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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part Bl. Istanbul 2004 
IHS fusion images illustrated generally clearer sharpness, it 
was identified that wavelet fusion images were more excellent 
in smoothness or resolutions of overall gray scales. In particular, 
noise was observed on areas with extremely high brightness in 
HIS fusion images. On the contrary, two methods had similar 
resolutions in mountain areas, but also had noises. For 
comparing resolutions between images obtained from a 
developed program for Wavelet method and fusion images 
using Mathlab library, bridge areas and residential areas were 
enlarged as shown in Figure 10. The definite differences of 
resolution differences were visually indicated. In particular, 
resolutions were significant for linear structures such as bridges. 
Gray scales in Wavelet fusion method had to be 0-255, but they 
were actually less than 0 and over 255. Therefore, a developed 
program applied stretching to gray scales to be within the range 
of 0-255. In Mathlab, values below and over 255 were 
ignored in calculation. Therefore, these adjustments could be 
the reason for differences in sharpness. 
5.2.2 Visual Analysis 
Roofs of primary colors, streams, roads, forests and grey 
roofs were mainly analyzed for each fusion method. IHS fusion 
method was useful for grey roofs, roads and streams and 
Wavelet fusion method demonstrated superior results on green 
color series, grey roofs, roads and streams. PCA method was 
excellent for streams, yellow roofs and red roofs. In general, 
Wavelet method was the most appropriate followed by IHS and 
HPF method according to applications. 
5.2.3 Brightness Range by Band 
  
- M E1250-300 
5 NT V " la B 200-250 
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b)HIS method 
Figurell Red Level in Sampling of Wavelet Fusion Images 
Brightness by band of images created by IHS and Wavelet 
fusion method was examined. Sampling was conducted every 
l6-pixel on an entire image and brightness was extracted. 
Among brightness, red level was presented. 
For red levels in two fusion methods, IHS fusion images 
demonstrated generally wider distribution ranges as compared 
to Wavelet method. Moreover, since Wavelet images had wider 
brightness range, smooth images were obtained. Average 
brightness of IHS and Wavelet method was 125 and 123, 
respectively. IHS images had generally broader green band 
distribution range. Green band range of Wavelet and IHS was 
122 and 123, respectively. Blue band also showed similar 
patterns as Red and Green band. With respect of distribution 
ranges, blue bánd was distributed the most in 150-200 and next 
in 50-100. 
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a) Wavelet Red value-IHS Red value 
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b) Wavelet Green value-IHS Green value 
Grey value difference 
  
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c) Wavelet Blue value-IHS Blue value 
Figure 12 Grey level difference after Wavelet method and HIS 
method.