def elliptical():
    """Generate a test image with random ellipses and background noise."""
    im = TestImage(shift=True, nx=1000, ny=1000)
    im.addEllipseRandom(nEllipse=100, value=5)
    im.addNoise(sigma=1)
    im.hanningFilter()
    #im.zeroPad()
    im.calcAll(min_npix=2, min_dr=1)
    im.plotMore()
    pylab.savefig('elliptical.%s' %(figformat), format='%s' %(figformat))
    # Invert from ACovF 1d without phases                                             
    im.invertAcovf1d()
    im.invertAcovf2d(useI=True)
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)
    im.showImageAndImageI()
    pylab.savefig('elliptical_invert.%s' %(figformat), format='%s' %(figformat))
    pylab.close()
    return
def inversion():
    """Generate some example images & invert them to reconstruct the original image."""
    im = TestImage(shift=True, nx=1000, ny=1000)
    #im.addEllipseGrid(gridX=200, gridY=100, semiX=50, semiY=25, value=1)
    im.addLines(width=20, spacing=200, value=1, angle=45)
    im.addSin(scale=300)
    im.hanningFilter()
    im.zeroPad()
    #cmap = pylab.cm.gray_r
    cmap = None
    clims = im.showImage(cmap=cmap)
    pylab.savefig('invert_image.%s' %(figformat), format='%s' %(figformat))
    im.calcAll(min_npix=1, min_dr=1)
    # Invert from ACovF and show perfect reconstruction.
    im.invertAcovf2d()
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_acovf2d_good.%s' %(figformat), format='%s' %(figformat))
    # Invert from ACovF 2d without phases
    im.invertAcovf2d(usePhasespec=False, seed=42)
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)    
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_acovf2d_nophases.%s' %(figformat), format='%s' %(figformat))
    # Invert from ACovF 1d with phases
    im.invertAcovf1d(phasespec=im.phasespec)
    im.invertAcovf2d(useI=True)
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_acovf1d_phases.%s' %(figformat), format='%s' %(figformat))
    # Invert from ACovF 1d without phases
    im.invertAcovf1d(seed=42)
    im.invertAcovf2d(useI=True)
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_acovf1d_nophases.%s' %(figformat), format='%s' %(figformat))
    # Recalculate 1-d PSD and ACovF from this last reconstructed image (ACovF1d no phases)
    im2 = PImagePlots()
    im2.setImage(im.imageI)
    im2.calcAll(min_npix=1, min_dr=1)
    legendlabels=['Reconstructed', 'Original']
    im2.showPsd1d(comparison=im, legendlabels=legendlabels)
    pylab.savefig('invert_recalc_ACovF_Psd1d.%s' %(figformat), format='%s' %(figformat))
    im2.showAcovf1d(comparison=im, legendlabels=legendlabels)
    pylab.savefig('invert_recalc_ACovF_Acovf1d.%s' %(figformat), format='%s' %(figformat))
    # Invert from PSD and show perfect reconstruction.                          
    im.invertPsd2d()
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_psd2d_good.%s' %(figformat), format='%s' %(figformat))
    # Invert from PSD 2d without phases
    im.invertPsd2d(usePhasespec=False, seed=42)
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_psd2d_nophases.%s' %(figformat), format='%s' %(figformat))
    # Invert from PSD 1d with phases                                   
    im.invertPsd1d(phasespec=im.phasespec)
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_psd1d_phases.%s' %(figformat), format='%s' %(figformat))
    # Invert from PSD 1d without phases                                             
    im.invertPsd1d(seed=42)
    im.invertPsd2d(useI=True)
    im.invertFft(useI=True)
    im.showImageI(clims=clims, cmap=cmap)
    pylab.savefig('invert_psd1d_nophases.%s' %(figformat), format='%s' %(figformat))
    # Recalculate 1-d PSD and ACovF from this last reconstructed image (PSD1d no phases)
    im2 = PImagePlots()
    im2.setImage(im.imageI)
    im2.calcAll(min_npix=1, min_dr=1)
    im2.showPsd1d(comparison=im, legendlabels=legendlabels)
    pylab.savefig('invert_recalc_PSD_Psd1d.%s' %(figformat), format='%s' %(figformat))
    im2.showAcovf1d(comparison=im, legendlabels=legendlabels)
    pylab.savefig('invert_recalc_PSD_Acovf1d.%s' %(figformat), format='%s' %(figformat))
    pylab.close()
    return