|
public CheckPolygonSubType ( List |
||
| corners | List |
Corners of the convex polygon to check. |
| return | PolygonSubType | |
public PolygonSubType CheckPolygonSubType( List<IntPoint> corners )
{
PolygonSubType subType = PolygonSubType.Unknown;
// get bounding rectangle of the points list
IntPoint minXY, maxXY;
PointsCloud.GetBoundingRectangle( corners, out minXY, out maxXY );
// get cloud's size
IntPoint cloudSize = maxXY - minXY;
float maxLengthDiff = lengthError * ( cloudSize.X + cloudSize.Y ) / 2;
if ( corners.Count == 3 )
{
// get angles of the triangle
float angle1 = GeometryTools.GetAngleBetweenVectors( corners[0], corners[1], corners[2] );
float angle2 = GeometryTools.GetAngleBetweenVectors( corners[1], corners[2], corners[0] );
float angle3 = GeometryTools.GetAngleBetweenVectors( corners[2], corners[0], corners[1] );
// check for equilateral triangle
if ( ( Math.Abs( angle1 - 60 ) <= angleError ) &&
( Math.Abs( angle2 - 60 ) <= angleError ) &&
( Math.Abs( angle3 - 60 ) <= angleError ) )
{
subType = PolygonSubType.EquilateralTriangle;
}
else
{
// check for isosceles triangle
if ( ( Math.Abs( angle1 - angle2 ) <= angleError ) ||
( Math.Abs( angle2 - angle3 ) <= angleError ) ||
( Math.Abs( angle3 - angle1 ) <= angleError ) )
{
subType = PolygonSubType.IsoscelesTriangle;
}
// check for rectangled triangle
if ( ( Math.Abs( angle1 - 90 ) <= angleError ) ||
( Math.Abs( angle2 - 90 ) <= angleError ) ||
( Math.Abs( angle3 - 90 ) <= angleError ) )
{
subType = ( subType == PolygonSubType.IsoscelesTriangle ) ?
PolygonSubType.RectangledIsoscelesTriangle : PolygonSubType.RectangledTriangle;
}
}
}
else if ( corners.Count == 4 )
{
// get angles between 2 pairs of opposite sides
float angleBetween1stPair = GeometryTools.GetAngleBetweenLines( corners[0], corners[1], corners[2], corners[3] );
float angleBetween2ndPair = GeometryTools.GetAngleBetweenLines( corners[1], corners[2], corners[3], corners[0] );
// check 1st pair for parallelism
if ( angleBetween1stPair <= angleError )
{
subType = PolygonSubType.Trapezoid;
// check 2nd pair for parallelism
if ( angleBetween2ndPair <= angleError )
{
subType = PolygonSubType.Parallelogram;
// check angle between adjacent sides
if ( Math.Abs( GeometryTools.GetAngleBetweenVectors( corners[1], corners[0], corners[2] ) - 90 ) <= angleError )
{
subType = PolygonSubType.Rectangle;
}
// get length of 2 adjacent sides
float side1Length = (float) corners[0].DistanceTo( corners[1] );
float side2Length = (float) corners[0].DistanceTo( corners[3] );
if ( Math.Abs( side1Length - side2Length ) <= maxLengthDiff )
{
subType = ( subType == PolygonSubType.Parallelogram ) ?
PolygonSubType.Rhombus : PolygonSubType.Square;
}
}
}
else
{
// check 2nd pair for parallelism - last chence to detect trapezoid
if ( angleBetween2ndPair <= angleError )
{
subType = PolygonSubType.Trapezoid;
}
}
}
return subType;
}
// Process image
private void ProcessImage(Bitmap bitmap)
{
// lock image
BitmapData bitmapData = bitmap.LockBits(
new Rectangle(0, 0, bitmap.Width, bitmap.Height),
ImageLockMode.ReadWrite, bitmap.PixelFormat);
// step 1 - turn background to black
ColorFiltering colorFilter = new ColorFiltering();
colorFilter.Red = new IntRange(0, 64);
colorFilter.Green = new IntRange(0, 64);
colorFilter.Blue = new IntRange(0, 64);
colorFilter.FillOutsideRange = false;
colorFilter.ApplyInPlace(bitmapData);
// step 2 - locating objects
BlobCounter blobCounter = new BlobCounter();
blobCounter.FilterBlobs = true;
blobCounter.MinHeight = 5;
blobCounter.MinWidth = 5;
blobCounter.ProcessImage(bitmapData);
Blob[] blobs = blobCounter.GetObjectsInformation();
bitmap.UnlockBits(bitmapData);
// step 3 - check objects' type and highlight
SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
Graphics g = Graphics.FromImage(bitmap);
Pen yellowPen = new Pen(Color.Yellow, 2); // circles
Pen redPen = new Pen(Color.Red, 2); // quadrilateral
Pen brownPen = new Pen(Color.Brown, 2); // quadrilateral with known sub-type
Pen greenPen = new Pen(Color.Green, 2); // known triangle
Pen bluePen = new Pen(Color.Blue, 2); // triangle
for (int i = 0, n = blobs.Length; i < n; i++)
{
List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);
Accord.Point center;
float radius;
// is circle ?
if (shapeChecker.IsCircle(edgePoints, out center, out radius))
{
g.DrawEllipse(yellowPen,
(float)(center.X - radius), (float)(center.Y - radius),
(float)(radius * 2), (float)(radius * 2));
}
else
{
List<IntPoint> corners;
// is triangle or quadrilateral
if (shapeChecker.IsConvexPolygon(edgePoints, out corners))
{
// get sub-type
PolygonSubType subType = shapeChecker.CheckPolygonSubType(corners);
Pen pen;
if (subType == PolygonSubType.Unknown)
{
pen = (corners.Count == 4) ? redPen : bluePen;
}
else
{
pen = (corners.Count == 4) ? brownPen : greenPen;
}
g.DrawPolygon(pen, ToPointsArray(corners));
}
}
}
yellowPen.Dispose();
redPen.Dispose();
greenPen.Dispose();
bluePen.Dispose();
brownPen.Dispose();
g.Dispose();
// put new image to clipboard
Clipboard.SetDataObject(bitmap);
// and to picture box
pictureBox.Image = bitmap;
UpdatePictureBoxPosition();
}