/// <summary>
/// Shrinks the <paramref name="image"/> by half its size and returns the new image as result.
/// </summary>
internal static BinaryImage ShrinkByHalf(BinaryImage image)
{
var downSizedImage = new BinaryImage(image.Size.Width / 2, image.Size.Height / 2);
var matrixSize = new Size(2, 2);
Parallel.For(
0,
downSizedImage.Size.Height,
downSizedM =>
{
int originalM = downSizedM * 2;
for (int downSizedN = 0; downSizedN < downSizedImage.Size.Width; downSizedN++)
{
int originalN = downSizedN * 2;
var positionInImage = new MatrixPosition(originalM, originalN);
var neighbourMatrixFromPosition =
image.GetNeighborMatrixFromPosition(positionInImage, matrixSize);
float averageValue = neighbourMatrixFromPosition.GetAverageValue();
downSizedImage[downSizedM, downSizedN] = averageValue >= 0.75f
? BinaryImage.Black
: BinaryImage.White;
}
});
return(downSizedImage);
}
public void GetsNeighbourMatrixFromPosition(
BinaryImage binaryImage,
MatrixPosition positionInImage,
Size sizeOfNeighbourMatrix,
BinaryMatrix expectedResult)
{
var result = binaryImage.GetNeighborMatrixFromPosition(positionInImage, sizeOfNeighbourMatrix);
result.Should().Be(expectedResult);
}
