public Matrix Apply(Matrix input)
{
var guassian = ImageFilters.Gaussian(0.6f, 5);
var r = new ImageData(input.Width, input.Height, PixelFormats.Gray8);
var blurred = ImageProcessing.Convolve(input, guassian);
r[0] = ImageProcessing.Scale(blurred, 0, 255);
r.Save <JpegBitmapEncoder>(@"C:\imageprocessing\blurred.jpg");
var gx = ImageProcessing.Convolve(input, new float[, ]
{
{ -1, 0, 1 },
{ -2, 0, 2 },
{ -1, 0, 1 }
});
r[0] = ImageProcessing.Scale(gx, 0, 255);
r.Save <JpegBitmapEncoder>(@"C:\imageprocessing\gx.jpg");
var gy = ImageProcessing.Convolve(input, new float[, ]
{
{ 1, 2, 1 },
{ 0, 0, 0 },
{ -1, -2, -1 }
});
r[0] = ImageProcessing.Scale(gy, 0, 255);
r.Save <JpegBitmapEncoder>(@"C:\imageprocessing\gy.jpg");
var gradient = Matrix.Sqrt(Matrix.Pow(gx, 2) + Matrix.Pow(gy, 2));
r[0] = ImageProcessing.Scale(gradient, 0, 255);
r.Save <JpegBitmapEncoder>(@"C:\imageprocessing\gradient.jpg");
var angle = new Matrix(input.Width, input.Height);
for (var x = 1; x < gradient.Width - 1; x++)
{
for (var y = 1; y < gradient.Height - 1; y++)
{
var orientation = (float)(Math.Atan2(gy[x, y], gx[x, y]) * 180f / Math.PI);
if (orientation < 0)
{
orientation += 180f;
}
angle[x, y] = orientation;
}
}
r[0] = ImageProcessing.Scale(angle, 0, 255);
r.Save <JpegBitmapEncoder>(@"C:\imageprocessing\angle.jpg");
var result = new Matrix(input.Width, input.Height);
for (var x = 1; x < gradient.Width - 1; x++)
{
for (var y = 1; y < gradient.Height - 1; y++)
{
var orientation = angle[x, y];
var val = gradient[x, y];
// N-S
if (orientation <= 22.5 || orientation >= 157.5)
{
if (gradient[x, y] > gradient[x, y - 1] &&
gradient[x, y] > gradient[x, y + 1])
{
result[x, y] = val;
}
}
// E-W
if (orientation >= 67.5 && orientation <= 112.5)
{
if (gradient[x, y] > gradient[x - 1, y] &&
gradient[x, y] > gradient[x + 1, y])
{
result[x, y] = val;
}
}
// NE-SW
if (orientation >= 22.5 && orientation <= 67.5)
{
if (gradient[x, y] > gradient[x + 1, y - 1] &&
gradient[x, y] > gradient[x - 1, y + 1])
{
result[x, y] = val;
}
}
// SE-NW
if (orientation <= 157.5 && orientation >= 112.5)
{
if (gradient[x, y] > gradient[x - 1, y - 1] &&
gradient[x, y] > gradient[x + 1, y + 1])
{
result[x, y] = val;
}
}
}
}
return(result);
}