OpenCVSharp 2: FloodFill is broken and corrupts output mask

Question

Using latest v2 of OpenCVSharp (2.4.10.201...), which I installed in my project with the NuGet manager.

It seems the floodfill function has a memory-corruption issue. I am applying it to the following image:

and here is the result:

while the mask produced follows the same corruption pattern:

The code I use is:

filledArea = new CvMat( hue.Rows + 2, hue.Cols + 2, MatrixType.U8C1 );
Cv.FloodFill( hue, hintPos, new CvScalar(255,255,255), low, upp, out filledAreaData,
    FloodFillFlag.Link8 | FloodFillFlag.FixedRange, filledArea );

where hue is the input image

hintPos is CvPoint(10,400)

low = upp = CvScalar(10,10,10,10)

Note: the "corruption pattern" is random and changes every time.

Answer 1

It was a problem with not initializing the mask with zero values. It looks like this:

filledArea = new CvMat( hue.Rows + 2, hue.Cols + 2, MatrixType.U8C1 );

DOESN'T initialize the reserved memory to ANY value, so you get "corrupted" pixels.

filledArea = new CvMat( hue.Rows + 2, hue.Cols + 2, MatrixType.U8C1, new CvScalar(0,0,0,0) );

DOES create a mask with 0 pixels.

My wrong, I thought it wasn't possible in C# to grab new memory without first initializing it to some value, as is the case with Array[] and List...