latest version v1.9 - last update 24 Nov 2005

lti::borderPoints Class Reference
[Aggregate Data Types, Shape Analysis]

Contour classes: Border-Points. More...

#include <ltiContour.h>

Inheritance diagram for lti::borderPoints:

[legend]Collaboration diagram for lti::borderPoints:

[legend]List of all members.

Public Member Functions
	borderPoints ()
	borderPoints (const borderPoints &other)
virtual	~borderPoints ()
const char *	getTypeName () const
borderPoints &	castFrom (const areaPoints &theAreaPoints)
borderPoints &	castFrom (const ioPoints &theIOPoints)
borderPoints &	castFrom (const polygonPoints &thePolygonPoints)
borderPoints &	castFrom (const polygonPoints &thePolygonPoints, const int &segments)
borderPoints &	operator= (const borderPoints &other)
bool	getFromMask (const channel8 &mask)
bool	generateMask (channel8 &mask, const bool computeBoundary=true, const bool exactBoundaryDimensions=false, const bool keepMaskData=false) const
void	invert ()
bool	isConsistent () const

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Detailed Description

Contour classes: Border-Points.

For the explanation of the contour description in this class, see following image:

   -- 00000000001111111111222222222233
   -- 01234567890123456789012345678901
   00 --------------------------------
   01 --------------------------------
   02 --------------------------------
   03 --------BBBB------BBBB----------
   04 -------B****BBB----B**B---------
   05 -------B*******B---B***B--------
   06 ------B*******B-----B*B---------
   07 -------B*******BBBBB**B---------
   08 ---------B*************B--------
   09 --------B**----*********B-------
   10 --------B**-----********B-------
   11 -------B**-----*******BB--------
   12 ------B**-----*******B----------
   13 ------B**-------******BB--------
   14 -----B**---------*******B-------
   15 -----B**--------*********B------
   16 ----B**-------**********BB------
   17 ---B***----*******----BB--------
   18 ----BBBBBBBBB***  --*B----------
   19 -------------BBBBBBBB-----------
   20 --------------------------------
   21 --------------------------------
   22 --------------------------------
   23 --------------------------------

  "-" means background and the rest is part of the object.
  "B" indicates a borderpoint.

This contour class allows three representations of a contour:

• IO-Points. It contains all input and output points for each line. For example, for the previous image: (8,3)(11,3)(18,3)(21,3)(7,4)(14,4)(19,4)(22,4)... Note that every IO-point is a border point, but not all border points are IO-points.
• Border Boints. It contains a list of the points at the border. Beginning with the point at (8,3) the chain code for our example image is: (8,3)(9,3)(10,3)(11,3)(12,4)(13,4)(14,4)(15,5)(14,6)...
• Area-Points. It contains all points in the object.

See also:

lti::ioPoints, lti::areaPoints

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Constructor & Destructor Documentation

lti::borderPoints::borderPoints (   )

default constructor creates an empty border-point-list

lti::borderPoints::borderPoints (  const borderPoints &  other  )

create this pointList as a copy of another pointList Parameters: other  the pointList to be copied.

virtual lti::borderPoints::~borderPoints (   )  [virtual]

destructor

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Member Function Documentation

borderPoints& lti::borderPoints::castFrom (  const polygonPoints &  thePolygonPoints, const int &  segments )

creates this borderPoint-List from the given PolygonPoint-List interpolating the curve with a cubicspline. Parameters: thePolygonPoints  polygon points with source data segments  each space between 2 polygonPoints is parted in segments lines. Returns: a reference to this object

borderPoints& lti::borderPoints::castFrom (  const polygonPoints &  thePolygonPoints  )

creates this borderPoint-List from the given PolygonPoint-List conecting the points with lines Parameters: thePolygonPoints  polygon points with source data Returns: a reference to this object

borderPoints& lti::borderPoints::castFrom (  const ioPoints &  theIOPoints  )

creates this io-list from the given io-point-list

borderPoints& lti::borderPoints::castFrom (  const areaPoints &  theAreaPoints  )

creates this border-point-list from the given area-point-list

bool lti::borderPoints::generateMask (  channel8 &  mask, const bool  computeBoundary = true, const bool  exactBoundaryDimensions = false, const bool  keepMaskData = false )  const

generate mask from border-points. The dimensions of the resulting mask are the smallest rectangle to contain the point (0,0) (optional) and all points in this list, plus 1 pixel in both width and heigth. If the boundary of the point list is not up to date, it can be calculated if specified in the parameters: Parameters: mask  The calculated mask will be stored here computeBoundary  If false, the internal boundary of the point list will be used, otherwise the boundary will be calculated (but NOT updated!!!). exactBoundaryDimensions  If true, the dimensions of the resulting mask will be the smallest rectangle to contain only the points in this list. The origin (0,0) may not be included, therefore a 1:1 correspondence of coordinates will generally not be given. keepMaskData  if false, the mask will be initialized with zero before getting the area mask. If true, the previous mask data is not deleted, but the mask will be resized if necessary. Returns: true if successful, false otherwise.

bool lti::borderPoints::getFromMask (  const channel8 &  mask  )

generate a border-point-list from the given mask image. This function assumes that the mask contains JUST ONE connected object. To get the biggest object on the mask see the lti::objectsFromMask functor.

const char* lti::borderPoints::getTypeName (  void   )  const [inline, virtual]

returns the name of this class: "borderPoints" Reimplemented from lti::tpointList< T >.

void lti::borderPoints::invert (   )

invert the direction of the border points

bool lti::borderPoints::isConsistent (   )  const

Check consistency of border points. Border points are consistent if the D8 distance between any two subsequent points (with the first point being subsequent to the last) is exactly 1, i.e. if every border point is "next to" its predecessor, with "next to" meaning "one of the 8 neighbouring pixels in the grid".

borderPoints& lti::borderPoints::operator= (  const borderPoints &  other  )  [inline]

assigment operator (alias for copy(other)). Parameters: other  the pointList to be copied Returns: a reference to the actual pointList

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The documentation for this class was generated from the following file:

• ltiContour.h

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