Description
Estamates the sharpness of one or more images by calculating the fraction of Fourier energy in the 16-4 pixel wavelength band. Computes the squared magnitude of the FFT for radii 0-256 pixels and then sums all coefficients from radii 32-128 pixels (for a 512 x 512 image). If run on a single file, prints a table of all radius/wavelength results and plots the log spectrum and log score. If run on a directory of files, prints final output sorted by sharpness that can be redirected to a text file.
Usage
sharpness.py directory [min-file-name] [max-file-name] [> output-file], or sharpness.py fits-file [min] [max]
Examples
10: ~/Projects/Python/AstroPy > sharpness.py 072407/processed/im0215.a.fits 0 1500 Min radius Max radius Max wavelength Min wavelength Count Score ---------- ---------- -------------- -------------- ----- ----- 0.00000000 8.00000000 512.00000000 64.00000000 197 0.88300450 8.00000000 16.00000000 64.00000000 32.00000000 600 0.08096362 16.00000000 24.00000000 32.00000000 21.33333333 996 0.02085621 24.00000000 32.00000000 21.33333333 16.00000000 1416 0.00666499 32.00000000 40.00000000 16.00000000 12.80000000 1816 0.00254313 40.00000000 48.00000000 12.80000000 10.66666667 2188 0.00117586 48.00000000 56.00000000 10.66666667 9.14285714 2632 0.00068950 56.00000000 64.00000000 9.14285714 8.00000000 3008 0.00052581 64.00000000 72.00000000 8.00000000 7.11111111 3388 0.00050236 72.00000000 80.00000000 7.11111111 6.40000000 3840 0.00042679 80.00000000 88.00000000 6.40000000 5.81818182 4232 0.00034603 88.00000000 96.00000000 5.81818182 5.33333333 4604 0.00026558 96.00000000 104.00000000 5.33333333 4.92307692 5032 0.00018962 104.00000000 112.00000000 4.92307692 4.57142857 5432 0.00015972 112.00000000 120.00000000 4.57142857 4.26666667 5844 0.00014614 120.00000000 128.00000000 4.26666667 4.00000000 6208 0.00015500 128.00000000 136.00000000 4.00000000 3.76470588 6656 0.00014452 136.00000000 144.00000000 3.76470588 3.55555556 7012 0.00014296 144.00000000 152.00000000 3.55555556 3.36842105 7432 0.00012782 152.00000000 160.00000000 3.36842105 3.20000000 7848 0.00010904 160.00000000 168.00000000 3.20000000 3.04761905 8252 0.00010008 168.00000000 176.00000000 3.04761905 2.90909091 8640 0.00008125 176.00000000 184.00000000 2.90909091 2.78260870 9080 0.00007212 184.00000000 192.00000000 2.78260870 2.66666667 9428 0.00006643 192.00000000 200.00000000 2.66666667 2.56000000 9848 0.00006889 200.00000000 208.00000000 2.56000000 2.46153846 10248 0.00006303 208.00000000 216.00000000 2.46153846 2.37037037 10628 0.00006123 216.00000000 224.00000000 2.37037037 2.28571429 11080 0.00005817 224.00000000 232.00000000 2.28571429 2.20689655 11464 0.00004983 232.00000000 240.00000000 2.20689655 2.13333333 11868 0.00004563 240.00000000 248.00000000 2.13333333 2.06451613 12288 0.00004974 248.00000000 256.00000000 2.06451613 2.00000000 12654 0.00014440 512 - 64: 0.88300450 64 - 32: 0.08096362 32 - 16: 0.02752120 16 - 8: 0.00493430 8 - 4: 0.00219123 4 - 2: 0.00138515 sharpness = 0.00712553 072407/processed/im0215.a.fits 2007-07-24 05:21:39.741545 0.00712553
The plot of log(fft data) x radius shows about 10% of all coefficients, chosen randomly. The peak about 2/3 in is at the 256 waves/frame (2 pixel wavelength) Nyquist limit (edge of FFT) while the remaining points to the right are from the corners and represent aliased values. Note that the points at left fall into the noise at about 64 w/f = 8 pixel wavelength, indicating that the bulk of the FFT for this image is superfluous (i.e. represents spacial waveforms < 8 pixels). This is in part why the sharpness is estimated in the 16-4 wavelength band, at the limit of seeing. Since the platescale for this image was about 0.12 arcsec/pixel, this indicates maximum resolution at a 4 pixel feature size, or about 0.48 arcsec.
13: ~/Projects/Python/AstroPy > sharpness.py 072407/processed im0195.a.fits im0249.a.fits 072407/processed/im0195.a.fits 2007-07-24 05:18:47.828235 0.00738312 072407/processed/im0215.a.fits 2007-07-24 05:21:39.741545 0.00712553 072407/processed/im0199.a.fits 2007-07-24 05:19:21.991239 0.00643756 072407/processed/im0198.a.fits 2007-07-24 05:19:13.462010 0.00593734 072407/processed/im0200.a.fits 2007-07-24 05:19:30.534879 0.00587662 072407/processed/im0212.a.fits 2007-07-24 05:21:13.980837 0.00545317 072407/processed/im0214.a.fits 2007-07-24 05:21:31.198092 0.00535011 072407/processed/im0201.a.fits 2007-07-24 05:19:39.811627 0.00522172 072407/processed/im0213.a.fits 2007-07-24 05:21:22.636515 0.00512398 072407/processed/im0209.a.fits 2007-07-24 05:20:48.091611 0.00507155 072407/processed/im0210.a.fits 2007-07-24 05:20:56.888271 0.00501898 072407/processed/im0203.a.fits 2007-07-24 05:19:56.853756 0.00500778 072407/processed/im0206.a.fits 2007-07-24 05:20:22.487024 0.00488715 072407/processed/im0211.a.fits 2007-07-24 05:21:05.446535 0.00483341 072407/processed/im0205.a.fits 2007-07-24 05:20:13.939939 0.00444530 072407/processed/im0207.a.fits 2007-07-24 05:20:31.220993 0.00444324 072407/processed/im0202.a.fits 2007-07-24 05:19:48.336848 0.00438618 072407/processed/im0236.a.fits 2007-07-24 05:24:39.361224 0.00414351 072407/processed/im0204.a.fits 2007-07-24 05:20:05.403290 0.00410755 072407/processed/im0237.a.fits 2007-07-24 05:24:47.730065 0.00403508 072407/processed/im0248.a.fits 2007-07-24 05:26:20.140111 0.00397225 072407/processed/im0216.a.fits 2007-07-24 05:21:48.256219 0.00382696 072407/processed/im0249.a.fits 2007-07-24 05:26:28.452767 0.00379972 072407/processed/im0235.a.fits 2007-07-24 05:24:31.021393 0.00370271 072407/processed/im0217.a.fits 2007-07-24 05:21:56.811459 0.00368754 072407/processed/im0208.a.fits 2007-07-24 05:20:39.554903 0.00367443 072407/processed/im0234.a.fits 2007-07-24 05:24:22.706379 0.00366863 072407/processed/im0244.a.fits 2007-07-24 05:25:46.369103 0.00357710 072407/processed/im0218.a.fits 2007-07-24 05:22:05.340763 0.00348124 072407/processed/im0221.a.fits 2007-07-24 05:22:31.364107 0.00341885 072407/processed/im0246.a.fits 2007-07-24 05:26:03.336123 0.00331917 072407/processed/im0240.a.fits 2007-07-24 05:25:12.832088 0.00331560 072407/processed/im0238.a.fits 2007-07-24 05:24:56.099255 0.00322886 072407/processed/im0242.a.fits 2007-07-24 05:25:29.473297 0.00318674 072407/processed/im0243.a.fits 2007-07-24 05:25:38.055761 0.00317211 072407/processed/im0232.a.fits 2007-07-24 05:24:05.508318 0.00314041 072407/processed/im0241.a.fits 2007-07-24 05:25:21.152264 0.00308917 072407/processed/im0247.a.fits 2007-07-24 05:26:11.817130 0.00305547 072407/processed/im0223.a.fits 2007-07-24 05:22:48.455309 0.00304300 072407/processed/im0239.a.fits 2007-07-24 05:25:04.443991 0.00303232 072407/processed/im0230.a.fits 2007-07-24 05:23:48.890655 0.00302305 072407/processed/im0226.a.fits 2007-07-24 05:23:14.857588 0.00300760 072407/processed/im0233.a.fits 2007-07-24 05:24:14.101626 0.00290879 072407/processed/im0222.a.fits 2007-07-24 05:22:40.086394 0.00287185 072407/processed/im0245.a.fits 2007-07-24 05:25:54.780446 0.00286915 072407/processed/im0229.a.fits 2007-07-24 05:23:40.320614 0.00282609 072407/processed/im0220.a.fits 2007-07-24 05:22:22.784924 0.00281968 072407/processed/im0227.a.fits 2007-07-24 05:23:23.636095 0.00265883 072407/processed/im0228.a.fits 2007-07-24 05:23:31.980564 0.00264786 072407/processed/im0224.a.fits 2007-07-24 05:22:57.698819 0.00256280 072407/processed/im0225.a.fits 2007-07-24 05:23:06.269180 0.00249372 072407/processed/im0231.a.fits 2007-07-24 05:23:57.198956 0.00241051 072407/processed/im0219.a.fits 2007-07-24 05:22:14.219079 0.00235148
The 3 sharpest images in this result are:
The 3 middle-sharp images are:
The 3 blurriest images are:
İSky Coyote 2007