public static Emgu.CV.Util.VectorOfPoint ToClockwise(this Emgu.CV.Util.VectorOfPoint vectorOfPoint)
{
var array = new List <Point>(vectorOfPoint.ToArray());
array.Reverse();
if (Emgu.CV.CvInvoke.ContourArea(vectorOfPoint, true) < 0)
{
return(new Emgu.CV.Util.VectorOfPoint(array.ToArray()));
}
return(vectorOfPoint);
}
public static Point[] findCutPoint(Emgu.CV.Util.VectorOfPoint contours)
{
Point[] con1 = contours.ToArray();
Array.Sort(con1, compareY);
int size = con1.Length;
int top_x = con1[0].X;
int top_y = con1[0].Y;
int bottom_x = con1[size - 1].X;
int bottom_y = con1[size - 1].Y;
int top_x_count = 1;
int bottom_x_count = 1;
int flag1 = 0;
for (int i = 1; i < size / 10; i++)
{
if (top_y == con1[i].Y)
{
flag1 = 1;
top_x_count += 1;
top_x += con1[i].X;
}
if (bottom_y == con1[size - 1 - i].Y)
{
flag1 = 1;
bottom_x_count += 1;
bottom_x += con1[size - 1 - i].X;
}
if (flag1 == 0)
{
break;
}
}
float top_x_temp = (float)(top_x * 1.0F / top_x_count * 1.0);
float bottom_x_temp = (float)(bottom_x * 1.0F / bottom_x_count * 1.0);
Point[] con2 = con1;
Array.Sort(con2, compareX);
int left_x = con2[0].X;
int left_y = con2[0].Y;
int right_x = con2[size - 1].X;
int right_y = con2[size - 1].Y;
int left_y_count = 1;
int right_y_count = 1;
int flag2 = 0;
for (int i = 1; i < size / 10; i++)
{
if (left_x == con2[i].X)
{
flag2 = 1;
left_y_count += 1;
left_y += con2[i].Y;
}
if (right_x == con2[size - 1 - i].X)
{
flag2 = 1;
right_y_count += 1;
right_y += con2[size - 1 - i].Y;
}
if (flag2 == 0)
{
break;
}
}
float left_y_temp = left_y * 1.0F / (float)(left_y_count * 1.0F);
float right_y_temp = right_y * 1.0F / (float)right_y_count * 1.0F;
System.Drawing.Point[] p1 = new Point[4];
p1[0].X = (int)top_x_temp;
p1[0].Y = top_y;
p1[1].X = right_x;
p1[1].Y = (int)right_y_temp;
p1[2].X = (int)bottom_x_temp;
p1[2].Y = bottom_y;
p1[3].X = left_x;
p1[3].Y = (int)left_y_temp;
return(p1);
}
private void button2_Click(object sender, EventArgs e)
{
Image triangleRectangleImageBox1;
Image circleImageBox1;
Image lineImageBox1;
StringBuilder msgBuilder = new StringBuilder("Performance: ");
Bitmap clip_bmp = new Bitmap(cliped_image);
//Load the image from file and resize it for display
Image <Bgr, Byte> img = new Image <Bgr, byte>(clip_bmp).Resize(400, 400, Emgu.CV.CvEnum.Inter.Linear, true);
//Convert the image to grayscale and filter out the noise
UMat uimage = new UMat();
CvInvoke.CvtColor(img, uimage, ColorConversion.Bgr2Gray);
//use image pyr to remove noise
UMat pyrDown = new UMat();
CvInvoke.PyrDown(uimage, pyrDown);
CvInvoke.PyrUp(pyrDown, uimage);
#region circle detection
Stopwatch watch = Stopwatch.StartNew();
double cannyThreshold = 180.0; // 180
double circleAccumulatorThreshold = 120.0; // 120
CircleF[] circles = CvInvoke.HoughCircles(uimage, HoughType.Gradient, 2.0, 20.0, cannyThreshold, circleAccumulatorThreshold, 5);
watch.Stop();
msgBuilder.Append(String.Format("Hough circles - {0} ms; ", watch.ElapsedMilliseconds));
#endregion
#region Canny and edge detection
watch.Reset(); watch.Start();
double cannyThresholdLinking = 120.0; // 120
UMat cannyEdges = new UMat();
CvInvoke.Canny(uimage, cannyEdges, cannyThreshold, cannyThresholdLinking);
LineSegment2D[] lines = CvInvoke.HoughLinesP(
cannyEdges,
1, //Distance resolution in pixel-related units - 1
Math.PI / 45.0, //Angle resolution measured in radians.
0, //threshold - 20
0, //min Line width - 30
10); //gap between lines - 10
watch.Stop();
msgBuilder.Append(String.Format("Canny & Hough lines - {0} ms; ", watch.ElapsedMilliseconds));
#endregion
#region Find triangles and rectangles
watch.Reset(); watch.Start();
List <Triangle2DF> triangleList = new List <Triangle2DF>();
List <RotatedRect> boxList = new List <RotatedRect>(); //a box is a rotated rectangle
using (Emgu.CV.Util.VectorOfVectorOfPoint contours = new Emgu.CV.Util.VectorOfVectorOfPoint())
{
CvInvoke.FindContours(cannyEdges, contours, null, RetrType.List, ChainApproxMethod.ChainApproxSimple);
int count = contours.Size;
for (int i = 0; i < count; i++)
{
using (Emgu.CV.Util.VectorOfPoint contour = contours[i])
using (Emgu.CV.Util.VectorOfPoint approxContour = new Emgu.CV.Util.VectorOfPoint())
{
CvInvoke.ApproxPolyDP(contour, approxContour, CvInvoke.ArcLength(contour, true) * 0.05, true);
if (CvInvoke.ContourArea(approxContour, false) > 250) //only consider contours with area greater than 250
{
if (approxContour.Size == 3) //The contour has 3 vertices, it is a triangle
{
Point[] pts = approxContour.ToArray();
triangleList.Add(new Triangle2DF(
pts[0],
pts[1],
pts[2]
));
}
else if (approxContour.Size == 4) //The contour has 4 vertices.
{
#region determine if all the angles in the contour are within [80, 100] degree
bool isRectangle = true;
Point[] pts = approxContour.ToArray();
LineSegment2D[] edges = PointCollection.PolyLine(pts, true);
for (int j = 0; j < edges.Length; j++)
{
double angle = Math.Abs(
edges[(j + 1) % edges.Length].GetExteriorAngleDegree(edges[j]));
if (angle < 80 || angle > 100)
{
isRectangle = false;
break;
}
}
#endregion
if (isRectangle)
{
boxList.Add(CvInvoke.MinAreaRect(approxContour));
}
}
}
}
}
}
watch.Stop();
msgBuilder.Append(String.Format("Triangles & Rectangles - {0} ms; ", watch.ElapsedMilliseconds));
#endregion
//originalImageBox.Image = img.ToBitmap();
this.Text = msgBuilder.ToString();
#region draw triangles and rectangles
Image <Bgr, Byte> triangleRectangleImage = img.CopyBlank();
foreach (Triangle2DF triangle in triangleList)
{
triangleRectangleImage.Draw(triangle, new Bgr(Color.DarkBlue), 2);
}
foreach (RotatedRect box in boxList)
{
triangleRectangleImage.Draw(box, new Bgr(Color.DarkOrange), 2);
}
triangleRectangleImageBox1 = triangleRectangleImage.ToBitmap();
#endregion
#region draw circles
Image <Bgr, Byte> circleImage = img.CopyBlank();
foreach (CircleF circle in circles)
{
circleImage.Draw(circle, new Bgr(Color.Brown), 2);
}
circleImageBox1 = circleImage.ToBitmap();
#endregion
#region draw lines
Image <Bgr, Byte> lineImage = img.CopyBlank();
foreach (LineSegment2D line in lines)
{
lineImage.Draw(line, new Bgr(Color.Green), 2);
}
lineImageBox1 = lineImage.ToBitmap();
#endregion
cv_image = lineImageBox1;
pictureBox2.Image = lineImageBox1;
}
