AForge.Math.Geometry.SimpleShapeChecker.IsQuadrilateral C# (CSharp) Method

IsQuadrilateral() public method

Check if the specified set of points form a quadrilateral shape.
public IsQuadrilateral ( List edgePoints ) : bool
edgePoints List Shape's points to check.
return bool
        public bool IsQuadrilateral( List<IntPoint> edgePoints )
        {
            List<IntPoint> corners;
            return IsQuadrilateral( edgePoints, out corners );
        }

Same methods

SimpleShapeChecker::IsQuadrilateral ( List edgePoints, List &corners ) : bool

Usage Example

Example #1
1
        public double[] detectionGlyph(bool CalculTailleTerrain)
        {
            bool Trouve = false;
            double[] ratio = new double[2] { 0, 0 };
            SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
            BlobCounter blobCounter = new BlobCounter();

            blobCounter.MinHeight = 23;
            blobCounter.MinWidth = 23;
            blobCounter.FilterBlobs = true;
            blobCounter.ObjectsOrder = ObjectsOrder.Size;

            // 4 - find all stand alone blobs
            blobCounter.ProcessImage(imgContour);
            Blob[] blobs = blobCounter.GetObjectsInformation();

            // 5 - check each blob
            for (int i = 0, n = blobs.Length; i < n; i++)
            {
                List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);
                List<IntPoint> corners = null;

                // Test de la forme selectionnée
                if (shapeChecker.IsQuadrilateral(edgePoints, out corners))
                {
                    // Détection des points de coutour
                    List<IntPoint> leftEdgePoints, rightEdgePoints, topEdgePoints, bottomEdgePoints;

                    Line Horizontale = Line.FromPoints(new IntPoint(0,0),new IntPoint(10,0));
                    blobCounter.GetBlobsLeftAndRightEdges(blobs[i], out leftEdgePoints, out rightEdgePoints);
                    blobCounter.GetBlobsTopAndBottomEdges(blobs[i], out topEdgePoints, out bottomEdgePoints);

                    // calculate average difference between pixel values from outside of the
                    // shape and from inside
                    float diff = CalculateAverageEdgesBrightnessDifference(leftEdgePoints, rightEdgePoints, imgNB);
                    // check average difference, which tells how much outside is lighter than
                    // inside on the average
                    if (diff > 20)
                    {
                        // Transformation de l'image reçu en un carré pour la reconnaissance
                        QuadrilateralTransformation quadrilateralTransformation = new QuadrilateralTransformation(corners, 60, 60);
                        UnmanagedImage glyphImage = quadrilateralTransformation.Apply(imgNB);

                        // Filtre de contraste
                        OtsuThreshold otsuThresholdFilter = new OtsuThreshold();
                        otsuThresholdFilter.ApplyInPlace(glyphImage);
                        imgContour = glyphImage;
                        // Reconnaissance du Glyph
                        Glyph Gl = new Glyph(glyphImage, GlyphSize);

                        Gl.ReconnaissanceGlyph(corners, imgNB);

                        // Si le Glyph est valide
                        if (Gl.getIdentifiant() > 0)
                        {
                            if (AutAffichage[0])
                            {
                                // Coloration des contours des zones détectées
                                UnImgReel.SetPixels(leftEdgePoints, Color.Red);
                                UnImgReel.SetPixels(rightEdgePoints, Color.Red);
                                UnImgReel.SetPixels(topEdgePoints, Color.Red);
                                UnImgReel.SetPixels(bottomEdgePoints, Color.Red);
                            }

                            // Détection du milieu
                            Line line = Line.FromPoints(corners[0], corners[2]);
                            Line line2 = Line.FromPoints(corners[1], corners[3]);
                            IntPoint intersection = (IntPoint)line.GetIntersectionWith(line2);
                            if (AutAffichage[1])
                            {
                                dessinePoint(intersection, UnImgReel, 4, Color.Yellow);
                            }

                            // Calcul de la rotation
                            Line ComparasionAngle = Line.FromPoints(corners[0], corners[1]);
                            Double rotation = (int) ComparasionAngle.GetAngleBetweenLines(Horizontale);
                            rotation += 90 * Gl.getNbRotation();
                            Gl.rotation = 360 - rotation;
                            rotation *= (Math.PI / 180.0);

                            // Calcul d'un point en bout de pince
                            float Taille = corners[0].DistanceTo(corners[1]);

                            float taille = (Taille / BibliotequeGlyph.Biblioteque[Gl.getPosition()].taille) * BibliotequeGlyph.Biblioteque[Gl.getPosition()].DistancePince;
                            int x = -(int)(System.Math.Sin(rotation) * taille);
                            int y = -(int)(System.Math.Cos(rotation) * taille);
                            x += (int)intersection.X;
                            y += (int)intersection.Y;
                            Gl.Position = new int[2]{x,y};
                            if (AutAffichage[2])
                            {
                                dessinePoint(new IntPoint(x, y), UnImgReel, 4, Color.Cyan);
                            }
                            imgContour = Gl.getImage();
                            addGlyph(Gl);

                            if (CalculTailleTerrain == true && Trouve == false)
                            {
                                Trouve = true;
                                int tailleglyph = BibliotequeGlyph.Biblioteque[Gl.getPosition()].taille;

                                // Pythagore pour detection taille
                                Rectangle a = blobs[i].Rectangle;
                                double angle = - Gl.rotation + 180;
                                List<IntPoint> coins = new List<IntPoint>();
                                coins.Add(new IntPoint(100,100));
                                coins.Add(new IntPoint(100, 100 + tailleglyph));
                                coins.Add(new IntPoint(100 + tailleglyph , 100 + tailleglyph));
                                coins.Add(new IntPoint(100 + tailleglyph, 100));
                                IntPoint Centre = new IntPoint((coins[2].X + coins[0].X)/2, (coins[2].Y + coins[0].Y) / 2);
                                int radius = (int)(0.5 * Math.Sqrt(coins[0].DistanceTo(coins[1]) * coins[0].DistanceTo(coins[1]) + coins[1].DistanceTo(coins[2]) * coins[1].DistanceTo(coins[2])));
                                double alpha = Math.Atan2(coins[0].DistanceTo(coins[1]), coins[1].DistanceTo(coins[2])) * (180 / Math.PI);

                                double ang = 0;
                                for(i = 0; i < 4; i++)
                                {
                                    IntPoint tmp = coins[i];
                                    switch (i)
                                    {
                                        case 0:
                                            ang = alpha - 180 + angle;
                                            break;
                                        case 1:
                                            ang = + angle - alpha;
                                            break;
                                        case 2:
                                            ang = + angle + alpha;
                                            break;
                                        case 3:
                                            ang = - alpha + 180 + angle;
                                            break;
                                    }
                                    ang *= (Math.PI / 180);
                                    tmp.X = (int)(Centre.X + radius * Math.Cos(ang));
                                    tmp.Y = (int)(Centre.Y + radius * Math.Sin(ang));

                                    coins[i] = tmp;
                                }

                                Rectangle r = new Rectangle(min(coins[0].X, coins[1].X, coins[2].X, coins[3].X), min(coins[0].Y, coins[1].Y, coins[2].Y, coins[3].Y),
                                                            max(coins[0].X, coins[1].X, coins[2].X, coins[3].X) - min(coins[0].X, coins[1].X, coins[2].X, coins[3].X),
                                                            max(coins[0].Y, coins[1].Y, coins[2].Y, coins[3].Y) - min(coins[0].Y, coins[1].Y, coins[2].Y, coins[3].Y));
                                ratio[0] = ((double)r.Width / (double)a.Width) * 1.48;
                                ratio[1] = ((double)r.Height / (double)a.Height) * 1.48;

                            }
                        }
                    }
                }
            }
            if (Trouve == false || ratio[0] == 0 || ratio[0] == 1 || ratio[1] == 0 || ratio[1] == 1)
            {
                return null;
            }
            ratio[0] *= 0.7;
            ratio[1] *= 0.7;
            return ratio;
        }
All Usage Examples Of AForge.Math.Geometry.SimpleShapeChecker::IsQuadrilateral