Contour

Child-classe, implements OpenCV's contour finding. More...

#include <Contour.h>

Inheritance diagram for Contour:

Public Member Functions
	Contour (const cv::String name)
	Constructor. More...
void	setAction (void *data)
	sets the output of the action More...
void *	getAction ()
	gets the output of the action More...
void	showWindow ()
	shows the action to the user More...
Public Member Functions inherited from PipeLineAction
	PipeLineAction ()
	Default constructor.
	PipeLineAction (const cv::String name)
	Constructor. More...
void	hideWindow ()
	hides the action to the user More...
cv::String	getName ()
	gets the pipeline action name More...

Private Attributes
std::vector< std::vector< cv::Point > >	contours
	vector containing all contour points
std::vector< std::vector< cv::Point > >	polylines
	vector containing all polyline points
const cv::Scalar	green { 0,255,0 }
	color green
const cv::Scalar	red { 0,0,255 }
	color red
const int	accuracyMax = 20
	maximum value of the accuracy trackbar
const int	areaMax = 50
	maximum value of the area trackbar
int	accuracy
	current value of the accuracy trackbar
int	area
	area value of the accuracy trackbar

Additional Inherited Members
Protected Attributes inherited from PipeLineAction
cv::Mat	img
	Matrix which holds the image of the action.
bool	show
	Show action flag.
cv::String	name
	(screen)name of the pipeline action

Detailed Description

Child-classe, implements OpenCV's contour finding.

With area filtering and size sorting

Constructor & Destructor Documentation

Contour()

Contour::Contour

(

const cv::String

name

)

Constructor.

Parameters

name	(screen)name of mask action

                                    : PipeLineAction(name)
{
    accuracy = 3;
    area = 10;
}

Member Function Documentation

setAction()

void Contour::setAction ( void *  data )

virtual

sets the output of the action

Sets the action, in this case: finding all contours of the input matrix. And appying a area filter, bigger than the trackbar value multiplied by 10 contour color is green. Smaller countours are painted red. If there are no contours big enough, the vector is cleared.

Parameters

data	pointer to the input data, should be a OpenCV matrix

Implements PipeLineAction.

{
    Mat* d = static_cast<Mat*>(data);
    // Find Contours
    img = Mat(d->rows, d->cols, CV_8SC3);
    findContours(d->clone(), contours, RETR_TREE, CHAIN_APPROX_SIMPLE);
        
    if (contours.size() > 0) {
        //Draw contours
        polylines.resize(contours.size());
        bool areaBigEnough = false;
        Scalar lineColor;
        for (size_t i = 0; i < contours.size(); i++)
        {
 
            approxPolyDP(contours[i], polylines[i], accuracy, true);
            //Check area size
            if (contourArea(contours[i]) > area*100) {
                areaBigEnough = true;
                lineColor = green;
            }
            else {
                lineColor = red;
            }
            drawContours(img, polylines, (int)i, lineColor);
        }
        //Sort contours by size
        if (areaBigEnough) {
            sort(
                contours.begin(),
                contours.end(),
                [](const vector<Point>& a, const vector<Point>& b) { return a.size() < b.size(); }
            );
        }
        // Clear contour area
        else {
            contours.clear();
        }
    }
}

getAction()

void * Contour::getAction ( )

virtual

gets the output of the action

Returns

data: pointer to a vector with in a vector containing the points of all contours found

Reimplemented from PipeLineAction.

{
    return &contours;
}

showWindow()

void Contour::showWindow ( )

virtual

shows the action to the user

uses cv::imshow(). The name of the window is the name of the pipeline action. Trackbar is added to set the size of the approximation accuracy

Implements PipeLineAction.

{
    if (!show) {
        namedWindow(name);
        createTrackbar("Accuracy", name, &accuracy, accuracyMax);
        createTrackbar("Area factor", name, &area, areaMax);
        show = true;
    }
    imshow(name, img);
}