public override IObservable <CameraCalibration> Process(IObservable <KeyPointCollection[]> source)
{
return(Observable.Defer(() =>
{
var guess = false;
var imageSize = new Size();
var patternSize = new Size();
var calibration = new CameraCalibration();
var cameraMatrix = new Mat(3, 3, Depth.F32, 1);
var distortion = new Mat(1, 5, Depth.F32, 1);
Point3f[] chessboardCorners = null;
return source.Select(input =>
{
if (patternSize != PatternSize)
{
patternSize = PatternSize;
chessboardCorners = new Point3f[patternSize.Width * patternSize.Height];
for (int i = 0; i < chessboardCorners.Length; i++)
{
chessboardCorners[i].X = i % patternSize.Width;
chessboardCorners[i].Y = i / patternSize.Width;
chessboardCorners[i].Z = 0;
}
}
var flags = CalibrationFlags;
if (input.Length == 0)
{
if ((flags & CameraCalibrationFlags.UseIntrinsicGuess) == 0)
{
calibration = new CameraCalibration();
}
return calibration;
}
var totalPoints = 0;
var pointCounts = new int[input.Length];
for (int i = 0; i < pointCounts.Length; i++)
{
var image = input[i].Image;
if (input[i].Count == 0)
{
continue;
}
if (imageSize.Width == 0)
{
imageSize = image.Size;
}
else if (imageSize != image.Size)
{
throw new InvalidOperationException("Chessboard calibration features must come from same-sized images.");
}
pointCounts[i] = input[i].Count;
totalPoints += pointCounts[i];
}
var objectPoints = new Point3f[totalPoints];
var imagePoints = new Point2f[totalPoints];
totalPoints = 0;
for (int i = 0; i < input.Length; i++)
{
input[i].CopyTo(imagePoints, totalPoints);
Array.Copy(chessboardCorners, 0, objectPoints, totalPoints, input[i].Count);
totalPoints += input[i].Count;
}
if (!guess)
{
flags &= ~CameraCalibrationFlags.UseIntrinsicGuess;
}
using (var objectPts = Mat.CreateMatHeader(objectPoints, objectPoints.Length, 3, Depth.F32, 1))
using (var imagePts = Mat.CreateMatHeader(imagePoints, imagePoints.Length, 2, Depth.F32, 1))
using (var pointCts = Mat.CreateMatHeader(pointCounts, pointCounts.Length, 1, Depth.S32, 1))
{
calibration.ReprojectionError = CV.CalibrateCamera2(
objectPts, imagePts, pointCts, imageSize,
cameraMatrix, distortion, null, null, flags);
Intrinsics.FromCameraMatrix(cameraMatrix, distortion, imageSize, out calibration.Intrinsics);
}
guess = true;
return calibration;
});
}));
}