A8.C - Lunar Landing Scanned Pictures : Line removal

Yey! for another exercise that makes use of what we have learned about FTs.

Basically, we want to enhance this image of the moon's surface by removing the lines that are not supposed to be part of the image.

So given this image of the moon's surface...

Figure 1: Moon's surface
from: http://www.lpi.usra.edu/lunar/missions/apollo/apollo_11/images

we take its FT...

Figure 2: FT of moon's surface image

-we know that when we inverse a crossed-shaped FT, this would results to square patterns. Therefore this corresponds to the lines that we want to remove. From this...

...a filter is designed as...

Figure 3: Filter

To select only the areas we want to retain, we multiply the FT with the filter that we designed...

Figure 4: FT multiplied by filter

Taking the inverse of figure 4 results to...

Figure 5: Enhanced image

...which is an enhanced image of the moon's surface(without the lines)...yey!!! :D

CODE: same as activity A8.B with the filter input being image illustrated by figure 3.