Brightness and Contrast:
The brightness and contrast of your
monitor are adequately set if the 5% squares at both ends of gray scale
are visible.
Using the pattern: The gray scale is
shown as a series of squares in the center of the image that range from
black (0%) to white (100%) in a semi-rectangle. The 0% and 100% squares
(see arrows on image at left) each contain smaller squares within them
that represent signal level steps of 5% and 95%, respectively. You
should be able to visually differentiate the inner square from the
larger square that contains it.
Be aware that it may be
impossible to adjust your monitor to show both of these inner squares
perfectly and equally. Most video monitors do better in showing the 95%
square than the 5% square. However, you might see if reducing ambient
light improves the visibility of the 5% square.
Spatial Resolution and Aliasing:
The spatial resolution (linearity) and aliasing (distortion) of your
monitor are within acceptable limits if the high contrast bar patterns
in the test image are distinct as simple patterns of black and white
pairs.
Using the pattern: In
each corner of the image as well as in the very center (see arrows on
image at left), inspect the 6 squares filled with varying widths of
alternating black/white horizontal and vertical lines. You should be
able to differentiate all the lines, from fat to narrow (6 pixels, 4
pixels, and 2 pixels) and both horizontally and vertically.
Continuous Gray
Scale:
This test pattern is a continuous gray scale image from the center
of the pattern. Using the pattern:
No concentric ring-like features should be present. If such features are
present, the images displayed on your system will be displayed at less
than optimal quality.
SMPTE
Color Bar
SMPTE color bars are used
to set a variety of controls on a monitor such as black level, hue
and color saturation.
Note the order of Gray,
Yellow, Cyan, Green, Magenta, Red, and Blue from left to right. If any
of these colors are reversed on the screen, check for switched RGB
cables. If the colors are off when using composite or S-Video. then
adjust the HUE and COLOR controls on the monitor for proper colors. Note
that on many monitors, not all colors will look 100% correct, usually
yellow will be a different shade.
The -I and Q are colors just
off from blue (-I is toward green) and (Q is toward red). These are
typically used for factory measurements and may appear different in RGB
vs NTSC/YC.
-4, 0, and +4 are used for
setting brightness on video monitors. When set properly, only the +4 bar
should be visible while the -4 and 0 both appear black.
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