You can reproduce some of the image processing described here with software today.<p>For example, in Figure 3, the histogram at the top right is a "periodogram" of the original image data. It shows that the original image is skewed towards the high end of the frequency spectrum. They apply a high-pass filter (discard the lowest frequencies) so the processed image shows higher details than the original.<p>If you had the original photograph as an image file, let's say an image of the surface of Mars, [0] you could filter out the lowest ten frequency components with a Python script: [1]<p><pre><code> pip install avena
avena filter high 10 pia19676-fig1_ml_mcam04403coloradjusted24bwscale.jpg
</code></pre>
The result: <a href="http://imgur.com/a/ASusx" rel="nofollow">http://imgur.com/a/ASusx</a><p>Notice the details are more visible.<p>[0] <a href="http://www.nasa.gov/jpl/msl/pia19676/geological-contact-zone-near-marias-pass-on-mars" rel="nofollow">http://www.nasa.gov/jpl/msl/pia19676/geological-contact-zone...</a><p>[1] (shameless plug) <a href="https://github.com/eliteraspberries/avena" rel="nofollow">https://github.com/eliteraspberries/avena</a>
About two years ago the Avaneya project released software that can decode the Viking Lander tapes. A few tapes contain images that were (as far as I know) never released.<p>Beautiful results: <a href="https://gist.github.com/jakeogh/fa995a3277d500ab59b1" rel="nofollow">https://gist.github.com/jakeogh/fa995a3277d500ab59b1</a><p>There's even a very nice DVD which takes the included raw tape data and processes it: <a href="https://directory.fsf.org/wiki/Avaneya:_Viking_Lander_Remastered_DVD" rel="nofollow">https://directory.fsf.org/wiki/Avaneya:_Viking_Lander_Remast...</a>