template<typename TSegmentComputer>
class DGtal::GreedySegmentation< TSegmentComputer >
Aim: Computes the greedy segmentation of a range given by a pair of ConstIterators. The last element of a given segment is the first one one of the next segment.
Description of template class 'GreedySegmentation'
This class is a model of CSegmentation.
- Template Parameters
-
| TSegmentComputer | at least a model of CForwardSegmentComputer (an online algorithm for the recognition of a given class of segments). |
In the short example below, a digital curve stored in a STL vector is decomposed into 8-connected DSSs whose parameters are sent to the standard output.
typedef PointVector<2,int> Point;
typedef std::vector<Point>
Range;
typedef GreedySegmentation<SegmentComputer> Segmentation;
curve.push_back(Point(1,1));
curve.push_back(Point(2,1));
curve.push_back(Point(3,2));
curve.push_back(Point(4,2));
curve.push_back(Point(5,2));
curve.push_back(Point(6,2));
curve.push_back(Point(7,2));
curve.push_back(Point(8,1));
curve.push_back(Point(9,1));
Segmentation theSegmentation(curve.
begin(), curve.
end(), recognitionAlgorithm);
Segmentation::SegmentComputerIterator i = theSegmentation.begin();
Segmentation::SegmentComputerIterator end = theSegmentation.end();
}
If you want to get the DSSs segmentation of the digital curve when it is scanned in the reverse way, you can use the reverse iterator of the STL vector:
...
typedef Range::const_reverse_iterator ConstReverseIterator;
...
Segmentation theSegmentation(curve.
rbegin(), curve.
rend(), recognitionAlgorithm);
...
If you want to get the DSSs segmentation of a part of the digital curve (not the whole digital curve), you can give the range to process as a pair of iterators when calling the setSubRange() method as follow:
theSegmentation.setSubRange(beginIt, endIt);
Obviously, [beginIt, endIt) has to be a valid range included in the wider range [curve.begin(), curve.end()).
Moreover, a part of a digital curve may be processed either as an independant (open) digital curve or as a part whose segmentation at the ends depends of the underlying digital curve. That's why 3 processing modes are available:
- "Truncate" (default), the extension of the last segment (and the segmentation) stops just before endIt.
- "Truncate+1", the last segment is extended to endIt too if it is possible, provided that endIt != curve.end().
- "DoNotTruncate", the last segment is extended as far as possible, provided that curve.end() is not reached.
In order to set a mode (before getting a SegmentComputerIterator),
use the setMode() method as follow:
theSegmentation.setMode("DoNotTruncate");
Note that the default mode will be used for any unknown modes.
- See also
- testSegmentation.cpp
- Examples:
- geometry/curves/exampleArithDSS3d.cpp, geometry/curves/exampleFrechetShortcut.cpp, geometry/curves/greedy-dss-decomposition.cpp, and geometry/curves/greedyAlphaThickDecomposition.cpp.
Definition at line 149 of file GreedySegmentation.h.
1.8.10
