Polygon¶

class Polygon(*args, **kwargs)¶

Bases: pybind11_object

Defines a generic 2D polygon.

A polygon is internally represented by N 2D points.

By default three coordinates in the \((i,j)\) frame (see vpImagePoint class documentation for more details about the frame) are used \((0,0)\) , \((1,0)\) and \((0,1)\) .

The code bellow shows how to manipulate a polygon.

#include <iostream>

#include <visp3/core/vpPolygon.h>

#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif

int main()
{
  std::vector<vpImagePoint> corners;

  // Initialize the corners vector with 4 points
  corners.push_back( vpImagePoint( 50, 100) );
  corners.push_back( vpImagePoint( 50, 300) );
  corners.push_back( vpImagePoint(200, 300) );
  corners.push_back( vpImagePoint(200, 100) );

  // Initialize a polygon with the corners
  vpPolygon polygon(corners);

  // Get the polygon bounding box
  vpRect bbox = polygon.getBoundingBox();
  std::cout << "Bounding box: " << bbox.getTopLeft() << " to "
            << bbox.getBottomRight() << std::endl;

  // Get the polygon surface and center
  std::cout << "Area: " << polygon.getArea() << std::endl;
  std::cout << "Center: " << polygon.getCenter() << std::endl;

  // Check if a point is inside the polygon
  vpImagePoint ip(550, 200);
  std::cout << "The point " << ip << " is "
            << (polygon.isInside(ip) ? "inside":"outside")
            << " the polygon" << std::endl;

  return 0;
}

Overloaded function.

__init__(self: visp._visp.core.Polygon) -> None

Default constructor that creates an empty polygon.

__init__(self: visp._visp.core.Polygon, corners: list[visp._visp.core.ImagePoint]) -> None
__init__(self: visp._visp.core.Polygon, corners: list[visp._visp.core.ImagePoint]) -> None
__init__(self: visp._visp.core.Polygon, poly: visp._visp.core.Polygon) -> None

Copy constructor

Parameters:

poly: The polygon used for the initialisation.

Methods

`__init__`	Overloaded function.
`buildFrom`	Overloaded function.
`display`	Display the polygon in the image (overlay, so the image is not modified).
`getArea`	Return the area of the polygon.
`getBoundingBox`	Return the bounding box.
`getCenter`	Return the center of the polygon.
`getCorners`	Get the corners of the polygon.
`getSize`	Return number of corners belonging to the polygon.
`initClick`	Overloaded function.
`isInside`
`isInsideFromPoints`

Inherited Methods

Operators

`__doc__`
`__init__`	Overloaded function.
`__module__`

Attributes

`PnPolyRayCasting`
`PnPolySegmentIntersection`
`__annotations__`

class PointInPolygonMethod(self, value: int)¶

Bases: pybind11_object

Values:

PnPolySegmentIntersection: Legacy Point In Polygon test.
PnPolyRayCasting: Point In Polygon test using ray casting method (faster).

__and__(self, other: object) → object¶

__eq__(self, other: object) → bool¶

__ge__(self, other: object) → bool¶

__getstate__(self) → int¶

__gt__(self, other: object) → bool¶

__hash__(self) → int¶

__index__(self) → int¶

__init__(self, value: int)¶

__int__(self) → int¶

__invert__(self) → object¶

__le__(self, other: object) → bool¶

__lt__(self, other: object) → bool¶

__ne__(self, other: object) → bool¶

__or__(self, other: object) → object¶

__rand__(self, other: object) → object¶

__ror__(self, other: object) → object¶

__rxor__(self, other: object) → object¶

__setstate__(self, state: int) → None¶

__xor__(self, other: object) → object¶

property name : str¶

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: visp._visp.core.Polygon) -> None

Default constructor that creates an empty polygon.

__init__(self: visp._visp.core.Polygon, corners: list[visp._visp.core.ImagePoint]) -> None
__init__(self: visp._visp.core.Polygon, corners: list[visp._visp.core.ImagePoint]) -> None
__init__(self: visp._visp.core.Polygon, poly: visp._visp.core.Polygon) -> None

Copy constructor

Parameters:

poly: The polygon used for the initialisation.

buildFrom(*args, **kwargs)¶

Overloaded function.

buildFrom(self: visp._visp.core.Polygon, corners: list[visp._visp.core.ImagePoint], create_convex_hull: bool = false) -> visp._visp.core.Polygon

Initialises the triangle thanks to the collection of 2D points (in pixel).

Warning

the corners must be ordered (either clockwise or counter clockwise).

Parameters:

corners: The corners of the polygon.
create_convex_hull: Create a convex hull from the given corners.

buildFrom(self: visp._visp.core.Polygon, corners: list[visp._visp.core.ImagePoint], create_convex_hull: bool = false) -> visp._visp.core.Polygon

Initialises the polygon thanks to the collection of 2D points (in pixel).

Warning

the corners must be ordered (either clockwise or counter clockwise).

Parameters:

corners: The corners of the polygon.
create_convex_hull: Create a convex hull from the given corners.

buildFrom(self: visp._visp.core.Polygon, corners: list[visp._visp.core.Point], cam: visp._visp.core.CameraParameters, create_convex_hull: bool = false) -> visp._visp.core.Polygon

Initialises the triangle thanks to the collection of 2D points (in meter). The fields x and y are used to compute the corresponding coordinates in pixel thanks to the camera parameters cam .

Warning

the corners must be ordered (either clockwise or counter clockwise).

Parameters:

corners: The corners of the polygon.
cam: The camera parameters used to convert the coordinates from meter to pixel.
create_convex_hull: Create a convex hull from the given corners.

display(self, I: visp._visp.core.ImageGray, color: visp._visp.core.Color, thickness: int = 1) → None¶

Display the polygon in the image (overlay, so the image is not modified). A call to the flush() method is necessary.

Parameters:

I: visp._visp.core.ImageGray¶: The image where the polygon is displayed.
color: visp._visp.core.Color¶: The color of the polygon’s lines.
thickness: int = 1¶: The thickness of the polygon’s lines.

getArea(self) → float¶

Return the area of the polygon. The area is computed when the polygon is built from the corners.

Returns:: The area of the polygon.

getBoundingBox(self) → visp._visp.core.Rect¶

Return the bounding box. The bounding box is the smallest rectangle containing all the polygon.

Returns:: The bounding box of the polygon.

getCenter(self) → visp._visp.core.ImagePoint¶

Return the center of the polygon. The center is computed when the polygon is built from the corners.

Returns:: The area of the polygon.

getCorners(self) → list[visp._visp.core.ImagePoint]¶

Get the corners of the polygon.

Returns:: A reference to the corners.

getSize(self) → int¶: Return number of corners belonging to the polygon.

initClick(*args, **kwargs)¶

Overloaded function.

initClick(self: visp._visp.core.Polygon, I: visp._visp.core.ImageGray, size: int = 5, color: visp._visp.core.Color = vpColor::red, thickness: int = 1) -> None

Initialises the polygon by (left-)clicking to add a corners to the polygon. A right click is used to stop the addition of new corners.

Parameters:

I: The image where to click to initialise the corners.
size: Cross size in terms of number of pixels that is displayed over a polygon corner.
color: Color used to display the cross over the polygon corner.
thickness: Thickness used to display the cross.

initClick(self: visp._visp.core.Polygon, I: visp._visp.core.ImageRGBa, size: int = 5, color: visp._visp.core.Color = vpColor::red, thickness: int = 1) -> None

Initialises the polygon by (left-)clicking to add a corners to the polygon. A right click is used to stop the addition of new corners.

Parameters:

I: The image where to click to initialise the corners.
size: Size of the cross in terms of number of pixels that is displayed over a polygon corner.
color: Color used to display the cross over the polygon corner.
thickness: Thickness used to display the cross.

isInside(self, iP: visp._visp.core.ImagePoint, method: visp._visp.core.Polygon.PointInPolygonMethod = PnPolyRayCasting) → bool¶

static isInsideFromPoints(roi: list[visp._visp.core.ImagePoint], i: float, j: float, method: visp._visp.core.Polygon.PointInPolygonMethod = PnPolyRayCasting) → bool¶