Video Test Generator User Guide

626 Appendix B Image Reference
Dot_10, Dot_12, Dot_24
Description The active video area is filled with multiple rows of white, single pixel dots. The dots define
the corners of what would appear to be square boxes if all connecting pixels were lit. The
number of rows of boxes and the number of boxes per row depends on which version of
the image is selected and the screen aspect ratio of the currently-loaded format. The
number in the image’s name refers to the number of boxes that will be formed along the
minor axis for most aspect ratios. The generator calculates the ratio and then finds the
closest match from the following table.
The primary version has white pixel dots on a black background. A secondary version has
black pixel dots on a white background.
The primary version of the Dot_24 image is shown below.
Purpose To accurately produce an image on a color monitor, the three electron beams in the CRT
must meet (converge) at the same location at the same time. Small dots displayed on a
misconverged monitor appear as a group of multi-colored dots.
Aspect Ratio Dot_10 Dot_12 Dot_24
W : H
Decimal Number
of Rows
Boxes per
Row
Number
of Rows
Boxes per
Row
Number
of Rows
Boxes per
Row
16 : 9
1.777 É 10 16 10 16 18 32
5 : 3
1.666 É 10 16 10 16 18 30
4 : 3
1.333 É 10 14 12 16 24 32
1 : 1
1.000 10 10 12 12 24 24
3 : 4
0.750 14 10 16 12 32 24