// TODO: Optional<Mat>
public HistChessboardModel Do(IVideo video)
{
HistChessboardModel model = null;
Mat frame;
Mat gray = new Mat();
Mat thresh = new Mat();
var corners = new Point2f[4];
var patternSize = new Size(7, 3);
var threshWin = new Window("Adaptive Threshold");
// TODO: each iteration, try different block sizes for the adaptive threshold (height / 4, height / 2, etc)
do
{
frame = video.GetNextFrame();
if (frame != null && frame.Width + frame.Height > 0)
{
Cv2.CvtColor(frame, gray, ColorConversionCodes.BGR2GRAY);
//Cv2.MedianBlur(gray, gray, 5); // Disallows chessboard to be found, because of how it opens/closes corners
Cv2.AdaptiveThreshold(gray, thresh,
maxValue: 255.0,
adaptiveMethod: AdaptiveThresholdTypes.GaussianC,
thresholdType: ThresholdTypes.Binary,
blockSize: (gray.Height / 4) | 1,
c: 0.0);
threshWin.ShowImage(thresh);
var found = Cv2.FindChessboardCorners(thresh, patternSize, out corners,
ChessboardFlags.None); //, ChessboardFlags.AdaptiveThresh | ChessboardFlags.NormalizeImage);
//frame.CopyTo(output);
//Cv2.DrawChessboardCorners(output, patternSize, corners, found);
//if (!found) Console.Out.WriteLine("Chessboard not found :( ");
if (found)
{
var boardPoints = new Point2d[21];
Point2d[] foundPoints = OCVUtil.Point2fTo2d(corners);
for (int c = 0; c < 7; c++)
{
for (int r = 0; r < 3; r++)
{
boardPoints[r * 7 + c] = new Point2d((c + 1.0), (r + 3.0));
}
}
var boardToImageTransform = Cv2.FindHomography(boardPoints, foundPoints);
var imageToBoardTransform =
boardToImageTransform.Inv(); //Cv2.FindHomography(foundPoints, boardPoints);
model = new HistChessboardModel(boardToImageTransform, imageToBoardTransform, frame);
}
}
} while (frame != null && model == null);
return(model);
}
Mat DrawSquaresMask(Mat frame)
{
var result = new Mat(frame.Size(), MatType.CV_8U, Scalar.Black);
for (int col = 0; col < 8; col++)
{
for (int row = 0; row < 8; row++)
{
var squarePoints = OCVUtil.ToPoints(GetSquarePoints(row, col, SquareMaskScale));
Cv2.FillConvexPoly(result, squarePoints, Scalar.White);
}
}
return(result);
}
Mat DrawBackgroundModel(Mat frame)
{
var result = new Mat(frame.Size(), frame.Type());
for (int col = 0; col < 8; col++)
{
for (int row = 0; row < 8; row++)
{
var color = IsWhiteSquare(row, col) ? WhiteSquareColor : BlackSquareColor;
var squarePoints = OCVUtil.ToPoints(GetSquarePoints(row, col));
Cv2.FillConvexPoly(result, squarePoints, color);
}
}
return(result);
}
public static void DrawSquareMask(int row, int col, Mat dest, Mat boardToImageTransform, double scale = 1.0)
{
var points = OCVUtil.ToPoints(GetSquarePoints(row, col, boardToImageTransform, scale));
Cv2.FillConvexPoly(dest, points, Scalar.White);
}