using image fusion and classification to profile a human ... - asprs

RESULTS
The image fusion between the Quickbird PAN image and the MS image was successful using the Ehlers and the
SRM pan sharpening algorithms. The fused images provide some definite advantages for combining high spatial
and high spectral resolution imagery. One major difference between the fused images and the original MS image is
the pixel resolution, where the fused images have a 65 cm resolution compared to the original MS image at 2.5
meters. Consequently, this resulted in different pixel classifications for each image based on the roof training class.
A sub-pixel classifier was used to identify all of the pixels in the image that are of the same category of roof training
class. Table 2 summarizes the percentage of correct pixels, based on 10 randomly selected roof structures spread
throughout the scene, for each original MS image and each fused image. Table 3 shows the percentages of incorrectly
identified pixels, based on a different 10 random locations spread throughout the scene. The percentages
were estimated by visual quantative analysis of each area.
Table 2. Percentage of Correctly Identified Pixels
Location Original MS
Image
Ehlers Fusion SRM Fusion
1 55 95 80
2 60 95 80
3 45 90 70
4 90 95 85
5 80 95 90
6 60 80 50
7 60 50 55
8 40 95 75
9 85 95 65
10 20 80 10
Average % Correct 60% 87% 66%
Table 3. Percentage of IN-Correctly Identified Pixels
Location Original
MS Image
Ehlers Fusion SRM Fusion
1 80 90 85
2 85 70 80
3 5 60 5
4 75 55 0
5 0 0 0
6 70 50 5
7 5 0 0
8 0 10 0
9 0 5 5
10 0 0 0
Average % IN-Correct 32% 34% 18%
Table 2 indicates the Ehlers Fusion algorithm outperformed the SRM method and the original MS image by a
significant margin, based on the average percentage of correctly identified pixels. The SRM method did marginally
better than the original MS image, even though the spatial resolution is much better. It is important to remember the
fused images have a pixel resolution of 65 cm, whereas, the original MS image is at 2.5 meters. So, it is conceivable
Pecora 18 –Forty Years of Earth Observation...Understanding a Changing World November 14 – 17,
2011Herndon, Virginia