Videonics MXPro DV, User Manual

Page: 184 / 198

MXP
RO
DV U
SER
G
UIDE
A
PPENDIX
C 176
V
IDEO
S
CALING
A
RTIFACTS
Reducing a video image’s size can create artifacts because some picture information
must be discarded to reduce the number of pixels in the image. In some cases, pic-
ture information might disappear when eliminating pixels. For example, lines in the
image might appear jagged when MXProDV removes pixels and, therefore, parts of
the line.
Some MXProDV transitions scale an image down gradually. This might cause small
features to appear and disappear as the image scales down.
The artifacts described here are normal when performing advanced effects. They are
normally minor when running transitions at normal speeds.
F
REEZE
Q
UALITY
You can set MXProDV to freeze either a frame or a field (see “Force Field Freeze” on
page 90).
Freeze Field captures one field (half a video frame) and duplicates it to make the two
fields that comprise a frame. This eliminates flashing caused when an object occupies
a different position in the two captured fields, or when an object is so small it appear
in only one field. MXProDV’s Field Freeze eliminates flashing artifacts but reduces
vertical resolution because it shows only one field.
Freeze Frame captures all fields in the image. This produces a higher quality image,
but some flashing might occur.
U
PSIDE
-D
OWN
V
IDEO
When you flip video upside-down (as occurs automatically with some transitions
and when using the Flip (vertical) option on the
INPUT EFFECTS
menu), the picture res-
olution reduces slightly to make the video image more stable. The reduction is subtle
with most video and most effects, especially those that move quickly.