|
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;
}
public static void Rectangle(WriteableBitmap bitmap, DrawingContext dc)
{
// locating objects
BlobCounter blobCounter = new BlobCounter();
blobCounter.FilterBlobs = true;
blobCounter.MaxHeight = 375;
blobCounter.MaxWidth = 375;
System.Drawing.Bitmap image;
using (var stream = new MemoryStream())
{
var encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
encoder.Save(stream);
image = new System.Drawing.Bitmap(stream);
}
blobCounter.ProcessImage(image);
Blob[] blobs = blobCounter.GetObjectsInformation();
// check for rectangles
SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
foreach (var blob in blobs)
{
List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blob);
List<IntPoint> cornerPoints;
// use the shape checker to extract the corner points
if (shapeChecker.IsQuadrilateral(edgePoints, out cornerPoints))
{
// only do things if the corners form a rectangle
if (shapeChecker.CheckPolygonSubType(cornerPoints) == PolygonSubType.Rectangle)
{
// here i use the graphics class to draw an overlay, but you
// could also just use the cornerPoints list to calculate your
// x, y, width, height values.
List<AForge.Point> Points = new List<AForge.Point>();
foreach (var point in cornerPoints)
{
Points.Add(new AForge.Point(point.X, point.Y));
}
var path = new PathFigure(new System.Windows.Point(Points.First().X, Points.First().Y), Points.Select(row => new System.Windows.Media.LineSegment(new System.Windows.Point(row.X, row.Y), false)), true);
dc.DrawGeometry(Brushes.Red, null, new PathGeometry(new PathFigure[] { path }));
}
}
}
}
