public Bitmap FixPerspective()
{
double maxWidth = 0;
double maxHeight = 0;
OpenCV.Core.Point pTopLeft, pBottomLeft, pBottomRight, pTopRight;
GetImageMaxSize(out maxWidth, out maxHeight, out pTopLeft, out pBottomLeft, out pBottomRight, out pTopRight);
if (maxWidth <= 0 || maxHeight <= 0)
{
return(null);
}
CreateSrcDstArrays(maxWidth, maxHeight, pTopLeft, pBottomLeft, pBottomRight, pTopRight, out MatOfPoint2f src, out MatOfPoint2f dst);
Mat undistortedMat = new Mat(new OpenCV.Core.Size(maxWidth, maxHeight), OpenCV.Core.CvType.Cv8uc4);
Mat ptMat = Imgproc.GetPerspectiveTransform(src, dst);
Imgproc.WarpPerspective(originalMat, undistortedMat, ptMat, new OpenCV.Core.Size(maxWidth, maxHeight));
Bitmap undistortedBitmap = Bitmap.CreateBitmap((int)maxWidth, (int)maxHeight, Bitmap.Config.Argb8888);
OpenCV.Android.Utils.MatToBitmap(undistortedMat, undistortedBitmap);
return(undistortedBitmap);
}
/// <summary>
/// Creates the transformation matrix (in both directions) to wrap the zone in front of the car.
/// </summary>
/// <param name="src"> source image </param>
/// <param name="transform"> transformation matrix </param>
/// <param name="inv_transform"> inverse transformation matrix </param>
/// <param name="warp"> wrapped zone of interest </param>
public void GetBirdEye(Mat bin, Mat src, float marginX, float marginY, out Mat transform, out Mat inv_transform, out Mat warp)
{
// Create perspective in front of the car
Core.Point[] sourcePeaks =
{
new Core.Point(bin.Width() * marginX, bin.Height() * marginY),
new Core.Point(bin.Width() * (1 - marginX), bin.Height() * marginY),
new Core.Point(bin.Width(), bin.Height()),
new Core.Point(0, bin.Height()),
new Core.Point(bin.Width() * marginX, bin.Height() * marginY)
};
MatOfPoint2f sourceMat = new MatOfPoint2f(
sourcePeaks[0],
sourcePeaks[1],
sourcePeaks[2],
sourcePeaks[3]
);
Core.Point[] targetPeaks =
{
new Core.Point(0, 0),
new Core.Point(bin.Width(), 0),
new Core.Point(bin.Width(), bin.Height()),
new Core.Point(0, bin.Height()),
new Core.Point(0, 0)
};
// Generate transformation matrix in both directions
MatOfPoint2f targetMat = new MatOfPoint2f(
targetPeaks[0],
targetPeaks[1],
targetPeaks[2],
targetPeaks[3]
);
transform = Imgproc.GetPerspectiveTransform(sourceMat, targetMat);
inv_transform = Imgproc.GetPerspectiveTransform(targetMat, sourceMat);
warp = new Mat(bin.Size(), bin.Type());
Imgproc.WarpPerspective(bin, warp, transform, bin.Size(), Imgproc.InterLinear);
// Draw
for (int iPeak = 0; iPeak < sourcePeaks.GetLength(0) - 1; iPeak++)
{
Imgproc.Line(src, sourcePeaks[iPeak], sourcePeaks[iPeak + 1], new Scalar(0, 255, 0), 3);
}
}