Tektronix RSA6100A Series, Help Manual

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General Signal Viewing > DPX Spectrum DPX Primer
When the Auto Color button is selected, the Maximum control’s value is set to the highest pixel value
in the current bitmap, shown in Figure 9. Now none of the available colors remain unused. The entire
palette is mapped to the occurrence values present at the time the button is selected, providing better
visual resolution for low densities. Selecting the Autoscale button in the DPX display scales all three
axes based on current results.
Figure 9. The Auto Color function optimizes the color scale settings.
Color Mapping Curves
The mapping between z-axis values and color does not have to be linear. The Curve control lets you
choose the shape of the mapping equation. A Curve setting of 1 selects the straight-line relationship.
Higher Curve numbers pull the curve upwards and to the left, concentrating color resolution on lower
densities. Settings less than 1 invert the curve, moving the focus of the color range towards higher density
values. Figure 10 shows the mapping curves.
Figure 10. Representative color mapping curves for the “Temperature” palette.
Using the same signal shown in Figures 8 and 9, the impact of the Curve control can be observed. With
the Curve control set to 1 in the Scale tab, shown in Figure 11, the mapping between color and density is
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RSA6100A Series Real-Time Spectrum Analyzers Help