Quantum Data 881, User Manual

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278 Chapter 9 Testing HDMI Sink Devices
measure of the saturation of the color. The central axis is achromatic (grayscale) and is
defined as 0 and the scale is arranged concentrically. The farther one moves away from
the center, the greater the saturation.
The steps are arranged such that the degree of differentiation between each step is
preceived to be equal. A value differential of 1 and a chroma differential of 2 are set up
such that they are preceived visually as having the same degree of difference.
The figure below depicts the Munsell Color System:
All colors in the Munsell color cascade can be mapped to the xvYCC color space but only
55% of these colors can be mapped to the sRGB color space.
The 882E instrument provides Munsell images for testing displays that support xvYCC
color space. The following images are used:
• MnslGM - This is a color checker image with 24 colors arranged in a checker board.
• MnslCLR - There are a series of these images (40 in total) that are accessible as sub
images through the 882E front panel. Each hue in the MnslCLR image set has 4 sub
hues, labeled 2.5, 5, 7.5 and 10, that represent a hue as it traverses around the
perimeter of the diagram above and transitions into the adjacent hues. Each such sub
image depicts the chroma and value variances of one of these sub hues. Each sub
image provides a color block for each chroma and value level for that sub hue. The
value varies along the vertical axis and the chroma varies along the horizontal axis.