[C#/WINFORM/EMGUCV] 도형 검출하기

■ 도형을 검출하는 방법을 보여준다.

▶ MainForm.cs


using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;

namespace TestProject
{
    /// <summary>
    /// 메인 폼
    /// </summary>
    public partial class MainForm : Form
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 생성자 - MainForm()

        /// <summary>
        /// 생성자
        /// </summary>
        public MainForm()
        {
            InitializeComponent();

            this.filePathTextBox.TextChanged += filePathTextBox_TextChanged;
            this.filePathButton.Click        += filePathButton_Click;

            this.filePathTextBox.Text = "sample.png";
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Private
        //////////////////////////////////////////////////////////////////////////////// Event

        #region 파일 경로 텍스트 박스 텍스트 변경시 처리하기 - filePathTextBox_TextChanged(sender, e)

        /// <summary>
        /// 파일 경로 텍스트 박스 텍스트 변경시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void filePathTextBox_TextChanged(object sender, EventArgs e)
        {
            DetectShape();
        }

        #endregion
        #region 파일 경로 버튼 클릭시 처리하기 - filePathButton_Click(sender, e)

        /// <summary>
        /// 파일 경로 버튼 클릭시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void filePathButton_Click(object sender, EventArgs e)
        {
            DialogResult result = this.openFileDialog.ShowDialog();

            if(result == DialogResult.OK || result == DialogResult.Yes)
            {
                this.filePathTextBox.Text = this.openFileDialog.FileName;
            }
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////// Function

        #region 도형 검출하기 - DetectShape()

        /// <summary>
        /// 도형 검출하기
        /// </summary>
        public void DetectShape()
        {
            if(this.filePathTextBox.Text != string.Empty)
            {
                StringBuilder stringBuilder = new StringBuilder("성능 : ");

                Image<Bgr, Byte> sourceImage = new Image<Bgr, byte>(this.filePathTextBox.Text).Resize(400, 400, INTER.CV_INTER_LINEAR, true);

                Image<Gray, Byte> grayscaleImage = sourceImage.Convert<Gray, Byte>().PyrDown().PyrUp();

                Stopwatch stopwatch = Stopwatch.StartNew();

                #region 원을 검출한다.

                double cannyThreshold             = 180.0;
                double circleAccumulatorThreshold = 120;

                CircleF[][] circleArray = grayscaleImage.HoughCircles
                (
                    new Gray(cannyThreshold),
                    new Gray(circleAccumulatorThreshold),
                    2.0,  // 원 중심 검출에 사용되는 누산기 해상도
                    20.0, // 최소 거리
                    5,    // 최소 반경
                    0     // 최대 반경
                );

                #endregion

                stopwatch.Stop();

                stringBuilder.Append(String.Format("원 - {0} 밀리초; ", stopwatch.ElapsedMilliseconds));

                stopwatch.Reset();

                stopwatch.Start();

                #region 선을 검출한다.

                double cannyThresholdLinking = 120.0;

                Image<Gray, Byte> cannyEdges = grayscaleImage.Canny(cannyThreshold, cannyThresholdLinking);

                LineSegment2D[][] lineArray = cannyEdges.HoughLinesBinary
                (
                    1,              // 거리 해상도 (픽셀 관련 단위)
                    Math.PI / 45.0, // 라디안으로 측정되는 각도 해상도
                    20,             // 한계점
                    30,             // 최소 선 너비
                    10              // 선간 간격
                );

                #endregion

                stopwatch.Stop();

                stringBuilder.Append(String.Format("선 - {0} 밀리초; ", stopwatch.ElapsedMilliseconds));

                stopwatch.Reset();

                stopwatch.Start();

                #region 삼각형과 사각형을 검출한다.

                List<Triangle2DF> triangleList = new List<Triangle2DF>();

                List<MCvBox2D> rectangleList = new List<MCvBox2D>();

                using(MemStorage storage = new MemStorage())
                {
                    for(Contour<Point> pointContour = cannyEdges.FindContours(CHAIN_APPROX_METHOD.CV_CHAIN_APPROX_SIMPLE, RETR_TYPE.CV_RETR_LIST, storage);
                        pointContour != null; pointContour = pointContour.HNext)
                    {
                        Contour<Point> currentContour = pointContour.ApproxPoly(pointContour.Perimeter * 0.05, storage);

                        if(currentContour.Area > 250)
                        {
                            if(currentContour.Total == 3) // 삼각형인 경우
                            {
                                Point[] pointArray = currentContour.ToArray();

                                triangleList.Add(new Triangle2DF(pointArray[0], pointArray[1], pointArray[2]));
                            }
                            else if(currentContour.Total == 4) // 사각형인 경우
                            {
                                #region 윤곽의 모든 각도가 [80, 100]도 이내인지 결정한다.

                                bool isRectangle = true;

                                Point[] pointArray = currentContour.ToArray();

                                LineSegment2D[] edgeArray = PointCollection.PolyLine(pointArray, true);

                                for(int i = 0; i < edgeArray.Length; i++)
                                {
                                    double angle = Math.Abs(edgeArray[(i + 1) % edgeArray.Length].GetExteriorAngleDegree(edgeArray[i]));

                                    if(angle < 80 || angle > 100)
                                    {
                                        isRectangle = false;

                                        break;
                                    }
                                }

                                #endregion

                                if(isRectangle)
                                {
                                    rectangleList.Add(currentContour.GetMinAreaRect());
                                }
                            }
                        }
                    }
                }

                #endregion

                stopwatch.Stop();

                stringBuilder.Append(String.Format("삼각형/사각형 - {0} 밀리초; ", stopwatch.ElapsedMilliseconds));

                Text = stringBuilder.ToString();

                this.originalImageBox.Image = sourceImage;

                #region 삼각형/사각형을 그린다.

                Image<Bgr, Byte> triangleRectangleImage = sourceImage.CopyBlank();

                foreach(Triangle2DF triangle in triangleList)
                {
                    triangleRectangleImage.Draw(triangle, new Bgr(Color.DarkBlue), 2);
                }

                foreach(MCvBox2D rectangle in rectangleList)
                {
                    triangleRectangleImage.Draw(rectangle, new Bgr(Color.DarkOrange), 2);
                }

                this.triangleRectangleImageBox.Image = triangleRectangleImage;

                #endregion
                #region 원을 그린다.

                Image<Bgr, Byte> circleImage = sourceImage.CopyBlank();

                foreach(CircleF circle in circleArray[0])
                {
                    circleImage.Draw(circle, new Bgr(Color.Brown), 2);
                }

                this.circleImageBox.Image = circleImage;

                #endregion
                #region 선을 그린다.

                Image<Bgr, Byte> lineImage = sourceImage.CopyBlank();

                foreach(LineSegment2D line in lineArray[0])
                {
                    lineImage.Draw(line, new Bgr(Color.Green), 2);
                }

                this.lineImageBox.Image = lineImage;

                #endregion
            }
        }

        #endregion
    }
}

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using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using Emgu.CV;

using Emgu.CV.CvEnum;

using Emgu.CV.Structure;

namespace TestProject

{

/// <summary>

/// 메인 폼

/// </summary>

public partial class MainForm : Form

{

//////////////////////////////////////////////////////////////////////////////////////////////////// Constructor

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 생성자 - MainForm()

/// <summary>

/// 생성자

/// </summary>

public MainForm()

{

InitializeComponent();

this.filePathTextBox.TextChanged += filePathTextBox_TextChanged;

this.filePathButton.Click += filePathButton_Click;

this.filePathTextBox.Text = "sample.png";

}

#endregion

//////////////////////////////////////////////////////////////////////////////////////////////////// Constructor

////////////////////////////////////////////////////////////////////////////////////////// Private

//////////////////////////////////////////////////////////////////////////////// Event

#region 파일 경로 텍스트 박스 텍스트 변경시 처리하기 - filePathTextBox_TextChanged(sender, e)

/// <summary>

/// 파일 경로 텍스트 박스 텍스트 변경시 처리하기

/// </summary>

/// <param name="sender">이벤트 발생자</param>

/// <param name="e">이벤트 인자</param>

private void filePathTextBox_TextChanged(object sender, EventArgs e)

{

DetectShape();

}

#endregion

#region 파일 경로 버튼 클릭시 처리하기 - filePathButton_Click(sender, e)

/// <summary>

/// 파일 경로 버튼 클릭시 처리하기

/// </summary>

/// <param name="sender">이벤트 발생자</param>

/// <param name="e">이벤트 인자</param>

private void filePathButton_Click(object sender, EventArgs e)

{

DialogResult result = this.openFileDialog.ShowDialog();

if(result == DialogResult.OK || result == DialogResult.Yes)

{

this.filePathTextBox.Text = this.openFileDialog.FileName;

}

#endregion

//////////////////////////////////////////////////////////////////////////////// Function

#region 도형 검출하기 - DetectShape()

/// <summary>

/// 도형 검출하기

/// </summary>

public void DetectShape()

{

if(this.filePathTextBox.Text != string.Empty)

{

StringBuilder stringBuilder = new StringBuilder("성능 : ");

Image<Bgr, Byte> sourceImage = new Image<Bgr, byte>(this.filePathTextBox.Text).Resize(400, 400, INTER.CV_INTER_LINEAR, true);

Image<Gray, Byte> grayscaleImage = sourceImage.Convert<Gray, Byte>().PyrDown().PyrUp();

Stopwatch stopwatch = Stopwatch.StartNew();

#region 원을 검출한다.

double cannyThreshold = 180.0;

double circleAccumulatorThreshold = 120;

CircleF[][] circleArray = grayscaleImage.HoughCircles

(

new Gray(cannyThreshold),

new Gray(circleAccumulatorThreshold),

2.0, // 원 중심 검출에 사용되는 누산기 해상도

20.0, // 최소 거리

5, // 최소 반경

0 // 최대 반경

);

#endregion

stopwatch.Stop();

stringBuilder.Append(String.Format("원 - {0} 밀리초; ", stopwatch.ElapsedMilliseconds));

stopwatch.Reset();

stopwatch.Start();

#region 선을 검출한다.

double cannyThresholdLinking = 120.0;

Image<Gray, Byte> cannyEdges = grayscaleImage.Canny(cannyThreshold, cannyThresholdLinking);

LineSegment2D[][] lineArray = cannyEdges.HoughLinesBinary

(

1, // 거리 해상도 (픽셀 관련 단위)

Math.PI / 45.0, // 라디안으로 측정되는 각도 해상도

20, // 한계점

30, // 최소 선 너비

10 // 선간 간격

);

#endregion

stopwatch.Stop();

stringBuilder.Append(String.Format("선 - {0} 밀리초; ", stopwatch.ElapsedMilliseconds));

stopwatch.Reset();

stopwatch.Start();

#region 삼각형과 사각형을 검출한다.

List<Triangle2DF> triangleList = new List<Triangle2DF>();

List<MCvBox2D> rectangleList = new List<MCvBox2D>();

using(MemStorage storage = new MemStorage())

{

for(Contour<Point> pointContour = cannyEdges.FindContours(CHAIN_APPROX_METHOD.CV_CHAIN_APPROX_SIMPLE, RETR_TYPE.CV_RETR_LIST, storage);

pointContour != null; pointContour = pointContour.HNext)

{

Contour<Point> currentContour = pointContour.ApproxPoly(pointContour.Perimeter * 0.05, storage);

if(currentContour.Area > 250)

{

if(currentContour.Total == 3) // 삼각형인 경우

{

Point[] pointArray = currentContour.ToArray();

triangleList.Add(new Triangle2DF(pointArray[0], pointArray[1], pointArray[2]));

}

else if(currentContour.Total == 4) // 사각형인 경우

{

#region 윤곽의 모든 각도가 [80, 100]도 이내인지 결정한다.

bool isRectangle = true;

Point[] pointArray = currentContour.ToArray();

LineSegment2D[] edgeArray = PointCollection.PolyLine(pointArray, true);

for(int i = 0; i < edgeArray.Length; i++)

{

double angle = Math.Abs(edgeArray[(i + 1) % edgeArray.Length].GetExteriorAngleDegree(edgeArray[i]));

if(angle < 80 || angle > 100)

{

isRectangle = false;

break;

}

#endregion

if(isRectangle)

{

rectangleList.Add(currentContour.GetMinAreaRect());

}

#endregion

stopwatch.Stop();

stringBuilder.Append(String.Format("삼각형/사각형 - {0} 밀리초; ", stopwatch.ElapsedMilliseconds));

Text = stringBuilder.ToString();

this.originalImageBox.Image = sourceImage;

#region 삼각형/사각형을 그린다.

Image<Bgr, Byte> triangleRectangleImage = sourceImage.CopyBlank();

foreach(Triangle2DF triangle in triangleList)

{

triangleRectangleImage.Draw(triangle, new Bgr(Color.DarkBlue), 2);

}

foreach(MCvBox2D rectangle in rectangleList)

{

triangleRectangleImage.Draw(rectangle, new Bgr(Color.DarkOrange), 2);

}

this.triangleRectangleImageBox.Image = triangleRectangleImage;

#endregion

#region 원을 그린다.

Image<Bgr, Byte> circleImage = sourceImage.CopyBlank();

foreach(CircleF circle in circleArray[0])

{

circleImage.Draw(circle, new Bgr(Color.Brown), 2);

}

this.circleImageBox.Image = circleImage;

#endregion

#region 선을 그린다.

Image<Bgr, Byte> lineImage = sourceImage.CopyBlank();

foreach(LineSegment2D line in lineArray[0])

{

lineImage.Draw(line, new Bgr(Color.Green), 2);

}

this.lineImageBox.Image = lineImage;

#endregion

}

#endregion

}

TestProject.zip