12
Tracing
185
Tracing Parameters Description
The Options tab
Parameter
Description
Min Length
This parameter defines the size of the minimum raster object
that can be recognized.
Max Width
This parameter defines the maximum width of raster lines that
can be approximated by lines, arcs, circles, and polylines.
If the width of a raster line exceeds
Max Width
, then the only
possible mode is Auto tracing and approximating with an
outline object.
Max Break
Sets the length of the maximum ignored break in raster lines.
If a raster line is broken into parts and you want to trace this
line as an entire object, then set the value of
Max break
, than
largest interval between the raster line parts. The program will
ignore the breaks and create single vector object,
approximating the whole raster line. By setting a
comparatively large value of the parameter, you can, for
example, trace dash-dotted raster lines, and arcs as single
entities.
You can enter the values of
Min Length
,
Max width
and
Max
break
from the keyboard or measure them on the screen.
Approximation
Accuracy
This parameter determines the accuracy of approximating of
the original raster object with a vector one. If the original
image is distorted, for example, circles have the form of
ellipses, then you should reduce the value of the
Approximation Accuracy
parameter. However, this leads to
inaccuracies in recognition, for example, the program might
take a short arc for a line. When the quality of a raster image
is high, you can increase the value of the
Approximation
Accuracy
parameter.
Sometimes before tracing the quality of the raster image can
be improved by application of a smoothing filter.
Orthogonalization
If this option is on, then the tracing in
Auto
and
Line
modes
aligns created segments either perpendicular to or parallel
with the base direction. Providing the deviation of the original
object from these directions is insignificant. The base direction
is set in
Base angle
. The accepted deviation is determined
automatically by the
Approximation Accuracy
parameter value.
