OmniTek OTR 1001, User Manual

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OmniTek OTR 1001 User Guide, v3.1 H-1
H : DCI Support
This section describes the additional image analysis displays that become available when the
VIEW_XR_DCI option is installed. Adding this option also adds support for the XYZ colour
space and for 12-bit pixel data.
H.1 CIE Colour Chart (Not available in PQA Mode)
The CIE Colour Chart is an x , y plot of the chrominance of each pixel as represented in XYZ
colour space, presented as a trace drawn over a standard background. The enclosed area within
this background indicates the full range of X,Y values that correspond to colours which are
visible to the human eye. In one version of the display, this area is also coloured to indicate the
colours represented by the different X,Y values.
Figure H-1: CIE Colour Chart
The chart has some special properties compared to other measures such as gamut charts,
histograms or the vectorscope. In particular:
Each colour that the eye can see is represented by a single point on the chart.
The point representing a colour is independent of the colour primaries that will be used to
display the colour.
It is also independent of the luminance.
The colours that can be reproduced by any set of three display primaries all lie within the
triangle formed by linking the points representing the colours of the individual primaries.
The CIE Colour Chart is of particular value in assessing the effect on the colour depth of video
generated for transmission in SD or HD from Digital Cinema source material, because the RGB
primaries specified for the DCI Reference Projector define a noticeably wider colour range than
can be produced with the display primaries specified for SD and HD. (There are also differences
between the colour ranges supported by the display primaries defined for PAL, NTSC and HD
but these differences are significantly smaller than those between these primaries and those
defined for Digital Cinema.)