i.vi: fix formatting (#2007)

fixes #1998

- typo introduced in 6fb6afd
- C formatting

imagery/i.vi/ci.c

@@ -6,18 +6,16 @@
  * Crust Index CI=1-(RED-BLUE)/(RED+BLUE). (KARNIELI, 1997)
  * Development and implementation of spectral crust index over dune sands
  * The Remote Sensing Laboratory, J. Blaustein Institute for Desert Research, Ben Gurion University, Sede-Boker Campus 84990, Israel. (Received 26 January 1996; in ® nal form 19 July 1996) */
-    /* Crust Index */ 
-double c_i(double bluechan, double redchan) 
+    /* Crust Index */
+double c_i(double bluechan, double redchan)
 {
     double result;
 
     if ((redchan + bluechan) == 0.0) {
-	result = -1.0;
+        result = -1.0;
     }
     else {
-	result = 1 - (redchan - bluechan) / (redchan + bluechan);
+        result = 1 - (redchan - bluechan) / (redchan + bluechan);
     }
     return result;
 }
-
-

imagery/i.vi/i.vi.html

@@ -82,12 +82,13 @@ <h3>Vegetation Indices</h3>
 
 <b>CI: Crust Index</b> 
 <p>
-Advantage is taken of a unique spectral feature of soil biogenic
-crust containing cyanobacteria. It has been shown that the special phycobilin
-pigment in cyanobacteria contributes in producing a relatively higher re ̄ ectance
-in the blue spectral region than the same type of substrate without the
-biogenic crust. The spectral crust index (CI) is based on
-the normalized difference between the RED and the BLUE spectral values (Karnieli, 1997).
+Advantage is taken of a unique spectral feature of soil biogenic crust
+containing cyanobacteria. It has been shown that the special phycobilin
+pigment in cyanobacteria contributes in producing a relatively higher
+reflectance in the blue spectral region than the same type of substrate
+without the biogenic crust. The spectral crust index (CI) is based on
+the normalized difference between the RED and the BLUE spectral values
+(Karnieli, 1997, DOI: 10.1080/014311697218368).
 
 <div class="code"><pre>
 ci ( bluechan, redchan )