private static void DrawMask(IInputOutputArray image, Mat mask, Rectangle rect, MCvScalar color)
{
using (Mat maskLarge = new Mat())
using (Mat maskLargeInv = new Mat())
using (InputArray iaImage = image.GetInputArray())
using (Mat matImage = iaImage.GetMat())
using (Mat subRegion = new Mat(matImage, rect))
using (Mat largeColor = new Mat(
subRegion.Size,
Emgu.CV.CvEnum.DepthType.Cv8U,
3))
{
CvInvoke.Resize(mask, maskLarge, rect.Size);
//give the mask at least 30% transparency
using (ScalarArray sa = new ScalarArray(0.7))
CvInvoke.Min(sa, maskLarge, maskLarge);
//Create the inverse mask for the original image
using (ScalarArray sa = new ScalarArray(1.0))
CvInvoke.Subtract(sa, maskLarge, maskLargeInv);
//The mask color
largeColor.SetTo(color);
if (subRegion.NumberOfChannels == 4)
{
using (Mat bgrSubRegion = new Mat())
{
CvInvoke.CvtColor(subRegion, bgrSubRegion,
ColorConversion.Bgra2Bgr);
CvInvoke.BlendLinear(largeColor, bgrSubRegion, maskLarge,
maskLargeInv, bgrSubRegion);
CvInvoke.CvtColor(bgrSubRegion, subRegion,
ColorConversion.Bgr2Bgra);
}
}
else
{
CvInvoke.BlendLinear(largeColor, subRegion, maskLarge, maskLargeInv,
subRegion);
}
}
}
