Please, refer to this article.
I have implemented the section 4.1 (Pre-processing).
The preprocessing step aims to enhance image features along a set of chosen directions. First, image is grey-scaled and filtered with a sharpening filter (we subtract from the image its local-mean filtered version), thus eliminating the DC component.
We selected 12 not overlapping filters, to analyze 12 different directions, rotated with respect to 15° each other.
Since, the given formula in the article is incorrect, I have tried two sets of different formulas.
The first set of formula,
The second set of formula,
The expected output should be,
Neither of them are giving proper results.
Can anyone suggest me any modification?
Most relevalt part of the source code is here:
public List<Bitmap> Apply(Bitmap bitmap)
{
Kernels = new List<KassWitkinKernel>();
double degrees = FilterAngle;
KassWitkinKernel kernel;
for (int i = 0; i < NoOfFilters; i++)
{
kernel = new KassWitkinKernel();
kernel.Width = KernelDimension;
kernel.Height = KernelDimension;
kernel.CenterX = (kernel.Width) / 2;
kernel.CenterY = (kernel.Height) / 2;
kernel.Du = 2;
kernel.Dv = 2;
kernel.ThetaInRadian = Tools.DegreeToRadian(degrees);
kernel.Compute();
//SleuthEye
kernel.Pad(kernel.Width, kernel.Height, WidthWithPadding, HeightWithPadding);
Kernels.Add(kernel);
degrees += degrees;
}
List<Bitmap> list = new List<Bitmap>();
Bitmap image = (Bitmap)bitmap.Clone();
//PictureBoxForm f = new PictureBoxForm(image);
//f.ShowDialog();
Complex[,] cImagePadded = ImageDataConverter.ToComplex(image);
Complex[,] fftImage = FourierTransform.ForwardFFT(cImagePadded);
foreach (KassWitkinKernel k in Kernels)
{
Complex[,] cKernelPadded = k.ToComplexPadded();
Complex[,] convolved = Convolution.ConvolveInFrequencyDomain(fftImage, cKernelPadded);
Bitmap temp = ImageDataConverter.ToBitmap(convolved);
list.Add(temp);
}
return list;
}