Process
Summary Details
Exercise
1:
NOTES:
1.
Retrieving
the data files from the website was at first difficult, until I used a proper
browser and made sure that the Java extension was up to date. Otherwise, I did
not run into too many problems when it came to downloading the image of
Pensacola Bay. As instructed, I closed browser and used the image provided in
the zipped folder of Module 6 content.
2.
I
unzipped both files required for this task, and opened them in Erdas imagine by
importing them according to instructions.
Exercise
2:
NOTES:
1.
I
began by adding p011r061_nn80 to a main project in Erdas Imagine. When I applied the 3x3 low pass
Kernel filter (using the Convolution tool), the image seemed overall brighter.
The edges of individual features were not at all distinguishable, but larger ‘bulk’
features could be seen quite prominently. I repeated the same steps in the
convolution tool, but instead filtered the image through a 3x3 high pass
filter. Smaller individual features became a lot more defined and easy to see,
but boundaries of larger areas became more difficult to define.
2.
I
opened the same image in ArcMap, and used the Focal Statistics tool according
to directions. The raster set created used the “Mean” statistical filter. It
was filtered through the 7x7 Kernel (instead of 3x3 cells,) therefore the image
came out looking less defined than before.
3.
Once
again, I used the Focal Statistics tool to open the same image, this time
through a 3x3 Kernel and with the statistical filter for “Range” which is often
used to define edges in features by highlighting the difference in brightness
between neighboring pixels and feature in question.
Exercise
3:
Write down
every enhancement process that you run on this image, and describe any
noticeable effects of each. (Consider
this the most important part of the process summary – there should be a lot of
detail here.)
NOTES:
1.
I
came back to Erdas Imagine for the final task of this lab.
2.
I
opened the l7_striping.img file as directed in the assignment. The image appeared visible and
perfectly fine.
3.
I
went into the raster tab and clicked on “scientific” under group.
4.
I
clicked into Fourier Analysis and selected the Fourier Transform Editor.
5.
I
opened the l7_striping.fft file and explored the image. It appeared as a several light lines of
star-like images of varied radiance, stretching diagonally from the top to the
bottom of the image.
6.
I
scrolled all the way up on the image, and over to the center-top as directed.
7.
I
used the wedge tool by selecting it, and clicking at the center of the
upper-most star in the middle row and moving the mouse cursor over to expand
the “V” shape. The first attempt created a very thin band. I figured that it
would not be sufficient to mask the striping effect, so I clicked undo and
tired again.
8.
The
second time around, I attempted to create a much larger “V” shape, but it still
came out slightly thinner than the one shown on the screen shot in the module 6
directions. I decided to keep it for the times being, and see what the striping
might look like after application.
9.
Afterwards,
I scrolled down to the very center of the image and selected the LowPass
button. I held down the left mouse key over the center of the image, and
extended a circle to the very edge of the screen. The resulting image was a
very bright sphere; fading out at the edges, with two long triangular features
extending from the center and out towards the edges.
10. When I compared the finished product
to the sample presented ion the assignment, I thought it to be quite similar.
11. I saved as Fourier1.fft, and
used the Run tool to create a new Img file. When I opened it in Erdas, the file
seems to have been created successfully.
12. Back in Erdas, under the Raster tab and
Resolution group I selected Spatial-Convolution.
13. I selected Fourier1.img as the input
file and selected 3x3 Sharpen in the Kernel menu. I ran the filter. The Sharpen
image seemed quite almost exactly the same, but the definition was slightly
superior.
14. I tried repeating the process and
obtained following results when choosing the filter;
a. 11x11 LowPass – image was very blurry
and difficult to interpret.
b. 3x3 Edge Enhance – image became very
uniformly grey, and the lines became darker and quite pronounced.
c. 5x5 High Pass – Image became very
dark, and only larger features became all grey in color. Very difficult to
read.
d. 3x3 Haze Reduction – Fairly readable,
but the dark lines become awfully thick on the left side
of the image.
e. 3x3 Sobel – Image became
monochromatic, and much too dark.
15. After many attempts, I decided to use
my initial ‘sharpen1’ file from the early stage of the assignment.
16. I added the essential map elements,
after importing the raster file into ArcMap saved my lab assignment.
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