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

        public bool IsConvexPolygon( List<IntPoint> edgePoints, out List<IntPoint> corners )
        {
            corners = GetShapeCorners( edgePoints );
            return CheckIfPointsFitShape( edgePoints, corners );
        }

        public static IEnumerable<MagicCard> DetectCardArt(Bitmap cameraBitmap)
        {
            var ret = new List<MagicCard>();

            var filteredBitmap = Grayscale.CommonAlgorithms.BT709.Apply(cameraBitmap);

            // edge filter
            var edgeFilter = new SobelEdgeDetector();
            edgeFilter.ApplyInPlace(filteredBitmap);

            // Threshhold filter
            var threshholdFilter = new Threshold(190);
            threshholdFilter.ApplyInPlace(filteredBitmap);

            var bitmapData = filteredBitmap.LockBits(
                new Rectangle(0, 0, filteredBitmap.Width, filteredBitmap.Height),
                ImageLockMode.ReadWrite, filteredBitmap.PixelFormat);

            var blobCounter = new BlobCounter();

            blobCounter.FilterBlobs = true;
            blobCounter.MinHeight = 125;
            blobCounter.MinWidth = 125;

            blobCounter.ProcessImage(bitmapData);
            var blobs = blobCounter.GetObjectsInformation();
            filteredBitmap.UnlockBits(bitmapData);

            var shapeChecker = new SimpleShapeChecker();
            var bm = new Bitmap(filteredBitmap.Width, filteredBitmap.Height, PixelFormat.Format24bppRgb);

            var cardPositions = new List<IntPoint>();
            foreach (var blob in blobs)
            {
                var edgePoints = blobCounter.GetBlobsEdgePoints(blob);

                List<IntPoint> corners;

                // only operate on 4 sided polygons
                if (shapeChecker.IsConvexPolygon(edgePoints, out corners))
                {
                    var subtype = shapeChecker.CheckPolygonSubType(corners);

                    if (corners.Count() != 4)
                        continue;

                    if (subtype != PolygonSubType.Parallelogram && subtype != PolygonSubType.Rectangle)
                        continue;

                    // if the image is sideways, rotate it so it'll match the DB card art
                    corners = Utilities.RotateCorners(corners).ToList();

                    if (Utilities.GetArea(corners) < 20000)
                        continue;

                    ret.Add( new MagicCard(cameraBitmap, corners));
                }
            }

            return ret;
        }