Geografic-Information-System/scripts/i.fusion.brovey/i.fusion.brovey.html

<H2>DESCRIPTION</H2>

<EM>i.fusion.brovey</EM> performs a Brovey transformation using
three multispectral and the panchromatic satellite image scene 
channels. Three new channels are calculated according to the
formula:

<pre>
                            DN_b1 
    DN_fused = ------------------------------- * DN_pan
                    DN_b1 + DN_b2 + DN_b3
</pre>

The assignment of the channels depends on the satellite.
The module's help text (above) suggests for LANDSAT-7, QuickBird and SPOT.


<H2>NOTES</H2>
The command changes temporarily to the high resolution of the
panchromatic channels for creating the three output channels,
then restores the previous region settings. The current
region coordinates are respected. The three pan-sharpened output
channels may be combined with <em>d.rgb</em> or <em>r.composite</em>.


<H2>EXAMPLE</H2>

Calculation of Brovey fusion map from North Carolina Landsat scene:

<div class="code"><pre>
g.region rast=lsat7_2002_20 -p

# R, G, B composite at 28.5m 
d.rgb b=lsat7_2002_10 g=lsat7_2002_20 r=lsat7_2002_30

# Brovey fusion
i.fusion.brovey -l ms1=lsat7_2002_20 ms2=lsat7_2002_40 \
                   ms3=lsat7_2002_50 pan=lsat7_2002_80 \
                   outputprefix=brovey

# display at 14.25m
g.region rast=brovey.blue -p
d.rgb b=brovey.blue g=brovey.green r=brovey.red
</pre></div>


Results:

<p>
<center>
  <table border=1>
  <tr>
    <td align=center>
      &nbsp;<img src="rgb_originals.jpg" alt="R, G, B composite of Landsat at 28.5m">
      <br>
      <font size="-1">
      <i>R, G, B composite of Landsat at 28.5m</i>
      </font>
    </td>
    <td align=center>
      &nbsp;<img src="rgb_brovey.jpg" alt="R, G, B composite of Landsat Brovey fusion at 14.25m">
      <br>
      <font size="-1">
      <i>R, G, B composite of Landsat Brovey fusion at 14.25m</i>
      </font>
    </td>
  </tr>
  </table>
</center>
<br>


Colors may be optionally optimized.


<H2>SEE ALSO</H2>

<EM>
<A HREF="i.his.rgb.html">i.his.rgb</A>,
<A HREF="i.rgb.his.html">i.rgb.his</A>,
<A HREF="d.rgb.html">d.rgb</A>,
<A HREF="r.composite.html">r.composite</A>
</EM>


<H2>REFERENCES</H2>

<ul>
<li>Original Brovey formula reference unknown, probably <br>
   Roller, N.E.G. and Cox, S., 1980. Comparison of Landsat MSS
   and merged MSS/RBV data for analysis of natural vegetation.
   Proc. of the 14th International Symposium on Remote Sensing
   of Environment, San Jose, Costa Rica, 23-30 April, pp. 1001-1007

<li>Pohl, C., and J.L. van Genderen, 1998. 
    Multisensor image fusion in remote sensing: concepts, methods and
    application. Int. J. of Rem. Sens., 19, 823-854.

<li>M. Neteler, D. Grasso, I. Michelazzi, L. Miori, S. Merler, and C.
   Furlanello, 2005.
   An integrated toolbox for image registration, fusion and classification.
   International Journal of Geoinformatics, 1(1):51-61
   (<a href="http://www.grassbook.org/neteler/papers/neteler2005_IJG_051-061_draft.pdf">PDF</a>)
</ul>


<H2>AUTHOR</H2>

Markus Neteler, ITC-irst, Italy
<p>
<i>Last changed: $Date$</i>