private static void Convolve(FloatBufferImage src, FloatBufferImage dst, float[] mask, int y0, int y1)
{
for (var y = y0; y < y1; y++)
{
for (var x = 0; x < src.W; x++)
{
var sum = src.Get(x, y);
sum.R *= mask[0];
sum.G *= mask[0];
sum.B *= mask[0];
for (var i = 1; i < mask.Length; i++)
{
var cl = src.Get(Math.Max(x - i, 0), y);
var cr = src.Get(Math.Min(x + i, src.W - 1), y);
sum.R += mask[i] * (cl.R + cr.R);
sum.G += mask[i] * (cl.G + cr.G);
sum.B += mask[i] * (cl.B + cr.B);
}
dst.Set(sum, y, x);
}
}
}
public static BImage Smooth(BImage img, float sigma, bool useMultiTreading = true)
{
if (Math.Abs(sigma) < 0.01f)
{
return(img);
}
var mask = Mask(sigma);
var src = new FloatBufferImage(img);
var tmp = ConvolveMulti(src, mask, useMultiTreading ? Environment.ProcessorCount : 1);
var res = ConvolveMulti(tmp, mask, useMultiTreading ? Environment.ProcessorCount : 1);
return(res.ToBImage());
}
private static FloatBufferImage ConvolveMulti(FloatBufferImage src, float[] mask, int parallel)
{
// transparent
var result = new FloatBufferImage(src.H, src.W);
var srcStrips = GenerateStrips(src.H, parallel);
var tasks = new Task[srcStrips.Count - 1];
for (var i = 0; i < tasks.Length; i++)
{
var index = i;
tasks[i] = new Task(() => {
Convolve(src, result, mask, srcStrips[index], srcStrips[index + 1]);
});
tasks[i].Start();
}
foreach (var t in tasks)
{
t.Wait();
}
return(result);
}
