public void ShiftNoShiftSameFft()
{
// Expectation
// INVFFT(SHIFTEDFFT(IMG) * SHIFTEDFILTER) == INVFFT(FFT(IMG) * FILTER)
IImage <double> bunny = ImageFactory.Generate(BunnyPath)
.Crop(0, 0, 512, 512);
// Shift and NoShift FFT
var noShiftFft = bunny.Fft(false);
var shiftFft = bunny.Fft(true);
// Shift and NoShift Filter
var noShiftfilter = Filters.MakeFilter(512, 512, Filters.IdealLowPass(50));
var shiftFilter = Filters.MakeFilterWithOffset(512, 512, Filters.IdealLowPass(50));
// Multiply Filter by FFT
IImage <Complex> shift = ImageFactory.GenerateComplex(512, 512);
IImage <Complex> noShift = ImageFactory.GenerateComplex(512, 512);
Parallel.For(0, bunny.Length, i =>
{
shift[i] = shiftFilter[i] * shiftFft[i];
noShift[i] = noShiftfilter[i] * noShiftFft[i];
});
// Get Inverse FFT
var shiftResult = shift.InverseFft();
var noShiftResult = noShift.InverseFft();
Assert.IsTrue(ImagesEqualWithinEpsilon(noShiftResult, shiftResult, (x, y) => Math.Abs(x - y) < 0.05));
}
public void TestFFT()
{
// [512 * 512] image
IImage <double> bun = ImageFactory
.Generate(ImageTests.BunnyPath)
.Crop(0, 0, 512, 512);
Assert.IsTrue(bun.Height == 512);
Assert.IsTrue(bun.Width == 512);
// Fast Forrier Transform
IImage <Complex> fft = bun.Fft();
IImage <double> realPart = fft.RealPart();
IImage <double> imagPart = fft.ImaginaryPart();
Assert.IsFalse(ImageEmpty(realPart));
Assert.IsFalse(ImageEmpty(imagPart));
Assert.IsTrue(realPart.Width == imagPart.Width);
Assert.IsTrue(realPart.Height == imagPart.Height);
// IMAGINARY(COMPLEX) + REAL(COMPLEX) == COMPLEX
IImage <Complex> fftEq = ImageFactory
.GenerateComplex(512, 512, realPart.Zip(imagPart, (real, img) => new Complex(real, img)));
Assert.IsTrue(ImagesEqual(fft, fftEq));
realPart
.WriteImage(Path.Combine(WorkingDirectory, "FFT RealPart"));
imagPart
.WriteImage(Path.Combine(WorkingDirectory, "FFT ImaginaryPart"));
fft
.Phase()
.WriteImage(Path.Combine(WorkingDirectory, "FFT Phase"));
fft
.MagnitudePart()
.WriteImage(Path.Combine(WorkingDirectory, "FFT Magnitude"));
fft
.InverseFft()
.WriteImage(Path.Combine(WorkingDirectory, "FFT Inverse FFT"));
}
public void TestHarmonicSignal()
{
ImageFactory.GenerateComplex(128, 128)
.MapLocation(Filters.HarmonicSignal((3.0 / 128.0), (2.0 / 128.0)))
.WriteImage(WorkingDirectory, "Complex Harmonic");
}
public void TestClearComplex()
{
ImageFactory.GenerateComplex(50, 50).Clear();
}
public void TestIsSynchronizedComplex()
{
Assert.IsFalse(ImageFactory.GenerateComplex(50, 50).IsSynchronized);
}
public void TestIsReadOnlyComplex()
{
Assert.IsTrue(ImageFactory.GenerateComplex(50, 50).IsReadOnly);
}
public void TestAddComplex()
{
ImageFactory.GenerateComplex(50, 50).Add(default(Complex));
}
public void TestRemoveComplex()
{
ImageFactory.GenerateComplex(50, 50).Remove(default(Complex));
}