lecture/3. Signal Processing/code_signal_processing.jl

@@ -1,46 +0,0 @@
-using Images
-using PyPlot
-using FFTW
-
-N = 64
-x = shepp_logan(N)
-
-figure(1)
-clf()
-subplot(2,2,1)
-imshow(x)
-
-X = fft(x)
-subplot(2,2,2)
-imshow(abs.(X))
-
-Y = fftshift(X)
-subplot(2,2,3)
-imshow(abs.(Y))
-
-Y[1:div(N,4)+1,:] .= 0.0
-Y[3*div(N,4):end,:] .= 0.0
-Y[:,1:div(N,4)+1] .= 0.0
-Y[:,3*div(N,4):end] .= 0.0
-
-subplot(2,2,4)
-imshow(abs.(Y))
-
-
-figure(2)
-clf()
-imshow(abs.(ifft(ifftshift(Y))))
-
-
-
-function mydft(x)
-  N = length(x)
-  y = zeros(ComplexF64,N)
-
-  for l=1:N
-    for n=1:N
-      y[l] += x[n]*exp(-2*pi*im*(n-1)*(l-1)/N)
-    end   
-  end
-  return y
-end