to the reference measurement.|
|Web RGB||Conversion to Web Hex color value|
|Color Rendering Index (CIE 1995 Ra)||Measure of the color fidelity of a light source|
Lighting Consistency Index (EBU 2012)
||Measure the color fidelity of a light source
for Television use.
|Visual Contrast||Contrast ratio between measurement and reference.|
|ARPANSA UV Exposure||Australian Radiation Protection and Nuclear Safety Agency Ultraviolet Radiation exposure limits|
|Compare Swatches||Visual representation of the color of the measurement and reference.|
|Named Color||Name of the closest color from the selected named color library.|
|Named Color Swatch||Visual representation of the color of the measurement, and the closest color from the selected named color library to together wit its Name and delta E.|