Hi Mark,
Just playing about with the non-sensical output from miriad's immerge on my M1, using the following python script:
Code: Select all
import numpy as np
from astropy.io import fits
import matplotlib.pylab as plt
fitsfile = 'merged.im.fits' # Non-sensical output of immerge as a fits
with fits.open(fitsfile) as hdul:
data = hdul[0].data[0] # Take 1st frequency channel as an example
img = np.fft.ifft2(data).real # Inverse Fourier transform the image
plt.close('all')
plt.imshow(img.real, vmin=0, cmap='plasma')
plt.savefig('immerged_ifft.png')
plt.show()
The resulting image is:
- immerged_ifft.png (145.15 KiB) Viewed 57945 times
From that image, it looks like there are two copies of the desired (I think?) result concatenated along the image x-axis. The left hand image appears inverted around the x-axis wrt the right hand image.
Further more, assuming immerge's output is still in the frequency domain, if I shift the image so the DC component is at the centre of the resultant array, and plot the results of the following python script:
Code: Select all
import numpy as np
from astropy.io import fits
import matplotlib.pylab as plt
fitsfile = 'merged.im.fits'
with fits.open(fitsfile) as hdul:
data = hdul[0].data[0] # Take 1st frequency channel
data = np.fft.fftshift(data)
plt.close('all')
plt.imshow(np.log10(np.abs(data)), cmap='plasma')
plt.savefig('immerged.png')
plt.show()
I get the following image in the frequency domain which is a little puzzling:
- immerged.png (203.17 KiB) Viewed 57945 times
