added simple fft

math/dsp/Convolution2D.h

@@ -0,0 +1,74 @@
+#ifndef CONVOLUTION2D_H
+#define CONVOLUTION2D_H
+
+#ifndef __USE_SQUARE_BRACKETS_FOR_ELEMENT_ACCESS_OPERATOR
+#define __USE_SQUARE_BRACKETS_FOR_ELEMENT_ACCESS_OPERATOR
+#endif
+
+#include "../../math/boxkde/Image2D.h"
+#include "../../lib/simple_fft/fft.h"
+
+
+namespace DSP {
+
+template <typename Scalar> class Convolution2D {
+
+public:
+
+    static inline Image2D<Scalar> convolve(Image2D<Scalar> signal, Image2D<Scalar> kernel){
+
+        RealArray2D signalReal;
+        ComplexArray2D signalSpectrum;
+
+        RealArray2D kernelReal;
+        ComplexArray2D kernelSpectrum;
+
+
+        signal.data().data
+
+
+        //convert image2d single vector to 2d vector, just use pointers
+        int signal_x = signal.width;
+        int signal_y = signal.height;
+        int kernel_x = kernel.width;
+        int kernel_y = kernel.height;
+
+        //check if power of 2, if not fill with zeros
+        while(!isPowerOfTwo(signal_x)){
+
+        }
+
+        if(!isPowerOfTwo(kernel.size)){
+
+        }
+
+
+        //calculate FFT for both
+
+        simple_fft::FFT();
+
+        //multiplay the results pointwise
+
+        //IFFT
+        simple_fft::IFFT();
+
+        //profit?
+    }
+
+private:
+
+    typedef std::vector<std::vector<complex_type> > ComplexArray2D;
+    typedef std::vector<std::vector<real_type> > RealArray2D;
+
+
+
+    bool isPowerOfTwo (unsigned int x)
+    {
+      return ((x != 0) && !(x & (x - 1)));
+    }
+
+};
+}
+
+
+#endif // CONVOLUTION_H