DVS Clipster User's Guide download pdf (Page 117)

5-7

The Control Area

mulation of dots in all three color components near the 0 % line (plus

headroom, if applicable). When playing out in RGB, this video scope

can be used to evaluate the color distribution of the output image ac-

curately.

YUV Parade

The YUV parade displays graphically the distribution of the compo-

nents Y, U and V separately. The Y graph is shown on the left side, while

the color difference signals U and V are displayed in the middle and to

the right. As with the RGB parade the output image is evaluated line by

line and for each line the distribution is shown.

Figure 5-9: The YUV parade

However, because U and V can take on negative as well as positive val-

ues their graphs usually are distributed around a center line. It can be

found in the middle of the YUV parade because in digital video an off-

set of 128 (for 8 bit data) is added to U and V to get rid of the negative

value. In case the output image is black and white only, U and V would

be zero (128) resulting in a flat line in the middle of their graphs. The

more the color saturation of an output image increases, the more the

two graphs would be dispersed. Values of U greater than 50 in the

graph indicate positive values and blue hues, while values of less than

50 indicate yellow hues and negative values. The same applies to V

with the exception that values greater 50 would indicate red hues, and

values less than 50 cyan hues. Regarding the luma signal Y a value of

zero indicates black, while a value of 100 represents white. Neverthe-

less, especially when working with YUV, a reserved headroom for all

components should be observed.

Waveform

The waveform video scope is similar to the RGB parade. It displays

graphically the distribution of the color components red, green, and

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DVS Clipster User's Guide Page 117