private static void BuildOctave(Pyramid pyramid, int index, int layers, double sigma0, double k,
Mat image)
{
var list = new List<PyramidMat>(layers);
var dogList = new List<Mat>(layers);
var sigmaPrev = sigma0;
list.Add(new PyramidMat(image, index, 0, sigmaPrev, sigmaPrev * (1 << index)));
for (var i = 1; i < layers; i++)
{
var sigmaCurrent = sigmaPrev * k;
var prevImage = list[list.Count - 1].GetMat();
var currentImage = GaussBlur(prevImage, sigma0, sigmaCurrent);
list.Add(new PyramidMat(currentImage, index, i + 1, sigmaCurrent, sigmaCurrent * (1 << index)));
dogList.Add(Diff(currentImage, prevImage));
sigmaPrev = sigmaCurrent;
}
pyramid.octaves.Add(index, list);
pyramid.dog.Add(index, dogList);
}
public static Pyramid Build(Mat source, int layers, double sigma1, double sigma0)
{
if (sigma1 > sigma0)
throw new ArgumentException("sigma1 must be <= sigma0");
var image = GaussBlur(source, sigma1, sigma0);
var pyramid = new Pyramid(sigma0, Depth, layers);
var k = Math.Pow(2, 1D / layers);
for (var i = 0; i < Depth; i++)
{
BuildOctave(pyramid, i, layers + Overlap, sigma0, k, image);
var result = pyramid.octaves[i];
if (i != Depth - 1)
image = Downscale(result[layers].GetMat());
}
return pyramid;
}
