public static PNM ApplyCannyDetector(this PNM image)
{
PNM workImage = image.ApplyPointProcessing(Color.ToGrayscale)
.ApplyConvolutionMatrix(new float[] { 0, 0.01F, 0.02F, 0.01F, 0,
0.01F, 0.06F, 0.1F, 0.06F, 0.01F,
0.02F, 0.1F, 0.16F, 0.1F, 0.02F,
0.01F, 0.06F, 0.1F, 0.06F, 0.01F,
0, 0.01F, 0.02F, 0.01F, 0 }, 1, 0);
Filter.Pad(workImage, 1);
float[] xraster = Filter.ApplyConvolutionUnbound(workImage, SobelX, 3).Item1;
float[] yraster = Filter.ApplyConvolutionUnbound(workImage, SobelY, 3).Item1;
var vectorField = xraster.Zip(yraster, (x, y) => Tuple.Create(Module(x, y), GetOrientation(x, y))).ToArray();
byte[] suppressed = NonMaximumSuppression(vectorField, image.Width, image.Height);
return(ApplyHysteresis(suppressed, image.Width, image.Height, 0.05, 0.2));
}
