Added i.vi

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@33581 15284696-431f-4ddb-bdfa-cd5b030d7da7

imagery/i.vi/Makefile

@@ -0,0 +1,14 @@
+MODULE_TOPDIR = ../..
+
+PGM = i.vi
+
+LIBES = $(GISLIB)
+DEPENDENCIES = $(GISDEP)
+
+include $(MODULE_TOPDIR)/include/Make/Module.make
+
+ifneq ($(USE_LARGEFILES),)
+	EXTRA_CFLAGS = -D_FILE_OFFSET_BITS=64
+endif
+
+default: cmd

imagery/i.vi/arvi.c

@@ -0,0 +1,26 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+ 
+    /*  ARVI is resistant to atmospheric effects (in comparison to the NDVI) and 
+       is accomplished by a self correcting process for the atmospheric effect in the
+       red channel, using the difference in the radiance between the blue and the red channels. 
+       (Kaufman and Tanre 1996) */ 
+    
+    /* Atmospheric Resistant Vegetation Index */ 
+double ar_vi(double redchan, double nirchan, double bluechan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result =
+	    (nirchan - (2 * redchan - bluechan)) / (nirchan +
+						    (2 * redchan - bluechan));
+    }
+    return result;
+}
+
+

imagery/i.vi/dvi.c

@@ -0,0 +1,19 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* DVI: Difference Vegetation Index */ 
+double d_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = (nirchan - redchan);
+    }
+    return result;
+}
+
+

imagery/i.vi/evi.c

@@ -0,0 +1,24 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* EVI: Enhanced Vegetation Index
+     * Huete A.R., Liu H.Q., Batchily K., vanLeeuwen W. (1997)
+     * A comparison of vegetation indices global set of TM images for EOS-MODIS
+     * Remote Sensing of Environment, 59:440-451.
+     */ 
+double e_vi(double bluechan, double redchan, double nirchan) 
+{
+    double tmp, result;
+
+    tmp = nirchan + 6.0 * redchan - 7.5 * bluechan + 1.0;
+    if (tmp == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = 2.5 * (nirchan - redchan) / tmp;
+    }
+    return result;
+}
+
+

imagery/i.vi/gari.c

@@ -0,0 +1,20 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /*GARI: green atmospherically resistant vegetation index */ 
+double ga_ri(double redchan, double nirchan, double bluechan,
+	      double greenchan) 
+{
+    double result;
+
+     {
+	result =
+	    (nirchan - (greenchan - (bluechan - redchan))) / (nirchan -
+							      (greenchan -
+							       (bluechan -
+								redchan)));
+    } return result;
+}
+
+

imagery/i.vi/gemi.c

@@ -0,0 +1,36 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* GEMI: Global Environmental Monitoring Index
+     */ 
+double ge_mi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result =
+	    (((2 * ((nirchan * nirchan) - (redchan * redchan)) +
+	       1.5 * nirchan + 0.5 * redchan) / (nirchan + redchan +
+						 0.5)) * (1 -
+							  0.25 * (2 *
+								  ((nirchan *
+								    nirchan) -
+								   (redchan *
+								    redchan))
+								  +
+								  1.5 *
+								  nirchan +
+								  0.5 *
+								  redchan) /
+							  (nirchan + redchan +
+							   0.5))) -
+	    ((redchan - 0.125) / (1 - redchan));
+    }
+    return result;
+}
+
+

imagery/i.vi/gvi.c

@@ -0,0 +1,23 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* Green Vegetation Index */ 
+double g_vi(double bluechan, double greenchan, double redchan,
+	      double nirchan, double chan5chan, double chan7chan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else
+	 {
+	result =
+	    (-0.2848 * bluechan - 0.2435 * greenchan - 0.5436 * redchan +
+	     0.7243 * nirchan + 0.0840 * chan5chan - 0.1800 * chan7chan);
+	}
+    return result;
+}
+
+

imagery/i.vi/i.vi.html

@@ -0,0 +1,60 @@
+<H2>DESCRIPTION</H2>
+
+<EM>i.vi</EM> calculates vegetation indices based on biophysical parameters. 
+
+1. RVI: ratio vegetation index: 
+2. NDVI: Normalized Difference Vegetation Index
+3: IPVI: Infrared Percentage Vegetation Index
+4: DVI: Difference Vegetation Index
+5: PVI: Perpendicular Vegetation Index
+6: WDVI: Weighted Difference Vegetation Index
+7: SAVI: Soil Adjusted Vegetation Index 
+8: GARI: Green atmospherically resistant vegetation index
+9: MSAVI: Modified Soil Adjusted Vegetation Index
+10:MSAVI2: second Modified Soil Adjusted Vegetation Index
+11:GEMI: Global Environmental Monitoring Index
+12:ARVI: atmospherically resistant vegetation indices
+13:GVI: Green Vegetation Index
+
+NDVI 
+Data Type Band Numbers ([IR, Red]) 
+TM Bands= [4,3] 
+MSS Bands = [7, 5] 
+AVHRR Bands = [2, 1] 
+SPOT XS Bands = [3, 2] 
+AVIRIS Bands = [51, 29] 
+
+
+(AVHRR) NDVI = (channel 2 - channel 1) / (channel 2 + channel 1)
+
+
+<H2>NOTES</H2>
+Originally from kepler.gps.caltech.edu
+A FAQ on Vegetation in Remote Sensing 
+Written by Terrill W. Ray
+	   Div. of Geological and Planetary Sciences
+	   California Institute of Technology
+email: terrill@mars1.gps.caltech.edu
+Snail Mail:  Terrill Ray
+	     Division of Geological and Planetary Sciences
+	     Caltech
+	     Mail Code 170-25
+	     Pasadena, CA  91125
+
+<H2>TODO</H2>
+
+
+<H2>SEE ALSO</H2>
+
+<em>
+<A HREF="i.albedo.html">i.albedo</A><br>
+</em>
+
+
+<H2>AUTHORS</H2>
+Baburao Kamble, Asian Institute of Technology, Thailand<BR>
+Yann Chemin, Asian Institute of Technology, Thailand<BR>
+
+
+<p>
+<i>Last changed: $Date: 2006/10/09 21:30:42 $</i>

imagery/i.vi/ipvi.c

@@ -0,0 +1,25 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /*
+       IPVI: Infrared Percentage Vegetation Index
+       
+       NIR
+       IPVI = --------
+       NIR+red
+     */ 
+double ip_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = (nirchan) / (nirchan + redchan);
+    }
+    return result;
+}
+
+

imagery/i.vi/main.c

@@ -0,0 +1,576 @@
+
+/****************************************************************************
+ *
+ * MODULE:       i.vi
+ * AUTHOR(S):    Baburao Kamble baburaokamble@gmail.com
+ *		 Yann Chemin - yann.chemin@gmail.com
+ * PURPOSE:      Calculates 14 vegetation indices 
+ * 		 based on biophysical parameters. 
+ *
+ * COPYRIGHT:    (C) 2002-2008 by the GRASS Development Team
+ *
+ *               This program is free software under the GNU General Public
+ *   	    	 License (>=v2). Read the file COPYING that comes with GRASS
+ *   	    	 for details.
+ * 
+ * Remark:              
+ *		 These are generic indices that use red and nir for most of them. 
+ *               Those can be any use by standard satellite having V and IR.
+ *		 However arvi uses red, nir and blue; 
+ *		 GVI uses B,G,R,NIR, chan5 and chan 7 of landsat;
+ *		 and GARI uses B,G,R and NIR.   
+ *
+ * Changelog:	 Added EVI on 20080718 (Yann)
+ *
+ *****************************************************************************/
+ 
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <grass/gis.h>
+#include <grass/glocale.h>
+double s_r(double redchan, double nirchan);
+
+double nd_vi(double redchan, double nirchan);
+
+double ip_vi(double redchan, double nirchan);
+
+double d_vi(double redchan, double nirchan);
+
+double e_vi(double bluechan, double redchan, double nirchan);
+
+double p_vi(double redchan, double nirchan);
+
+double wd_vi(double redchan, double nirchan);
+
+double sa_vi(double redchan, double nirchan);
+
+double msa_vi(double redchan, double nirchan);
+
+double msa_vi2(double redchan, double nirchan);
+
+double ge_mi(double redchan, double nirchan);
+
+double ar_vi(double redchan, double nirchan, double bluechan);
+
+double g_vi(double bluechan, double greenchan, double redchan,
+	     double nirchan, double chan5chan, double chan7chan);
+double ga_ri(double redchan, double nirchan, double bluechan,
+	      double greenchan);
+int main(int argc, char *argv[]) 
+{
+    struct Cell_head cellhd;	/*region+header info */
+
+    char *mapset;		/*mapset name */
+
+    int nrows, ncols;
+
+    int row, col;
+
+    char *viflag;		/*Switch for particular index */
+
+    struct GModule *module;
+
+    struct Option *input1, *input2, *input3, *input4, *input5, *input6,
+	*input7, *output;
+    struct Flag *flag1;
+
+    struct History history;	/*metadata */
+
+    struct Colors colors;	/*Color rules */
+
+    
+
+	/************************************/ 
+	/* FMEO Declarations**************** */ 
+    char *name;			/*input raster name */
+
+    char *result;		/*output raster name */
+
+    
+	/*File Descriptors */ 
+    int infd_redchan, infd_nirchan, infd_greenchan;
+
+    int infd_bluechan, infd_chan5chan, infd_chan7chan;
+
+    int outfd;
+
+    char *bluechan, *greenchan, *redchan, *nirchan, *chan5chan, *chan7chan;
+
+    int i = 0, j = 0;
+
+    void *inrast_redchan, *inrast_nirchan, *inrast_greenchan;
+
+    void *inrast_bluechan, *inrast_chan5chan, *inrast_chan7chan;
+
+    DCELL * outrast;
+    RASTER_MAP_TYPE data_type_output = DCELL_TYPE;
+    RASTER_MAP_TYPE data_type_redchan;
+    RASTER_MAP_TYPE data_type_nirchan;
+    RASTER_MAP_TYPE data_type_greenchan;
+    RASTER_MAP_TYPE data_type_bluechan;
+    RASTER_MAP_TYPE data_type_chan5chan;
+    RASTER_MAP_TYPE data_type_chan7chan;
+    
+
+	/************************************/ 
+	G_gisinit(argv[0]);
+    module = G_define_module();
+    module->keywords = _("vegetation index, biophysical parameters");
+    module->description =
+	_("14 types of vegetation indices from red and nir, and only some requiring additional bands");
+    
+	/* Define the different options */ 
+	input1 = G_define_option();
+    input1->key = _("viname");
+    input1->type = TYPE_STRING;
+    input1->required = YES;
+    input1->gisprompt = _("Name of VI");
+    input1->description =
+	_("Name of VI: sr,ndvi,ipvi,dvi,evi,pvi,wdvi,savi,msavi,msavi2,gemi,arvi,gvi,gari.");
+    input1->answer = _("ndvi");
+    input2 = G_define_standard_option(G_OPT_R_INPUT);
+    input2->key = _("red");
+    input2->description =
+	_("Name of the RED Channel surface reflectance map [0.0;1.0]");
+    input3 = G_define_standard_option(G_OPT_R_INPUT);
+    input3->key = _("nir");
+    input3->description =
+	_("Name of the NIR Channel surface reflectance map [0.0;1.0]");
+    input4 = G_define_standard_option(G_OPT_R_INPUT);
+    input4->key = _("green");
+    input4->required = NO;
+    input4->description =
+	_("Name of the GREEN Channel surface reflectance map [0.0;1.0]");
+    input5 = G_define_standard_option(G_OPT_R_INPUT);
+    input5->key = _("blue");
+    input5->required = NO;
+    input5->description =
+	_("Name of the BLUE Channel surface reflectance map [0.0;1.0]");
+    input6 = G_define_standard_option(G_OPT_R_INPUT);
+    input6->key = _("chan5");
+    input6->required = NO;
+    input6->description =
+	_("Name of the CHAN5 Channel surface reflectance map [0.0;1.0]");
+    input7 = G_define_standard_option(G_OPT_R_INPUT);
+    input7->key = _("chan7");
+    input7->required = NO;
+    input7->description =
+	_("Name of the CHAN7 Channel surface reflectance map [0.0;1.0]");
+    output = G_define_standard_option(G_OPT_R_OUTPUT);
+    output->description = _("Name of the output vi layer");
+    
+
+	/********************/ 
+	if (G_parser(argc, argv))
+	exit(EXIT_FAILURE);
+    viflag = input1->answer;
+    redchan = input2->answer;
+    nirchan = input3->answer;
+    greenchan = input4->answer;
+    bluechan = input5->answer;
+    chan5chan = input6->answer;
+    chan7chan = input7->answer;
+    result = output->answer;
+    
+
+	/***************************************************/ 
+	mapset = G_find_cell2(redchan, "");
+    if (mapset == NULL) {
+	G_fatal_error(_("%s - cell file [%s] not found"),
+			G_program_name(), redchan);
+    }
+    data_type_redchan = G_raster_map_type(redchan, mapset);
+    if ((infd_redchan = G_open_cell_old(redchan, mapset)) < 0){
+	G_fatal_error(_("%s - Cannot open cell file [%s]"),
+			G_program_name(), redchan);
+    }
+    if (G_get_cellhd(redchan, mapset, &cellhd) < 0){
+	G_fatal_error(_("%s - Cannot read file header of [%s])"),
+			G_program_name(), redchan);
+    }
+    inrast_redchan = G_allocate_raster_buf(data_type_redchan);
+    
+
+	/***************************************************/ 
+	mapset = G_find_cell2(nirchan, "");
+    if (mapset == NULL) {
+	G_fatal_error(_("%s - cell file [%s] not found"),
+			G_program_name(), nirchan);
+    }
+    data_type_nirchan = G_raster_map_type(nirchan, mapset);
+    if ((infd_nirchan = G_open_cell_old(nirchan, mapset)) < 0){
+	G_fatal_error(_("%s - Cannot open cell file [%s]"),
+			G_program_name(), nirchan);
+    }
+    if (G_get_cellhd(nirchan, mapset, &cellhd) < 0){
+	G_fatal_error(_("%s - Cannot read file header of [%s]"),
+			G_program_name(), nirchan);
+    }
+    inrast_nirchan = G_allocate_raster_buf(data_type_nirchan);
+    
+
+	/***************************************************/ 
+	if (greenchan) {
+	mapset = G_find_cell2(greenchan, "");
+	if (mapset == NULL) {
+	    G_fatal_error(_("%s - cell file [%s] not found"),
+			G_program_name(), greenchan);
+	}
+	data_type_greenchan = G_raster_map_type(greenchan, mapset);
+	if ((infd_greenchan = G_open_cell_old(greenchan, mapset)) < 0){
+	    G_fatal_error(_("%s - Cannot open cell file [%s]"),
+			G_program_name(), greenchan);
+        }
+	if (G_get_cellhd(greenchan, mapset, &cellhd) < 0){
+	    G_fatal_error(_("%s - Cannot read file header of [%s])"),
+			G_program_name(), greenchan);
+        }
+	inrast_greenchan = G_allocate_raster_buf(data_type_greenchan);
+    }
+    
+
+	/***************************************************/ 
+	if (bluechan) {
+	mapset = G_find_cell2(bluechan, "");
+	if (mapset == NULL) {
+	    G_fatal_error(_("%s - cell file [%s] not found"),
+			G_program_name(), bluechan);
+	}
+	data_type_bluechan = G_raster_map_type(bluechan, mapset);
+	if ((infd_bluechan = G_open_cell_old(bluechan, mapset)) < 0){
+	    G_fatal_error(_("%s - Cannot open cell file [%s]"),
+			G_program_name(), bluechan);
+        }
+	if (G_get_cellhd(bluechan, mapset, &cellhd) < 0){
+	    G_fatal_error(_("%s - Cannot read file header of [%s])"),
+			G_program_name(), bluechan);
+        }
+	inrast_bluechan = G_allocate_raster_buf(data_type_bluechan);
+    }
+    
+
+	/***************************************************/ 
+	if (chan5chan) {
+	mapset = G_find_cell2(chan5chan, "");
+	if (mapset == NULL) {
+	    G_fatal_error(_("%s - cell file [%s] not found"),
+			G_program_name(), chan5chan);
+	}
+	data_type_chan5chan = G_raster_map_type(chan5chan, mapset);
+	if ((infd_chan5chan = G_open_cell_old(chan5chan, mapset)) < 0){
+	    G_fatal_error(_("%s - Cannot open cell file [%s]"),
+			G_program_name(), chan5chan);
+        }
+	if (G_get_cellhd(chan5chan, mapset, &cellhd) < 0){
+	    G_fatal_error(_("%s - Cannot read file header of [%s])"),
+			G_program_name(), chan5chan);
+        }
+	inrast_chan5chan = G_allocate_raster_buf(data_type_chan5chan);
+    }
+    
+
+	/***************************************************/ 
+	if (chan7chan) {
+	mapset = G_find_cell2(chan7chan, "");
+	if (mapset == NULL) {
+	    G_fatal_error(_("%s - cell file [%s] not found"),
+			G_program_name(), chan7chan);
+	}
+	data_type_chan7chan = G_raster_map_type(chan7chan, mapset);
+	if ((infd_chan7chan = G_open_cell_old(chan7chan, mapset)) < 0){
+	    G_fatal_error(_("%s - Cannot open cell file [%s]"),
+			G_program_name(), chan7chan);
+        }
+	if (G_get_cellhd(chan7chan, mapset, &cellhd) < 0){
+	    G_fatal_error(_("%s - Cannot read file header of [%s])"),
+			G_program_name(), chan7chan);
+        }
+	inrast_chan7chan = G_allocate_raster_buf(data_type_chan7chan);
+    }
+    
+
+	/***************************************************/ 
+	G_debug(3, "number of rows %d", cellhd.rows);
+    nrows = G_window_rows();
+    ncols = G_window_cols();
+    outrast = G_allocate_raster_buf(data_type_output);
+    
+	/* Create New raster files */ 
+	if ((outfd = G_open_raster_new(result, data_type_output)) < 0){
+	G_fatal_error(_("%s - Could not open <%s>"),
+			G_program_name(), result);
+        }
+    
+	/* Process pixels */ 
+	for (row = 0; row < nrows; row++)
+	 {
+	DCELL d;
+	DCELL d_bluechan;
+	DCELL d_greenchan;
+	DCELL d_redchan;
+	DCELL d_nirchan;
+	DCELL d_chan5chan;
+	DCELL d_chan7chan;
+	G_percent(row, nrows, 2);
+	if (G_get_raster_row
+	     (infd_redchan, inrast_redchan, row, data_type_redchan) < 0){
+	    G_fatal_error(_("%s - Could not read from <%s>"),
+			G_program_name(), redchan);
+        }
+	if (G_get_raster_row
+	     (infd_nirchan, inrast_nirchan, row, data_type_nirchan) < 0){
+	    G_fatal_error(_("%s - Could not read from <%s>"),
+			G_program_name(), nirchan);
+        }
+	if (greenchan) {
+	    if (G_get_raster_row
+		 (infd_greenchan, inrast_greenchan, row,
+		  data_type_greenchan) < 0){
+		G_fatal_error(_("%s - Could not read from <%s>"),
+			G_program_name(), greenchan);
+            }
+	}
+	if (bluechan) {
+	    if (G_get_raster_row
+		 (infd_bluechan, inrast_bluechan, row,
+		  data_type_bluechan) < 0){
+		G_fatal_error(_("%s - Could not read from <%s>"),
+			G_program_name(), bluechan);
+            }
+	}
+	if (chan5chan) {
+	    if (G_get_raster_row
+		 (infd_chan5chan, inrast_chan5chan, row,
+		  data_type_chan5chan) < 0){
+		G_fatal_error(_("%s - Could not read from <%s>"),
+			G_program_name(), chan5chan);
+            }
+	}
+	if (chan7chan) {
+	    if (G_get_raster_row
+		 (infd_chan7chan, inrast_chan7chan, row,
+		  data_type_chan7chan) < 0){
+		G_fatal_error(_("%s - Could not read from <%s>"),
+			G_program_name(), chan7chan);
+            }
+	}
+	
+	    /*process the data */ 
+	    for (col = 0; col < ncols; col++)
+	     {
+	    switch (data_type_redchan) {
+	    case CELL_TYPE:
+		d_redchan = (double)((CELL *) inrast_redchan)[col];
+		break;
+	    case FCELL_TYPE:
+		d_redchan = (double)((FCELL *) inrast_redchan)[col];
+		break;
+	    case DCELL_TYPE:
+		d_redchan = ((DCELL *) inrast_redchan)[col];
+		break;
+	    }
+	    switch (data_type_nirchan) {
+	    case CELL_TYPE:
+		d_nirchan = (double)((CELL *) inrast_nirchan)[col];
+		break;
+	    case FCELL_TYPE:
+		d_nirchan = (double)((FCELL *) inrast_nirchan)[col];
+		break;
+	    case DCELL_TYPE:
+		d_nirchan = ((DCELL *) inrast_nirchan)[col];
+		break;
+	    }
+	    if (greenchan) {
+		switch (data_type_greenchan) {
+		case CELL_TYPE:
+		    d_greenchan = (double)((CELL *) inrast_greenchan)[col];
+		    break;
+		case FCELL_TYPE:
+		    d_greenchan = (double)((FCELL *) inrast_greenchan)[col];
+		    break;
+		case DCELL_TYPE:
+		    d_greenchan = ((DCELL *) inrast_greenchan)[col];
+		    break;
+		}
+	    }
+	    if (bluechan) {
+		switch (data_type_bluechan) {
+		case CELL_TYPE:
+		    d_bluechan = (double)((CELL *) inrast_bluechan)[col];
+		    break;
+		case FCELL_TYPE:
+		    d_bluechan = (double)((FCELL *) inrast_bluechan)[col];
+		    break;
+		case DCELL_TYPE:
+		    d_bluechan = ((DCELL *) inrast_bluechan)[col];
+		    break;
+		}
+	    }
+	    if (chan5chan) {
+		switch (data_type_chan5chan) {
+		case CELL_TYPE:
+		    d_chan5chan = (double)((CELL *) inrast_chan5chan)[col];
+		    break;
+		case FCELL_TYPE:
+		    d_chan5chan = (double)((FCELL *) inrast_chan5chan)[col];
+		    break;
+		case DCELL_TYPE:
+		    d_chan5chan = ((DCELL *) inrast_chan5chan)[col];
+		    break;
+		}
+	    }
+	    if (chan7chan) {
+		switch (data_type_chan7chan) {
+		case CELL_TYPE:
+		    d_chan7chan = (double)((CELL *) inrast_chan7chan)[col];
+		    break;
+		case FCELL_TYPE:
+		    d_chan7chan = (double)((FCELL *) inrast_chan7chan)[col];
+		    break;
+		case DCELL_TYPE:
+		    d_chan7chan = ((DCELL *) inrast_chan7chan)[col];
+		    break;
+		}
+	    }
+	    if (G_is_d_null_value(&d_redchan) ||
+		 G_is_d_null_value(&d_nirchan) || 
+                 ((greenchan) && G_is_d_null_value(&d_greenchan)) ||
+		 ((bluechan) && G_is_d_null_value(&d_bluechan)) ||
+		 ((chan5chan) && G_is_d_null_value(&d_chan5chan)) ||
+		 ((chan7chan) && G_is_d_null_value(&d_chan7chan))) {
+		G_set_d_null_value(&outrast[col], 1);
+	    }
+	    else {
+		
+
+		    /************************************/ 
+		    /*calculate simple_ratio        */ 
+		    if (!strcmp(viflag, "sr")) {
+		    d = s_r(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate ndvi                    */ 
+		    if (!strcmp(viflag, "ndvi")) {
+		    if (d_redchan + d_nirchan < 0.001) {
+			G_set_d_null_value(&outrast[col], 1);
+		    }
+		    else {
+			d = nd_vi(d_redchan, d_nirchan);
+			((DCELL *) outrast)[col] = d;
+		    }
+		}
+		
+		    /*calculate ipvi                    */ 
+		    if (!strcmp(viflag, "ipvi")) {
+		    d = ip_vi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate dvi             */ 
+		    if (!strcmp(viflag, "dvi")) {
+		    d = d_vi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate evi             */ 
+		    if (!strcmp(viflag, "evi")) {
+		    d = e_vi(d_bluechan, d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate pvi             */ 
+		    if (!strcmp(viflag, "pvi")) {
+		    d = p_vi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate wdvi                    */ 
+		    if (!strcmp(viflag, "wdvi")) {
+		    d = wd_vi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate savi                    */ 
+		    if (!strcmp(viflag, "savi")) {
+		    d = sa_vi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate msavi                   */ 
+		    if (!strcmp(viflag, "msavi")) {
+		    d = msa_vi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate msavi2            */ 
+		    if (!strcmp(viflag, "msavi2")) {
+		    d = msa_vi2(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate gemi                    */ 
+		    if (!strcmp(viflag, "gemi")) {
+		    d = ge_mi(d_redchan, d_nirchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate arvi                    */ 
+		    if (!strcmp(viflag, "arvi")) {
+		    d = ar_vi(d_redchan, d_nirchan, d_bluechan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate gvi            */ 
+		    if (!strcmp(viflag, "gvi")) {
+		    d = g_vi(d_bluechan, d_greenchan, d_redchan, d_nirchan,
+			      d_chan5chan, d_chan7chan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+		
+		    /*calculate gari                    */ 
+		    if (!strcmp(viflag, "gari")) {
+		    d = ga_ri(d_redchan, d_nirchan, d_bluechan, d_greenchan);
+		    ((DCELL *) outrast)[col] = d;
+		}
+	    }
+	    }
+	if (G_put_raster_row(outfd, outrast, data_type_output) < 0){
+	    G_fatal_error(_("%s - Cannot write to output raster file"), 
+			G_program_name());
+        }
+	}
+    G_free(inrast_redchan);
+    G_close_cell(infd_redchan);
+    G_free(inrast_nirchan);
+    G_close_cell(infd_nirchan);
+    if (greenchan) {
+	G_free(inrast_greenchan);
+	G_close_cell(infd_greenchan);
+    }
+    if (bluechan) {
+	G_free(inrast_bluechan);
+	G_close_cell(infd_bluechan);
+    }
+    if (chan5chan) {
+	G_free(inrast_chan5chan);
+	G_close_cell(infd_chan5chan);
+    }
+    if (chan7chan) {
+	G_free(inrast_chan7chan);
+	G_close_cell(infd_chan7chan);
+    }
+    G_free(outrast);
+    G_close_cell(outfd);
+    
+	/* Color from -1.0 to +1.0 in grey */ 
+	G_init_colors(&colors);
+    G_add_color_rule(-1.0, 0, 0, 0, 1.0, 255, 255, 255, &colors);
+    G_short_history(result, "raster", &history);
+    G_command_history(&history);
+    G_write_history(result, &history);
+    exit(EXIT_SUCCESS);
+}
+
+

imagery/i.vi/msavi.c

@@ -0,0 +1,31 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* MSAVI: Modified Soil Adjusted Vegetation Index       
+     *                                                      
+     *                       s(NIR-s*red-a)                 
+     *                MSAVI = ---------------------------   
+     *                        (a*NIR+red-a*s+X*(1+s*s))     
+     *      where a is the soil line intercept, s is the    
+     *      soil line slope, and X  is an adjustment factor 
+     *      which is set to minimize soil noise (0.08 in    
+     *      original papers).                               
+     */ 
+double msa_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result =
+	    (1 / 2) * (2 * (nirchan + 1) -
+		       sqrt((2 * nirchan + 1) * (2 * nirchan + 1)) -
+		       (8 * (nirchan - redchan)));
+    }
+    return result;
+}
+
+

imagery/i.vi/msavi2.c

@@ -0,0 +1,24 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* MSAVI2: second Modified Soil Adjusted Vegetation Index
+     *      MSAVI2 = (1/2)*(2(NIR+1)-sqrt((2*NIR+1)^2-8(NIR-red)))
+     */ 
+double msa_vi2(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result =
+	    (1 / 2) * (2 * (nirchan + 1) -
+		       sqrt((2 * nirchan + 1) * (2 * nirchan + 1)) -
+		       (8 * (nirchan - redchan)));
+    }
+    return result;
+}
+
+

imagery/i.vi/ndvi.c

@@ -0,0 +1,19 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* Normalized Difference Vegetation Index */ 
+double nd_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = (nirchan - redchan) / (nirchan + redchan);
+    }
+    return result;
+}
+
+

imagery/i.vi/pvi.c

@@ -0,0 +1,25 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+ 
+    /*
+       PVI: Perpendicular Vegetation Index
+       
+       PVI = sin(a)NIR-cos(a)red
+       for a  isovegetation lines (lines of equal vegetation) would all be parallel to the soil line therefore a=1
+       
+     */ 
+double p_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = (sin(1) * nirchan) / (cos(1) * redchan);
+    }
+    return result;
+}
+
+

imagery/i.vi/savi.c

@@ -0,0 +1,20 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* Soil Adjusted Vegetation Index */ 
+double sa_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result =
+	    ((1 + 0.5) * (nirchan - redchan)) / (nirchan + redchan + 0.5);
+    }
+    return result;
+}
+
+

imagery/i.vi/sr.c

@@ -0,0 +1,19 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* Simple Vegetation ratio */ 
+double s_r(double redchan, double nirchan) 
+{
+    double result;
+
+    if ((redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = (nirchan / redchan);
+    }
+    return result;
+}
+
+

imagery/i.vi/wdvi.c

@@ -0,0 +1,21 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+    /* Weighted Difference Vegetation Index */ 
+double wd_vi(double redchan, double nirchan) 
+{
+    double result;
+
+    double a = 1;		/*slope of soil line */
+
+    if ((nirchan + redchan) == 0.0) {
+	result = -1.0;
+    }
+    else {
+	result = (nirchan - a * redchan);
+    }
+    return result;
+}
+
+