/usr/share/doc/dx/help/dxall614 is in dx-doc 1:4.4.4-7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | #!F-adobe-helvetica-medium-r-normal--18*
#!N
#!CSeaGreen #!N #!Rall613 TV Line Resolution
#!N #!EC #!N #!N Resolution losses are most evident if you
use single-width lines. Workstations have both a higher number of vertical
and horizontal lines on the screen, and a much higher "refresh"
rate than consumer TV. However, on TV, the alternating lines (odd
numbered, even numbered) are "refreshed" or painted on the monitor at
slightly different times. As long as the scene contains objects that
span more than one of these lines, our eye-brain system is
fooled into believing that the entire object is always present, due
to the phenomenon of "persistence of vision." But when you use
single-line width horizontal lines, the lines will visibly flash, clearly showing
that they are being drawn only half of the time. #!N
#!N Related to this problem is the condition in which you
rotate a grid of single-width lines slightly away from horizontal. This
will generate an optical effect called a "moire pattern," in which
curved lines appear where none are actually present, and, this frequently
causes colors to appear that are not in the original signal.
Both of these effects can be very distracting. #!N #!N Finally,
single-width vertical lines will not have the same color! Because of
the way consumer TV color phosphors are aligned, a vertical line
at one location may be blue, but if you move it
slightly it will become red. A grid with single-width vertical lines
will appear to change color as you translate the grid in
a horizontal direction. #!N #!N So what is the solution to
all these problems? Do not use single-width lines, ever. Data Explorer's
Tube module is the easiest way to fix most of these
problems. Tube generates cylinders around any kind of field with line
connections. If you have created a mesh of lines with ShowConnections,
for example, you can run this visual object through Tube to
"fatten" up the lines. Tube permits you to choose a diameter
that looks right. As long as you make the tubed lines
bigger than one TV line width, you will have solved the
problem. #!N #!N Be aware that single-width line text or captions
will become virtually illegible on TV. To get better-looking results using
the "stroke" fonts (originally designed for plotters), you can use Tube.
Another technique is to use a multiple-line font, such as the
"roman_d" font supplied with Data Explorer. The best solution is to
use an "area" font that is made up of characters containing
polygonal faces rather than single lines. Data Explorer provides a font
called "area," or "pitman," which uses polygonal faces. #!N #!N Another
tip about text is that due to the much lower resolution
of TV, you must be careful to keep text large! Ideally,
use a size that permits only about 30 to 40 characters
to fit across the width of the screen. Fine detailed text
annotations may look good on the workstation, but will become blurry
little globs on TV, defeating the whole purpose of annotating your
video for your viewers. Try making some text in different sizes,
then dub to VHS videotape. Can you still read the text?
If so, the size is probably sufficient for general use. If
it is too mushy to read, increase the size. For best
legibility use white or yellow colored text. #!N #!N #!N #!F-adobe-times-medium-i-normal--18*
Next Topic #!EF #!N #!N #!Lall614,dxall615 h TV Color Resolution #!EL #!N #!F-adobe-times-medium-i-normal--18* #!N
|