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The two files to download have the same format as the moon.txt so whatever procedure that you used on that file to build the intensity array will work here.
Steps:
- Download the two files
- Using any procedure that you can think of, automatically determine the positions of the stars in the Stars image. Then using any procedure that you can think of, measure the integrated brightness (intensity) of these identified stars.
Using the High charts Bubble Chart with JS Fiddle produce a bubble chart showing the x,y center of the star and the radius of the bubble should correspond to the star's integrated brightness
- All the rest of the steps will use the Galaxy file. Note that when you try to display the galaxy file in something like Imagemagick (default on aciss) you might not see the actual galaxy as there are two bright stars that dominate the contrast. There are many ways around this but you should endeavor to simply edit those positions out of the data array.
- From the center of the galaxy (identify that any way that you like) Compute the average brightness of the galaxy in annular rings of width 5 pixels and spaced by 20 pixels from the center to the edge and Make a plot of radius vs ring brightness and attempt to fit a functional representation of that relation to the data
- Produce a histogram of the pixel values and suggest a reason for the particular form of the histogram
- Read about the Histogram_equalization technique and apply that transformation to the image array. Produce images of the Galaxy before and after applying the Histogram equalization transform (what the Wikipedia article says about the originator of this idea is incorrect - lots of people thought of this).
- Make the Galaxy disappear. Using any random number generator approach that you like, make the galaxy disappear by adding sufficient random noise to the image. Include a picture of the disappeared galaxy
Bonus question: What does this tell you about our ability to detect galaxies?
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