public EdgeCutter(bool replaceAll)
{
Console.WriteLine("replaceAll: " + replaceAll);
_replaceAll = replaceAll;
_backgroundColor = Color.FromArgb(255, 6, 208, 0).ToDoubleColor();
//_backgroundColor = Color.FromArgb(255, 0, 166, 255).ToDoubleColor();
}
public Bitmap Cut(string path)
{
Bitmap img = null;
using (var image = new Bitmap(path))
{
img = new Bitmap(image);
image.Dispose();
var diffMax = 0.0;
Func <DoubleColor, Double> getColorDiff = (col) => col.B - col.R;
// get greedDifMax
for (int i = 0; i < img.Width; i++)
{
for (int j = 0; j < img.Height; j++)
{
var col = img.GetPixel(i, j).ToDoubleColor();
var diff = getColorDiff(col);
if (diff > diffMax)
{
diffMax = diff;
}
}
}
// backgroundColor to Alpha
for (int i = 0; i < img.Width; i++)
{
for (int j = 0; j < img.Height; j++)
{
var col = img.GetPixel(i, j).ToDoubleColor();
// How much more green is there than blue in this specific pixel
var diff = getColorDiff(col);
// if there IS more green than blue in this pixel, it is a greenish pixel and
// needs to be corrected.
if (diff > 0)
{
// correcting greenish pixel in here.
// - - calculate the alpha of the new pixel - -
// - We already know that it will be a white (1,1,1) pixel.
// - We also know that pixels that are (6, 208, 0) will need to get an
// alpha of 1.
var degreeInDifference = 1 / diffMax * diff;
var alpha = degreeInDifference - 1;
// since the algorithm which added the green edge to the
// text depicted in the image data wasn't doing traditional alpha blending
// the alpha needs to be distorted a little to get as close as possible
// to the ideal result.
alpha *= alpha;
var newCol = new DoubleColor(Clamp01(alpha), 1, 1, 1).ToByteColor();
img.SetPixel(i, j, newCol);
}
}
}
}
return(img);
}
