public static Bitmap ApplySodel(Bitmap srcImage)
{
var xkernel = xSobel;
var ykernel = ySobel;
ImageUtils image = new ImageUtils();
var buffer = image.BitmapToBytes(srcImage);
var width = image.Width;
var height = image.Height;
var bytes = image.Bytes;
var result = new byte[bytes];
directions = new double[bytes / 4];
resultBuf = new byte[bytes / 4];
xGradients = new double[bytes / 4];
yGradients = new double[bytes / 4];
var rgb = 0.0;
for (int i = 0; i < buffer.Length; i += 4)
{
rgb = buffer[i] * .3f;
rgb += buffer[i + 1] * .6f;
rgb += buffer[i + 2] * .1f;
buffer[i] = (byte)rgb;
buffer[i + 1] = buffer[i];
buffer[i + 2] = buffer[i];
buffer[i + 3] = 255;
}
var x = 0.0;
var y = 0.0;
var results = 0.0;
var filterOffset = 1;
var calcOffset = 0;
var byteOffset = 0;
for (var offsetY = filterOffset; offsetY < height - filterOffset; ++offsetY)
{
for (var offsetX = filterOffset; offsetX < width - filterOffset; ++offsetX)
{
x = y = 0;
results = 0.0;
byteOffset = offsetY * 4 * width + offsetX * 4;
for (var filterY = -filterOffset; filterY <= filterOffset; filterY++)
{
for (var filterX = -filterOffset; filterX <= filterOffset; filterX++)
{
calcOffset = byteOffset + filterX * 4 + filterY * 4 * width;
x += (double)(buffer[calcOffset]) * xkernel[filterY + filterOffset, filterX + filterOffset];
y += (double)(buffer[calcOffset]) * ykernel[filterY + filterOffset, filterX + filterOffset];
}
}
xGradients[byteOffset / 4] = x;
yGradients[byteOffset / 4] = y;
results += Math.Sqrt((x * x) + (y * y));
if (results > 255)
{
results = 255;
}
else if (results < 0)
{
results = 0;
}
if (x != 0)
{
var dirNotNorm = 57.29 * 1.0 / Math.Tan(y / x);
if (Math.Tan(y / x) == 0)
{
directions[byteOffset / 4] = 0;
}
else
{
directions[byteOffset / 4] = NormalizeDirection(dirNotNorm);
}
}
else
{
directions[byteOffset / 4] = 0;
}
resultBuf[byteOffset / 4] = (byte)results;
result[byteOffset] = (byte)(results);
result[byteOffset + 1] = (byte)(results);
result[byteOffset + 2] = (byte)(results);
result[byteOffset + 3] = 255;
}
}
return(image.BytesToBitmap(result));
}