close_edges
— Close edge gaps using the edge amplitude image.
close_edges(Edges, EdgeImage : RegionResult : MinAmplitude : )
close_edges
closes gaps in the output of an edge
detector, and thus tries to produce complete object contours. This
is done by examining the neighbors of each edge point to determine
the point with maximum amplitude (i.e., maximum gradient), and
adding the point to the edge if its amplitude is larger than the
minimum amplitude passed in MinAmplitude
. This operator
expects as input the edges (Edges
) and amplitude image
(EdgeImage
) returned by typical edge operators, such as
edges_image
or sobel_amp
.
close_edges
does not take into account the edge
directions that may be returned by an edge operator. Thus, in areas
where the gradient is almost constant the edges may become rather
“wiggly.”
Note that filter operators may return unexpected results if an image with a reduced domain is used as input. Please refer to the chapter Filters.
Edges
(input_object) region(-array) →
object
Region containing one pixel thick edges.
EdgeImage
(input_object) singlechannelimage →
object (byte / uint2 / int4)
Edge amplitude (gradient) image.
RegionResult
(output_object) region(-array) →
object
Region containing closed edges.
MinAmplitude
(input_control) integer →
(integer)
Minimum edge amplitude.
Default value: 16
Suggested values: 5, 8, 10, 12, 16, 20, 25, 30, 40, 50
Typical range of values: 1
≤
MinAmplitude
Minimum increment: 1
Recommended increment: 1
sobel_amp(Image,&EdgeAmp,"sum_abs",5); threshold(EdgeAmp,&EdgeRegion,40.0,255.0); skeleton(EdgeRegion,&ThinEdge); close_edges(ThinEdge,EdgeAmp,&CloseEdges,15); skeleton(CloseEdges,&ThinCloseEdges);
close_edges
returns 2 (H_MSG_TRUE) if all parameters are
correct. If the input is empty the behavior can be set via
set_system('no_object_result',<Result>)
. If
necessary, an exception is raised.
edges_image
,
sobel_amp
,
threshold
,
skeleton
close_edges_length
,
dilation1
,
closing
Foundation