Quantum Data 881 - Manual (Page 1207)

881/882 Video Test Generator User Guide (Rev A.22) 1091
• The remaining central 8% of the image contains a row of chroma set bars. These bars
are part of the SMPTE pattern but are not in the EIA pattern. The order of the alternating
color and black bars matches those in the SMPTE pattern.
Test Color video performance
Purpose This general purpose pattern can be used to check the video handling capabilities of most
parts of a television system.
Method When viewed on a TV screen, all of the upper color bars should be correct and in the
order shown. The hue and intensity of each bar should be uniform over the entire bar.
The image can be used with a TV waveform analyzer to check the performance of a video
system. The upper color bars, as they would appear on a waveform analyzer, are shown
on a previous page.
Test Color decoder performance
Purpose The image can used with a TV vectorscope to check for proper operation of a video color
decoder. Vectorscope signatures of the upper and lower portions of the image using
NTSC encoding can be found on the previous page.
Method The vectorscope signature for the color bars should hit the target test point for each color
on the vectorscope’s graticule. If you are using PAL encoded video, the signature will be
similar to the one shown for the TVBar_75 test image on page page 1098.
The three “legs” of the vectorscope signature for the -I and Q color difference signals
should match the Burst, -I and Q reference lines on the vectorscope’s graticule.
The following tests are based on the original SMPTE guideline: