Extron Electronics VTG 400D_400 DVI User Guide - Manual (Page 73)

A-9 VTG 400D/400 DVI • Appendix
4. 16:9 Crop (4:3 rates)
This test pattern is used to display the resulting letterbox effect of a
widescreen (16:9) image within a standard 4:3 display system. The
outer border corresponds to the maximum dimensions of a 4:3 image
for the given line rate. The two horizontal lines within the pattern
show the area and boundaries of a 16:9 image within a 4:3 space. Use this pattern
for setting or creating screen masking systems.
4:3 Crop (16:9 rates)
This test pattern is used to display the resulting side-boxing effect
of a standard 4:3 image within a 16:9 widescreen display system.
The outer border corresponds to the maximum dimensions of a
16:9 image for the given line rate. The two vertical lines within the
pattern show the area and boundaries of a 4:3 image within a 16:9 image space. Use
this pattern for setting or creating screen masking systems.
5. Rectangle/Square Crosshairs
This pattern can be used to properly center the image and set
geometry. For CRT-based projectors, this pattern is used to check and
adjust gross linearity and static convergence. Regardless of whether
the VTG is set for a 4:3 or 16:9 aspect ratio, this pattern provides a
perfectly centered square, which is useful for basic geometric alignment of the
projector and the projector-to-screen relationship.
Orthogonal alignment of the projector to the screen is critical for best overall focus
and image geometry. Utilizing a simple square allows the installation technician to
easily measure from the projector’s lens axis location to each corner of the test
square for determination of orthogonal alignment. In addition, the outer line
provides a border indicating the extreme boundary of the image. It is important
that the border line be just visible inside the screen boundaries. The crosshair lines
through the center of the pattern provide an easy target for static convergence
adjustment of a CRT projector or evaluation of video delay skew.
6. 4x4 Crosshatch
Crosshatch patterns are traditionally used for linearity and
convergence adjustment (both static and dynamic) of CRT-based
displays. Additionally, this particular 4 x 4 pattern is useful for
calibrating the position of picture-in-picture display boxes. It may
also be used to calibrate the division of the screen for multiplexed images such as in
video wall applications or video multiplexing processors handling several images
simultaneously.
7. Coarse Crosshatch
Crosshatch patterns are traditionally used for linearity and
convergence adjustment (both static and dynamic) of CRT-based
displays. The coarse crosshatch pattern may be appropriate for
adjustment where more points of interest are required for optimum
adjustment of large projected images. It may also be used for critical skew
alignment of the red, blue, and green signals within a twisted-pair video
transmission system.
Crosshatch patterns are typically generated using one-pixel wide vertical lines
(highest frequency in a given scan rate) and one-line wide horizontal lines in the
vertical scanning domain. This feature makes the pattern useful for measuring high