The main purpose of this lab was to familiarize us with the use of several different image reprocessing tools. The main skills that were emphasized in this lab were
1. Understand how to take a subset of a larger image
2. Understand pan-sharpening, and how to increase spatial resolution
3. Understand radiometric enhancement techniques
4. Understand how to link an image to Google Earth, and how this can be useful
5. Understand how to resample satellite images
All of the data used in the lab was made available our Lab 4 folder
Methods
1. Understand how to take a subset of a larger image: In order to achieve this, I used the Subset & Clip tool to create subset image. When I had a specific area that I needed to subset I inserted the shapefile of the desired area, selected the shapefile and clicked on paste from selected object. Then I was able to make an area of interest which could be designated as the subset image.
2. Understand pan-sharpening, and how to increase spatial resolution: For the pan-sharpening, I went to Pan Sharpen and clicked on resolution merge. From there I defined what was the high resolution image, what was the multispectral image, and what I wanted the output file to be.
3. Understand radiometric enhancement techniques: For the image in question there was a bit of haze, so I clicked on radiometric and went to Haze reduction and designated a file for the output image.
4. Understand how to link an image to Google Earth, and how this can be useful: For this section I clicked on Connect to Google Earth and then linked the image that I had in my viewer to Google earth. Using it, I was able to see what the features were that I was actually looking at, because Google earth had high spectral areal photos where the features were more obvious.
5. Understand how to resample satellite images: For this section I clicked on Spatial and then clicked on Resample pixel size. I tried two different resampling techniques and noticed that nearest neighbor was virtually indistinguishable from the original, while bilinear interpolation produced an image with much smoother lines.
Results
Below are the images that I produced during the Lab
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| Image Subset |
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| Image subset from Area of Interest |
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| Haze reduction image |
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| Pan-sharpened image |
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| Nearest Neighbor resampled image |
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| Bilinear Interpolation resampled image |
All images were provided in our Lab 4 folders
All image editing was done in Erdas Imagine
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