From 05e9507e1468ba0dce3efd448f7227aef8b49eff Mon Sep 17 00:00:00 2001
From: Thierry Leconte <f4dwv@users.sourceforge.net>
Date: Wed, 24 Aug 2005 20:30:36 +0000
Subject: [PATCH] add gvi colormap

---
 Makefile |  2 +-
 fcolor.c | 20 +++++++++++---------
 main.c   | 16 ++++++++++------
 3 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/Makefile b/Makefile
index 7ca4165..93d2631 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ OBJS= main.o image.o dsp.o filter.o reg.o fcolor.o
 atpdec:	$(OBJS)
 	$(CC) -o $@ $(OBJS) -lm -lsndfile -lpng
 
-main.o:	main.c version.h temppalette.h offsets.h
+main.o:	main.c version.h temppalette.h gvipalette.h offsets.h
 dsp.o:	dsp.c filtercoeff.h filter.h
 filter.o: filter.c filter.h
 image.o: image.c satcal.h offsets.h
diff --git a/fcolor.c b/fcolor.c
index f36bb22..a225017 100644
--- a/fcolor.c
+++ b/fcolor.c
@@ -70,7 +70,7 @@ static struct {
     hsvpix_t GroundTop;
     hsvpix_t GroundBot;
 } fcinfo = {
-    30.0, 90.0, 100.0, {
+    30.0, 90.0, 155.0, {
     230, 0.2, 0.3}, {
     230, 0.0, 1.0}, {
     200.0, 0.7, 0.6}, {
@@ -112,25 +112,25 @@ void falsecolor(double v, double t, float *r, float *g, float *b)
     hsvpix_t top, bot, c;
     double scv, sct;
 
-    if (t < fcinfo.Tthresold) {
+    if (t > fcinfo.Tthresold) {
 	if (v < fcinfo.Seathresold) {
 	    /* sea */
 	    top = fcinfo.SeaTop, bot = fcinfo.SeaBot;
 	    scv = v / fcinfo.Seathresold;
-	    sct = t / fcinfo.Tthresold;
+	    sct = (256.0-t) / (256.0-fcinfo.Tthresold);
 	} else {
 	    /* ground */
 	    top = fcinfo.GroundTop, bot = fcinfo.GroundBot;
 	    scv =
 		(v - fcinfo.Seathresold) / (fcinfo.Landthresold -
 					    fcinfo.Seathresold);
-	    sct = t / fcinfo.Tthresold;
+	    sct = (256.0-t) / (256.0-fcinfo.Tthresold);
 	}
     } else {
 	/* clouds */
 	top = fcinfo.CloudTop, bot = fcinfo.CloudBot;
-	scv = v / 255.0;
-	sct = t / 255.0;
+	scv = v / 256.0;
+	sct = (256.0-t) / 256.0;
     }
 
     c.s = top.s + sct * (bot.s - top.s);
@@ -140,11 +140,11 @@ void falsecolor(double v, double t, float *r, float *g, float *b)
     HSVtoRGB(r, g, b, c);
 };
 
-void Ngiv(float **prow, int nrow)
+void Ngvi(float **prow, int nrow)
 {
     int n;
 
-    printf("Vegetation ... ");
+    printf("GVI ... ");
     fflush(stdout);
 
     for (n = 0; n < nrow; n++) {
@@ -154,9 +154,11 @@ void Ngiv(float **prow, int nrow)
         pixelv = prow[n];
         for (i = 0; i < CH_WIDTH; i++) {
             float pv;
+	    double gvi;
 
-            pv = (pixelv[i + CHA_OFFSET]-pixelv[i + CHB_OFFSET])/(pixelv[i + CHA_OFFSET]+pixelv[i + CHB_OFFSET])*128.0+128.0;
+            gvi = (pixelv[i + CHA_OFFSET]-pixelv[i + CHB_OFFSET])/(pixelv[i + CHA_OFFSET]+pixelv[i + CHB_OFFSET]);
 
+            pv = (gvi+0.1)*340.0;
             if (pv > 255.0)
                 pv = 255.0;
             if (pv < 0.0)
diff --git a/main.c b/main.c
index 53532df..98434fa 100644
--- a/main.c
+++ b/main.c
@@ -22,19 +22,23 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+
 #ifdef WIN32
 #include "w32util.h"
 #else
 #include <libgen.h>
 #endif
-#include <string.h>
+
 #include <sndfile.h>
 #include <png.h>
 
 #include "version.h"
-#include "temppalette.h"
 #include "offsets.h"
 
+#include "temppalette.h"
+#include "gvipalette.h"
+
 extern int getpixelrow(float *pixelv);
 extern int init_dsp(double F);;
 
@@ -271,7 +275,7 @@ fclose(df);
 
 extern int Calibrate(float **prow, int nrow, int offset);
 extern void Temperature(float **prow, int nrow, int ch, int offset);
-extern int Ngiv(float **prow, int nrow);
+extern int Ngvi(float **prow, int nrow);
 extern void readfconf(char *file);
 extern int optind, opterr;
 extern char *optarg;
@@ -408,11 +412,11 @@ int main(int argc, char **argv)
 	    ImageRGBOut(pngfilename, prow, nrow);
 	}
 
-/* vegetation image */
+/* GVI image */
 	if (chA==1 && chB==2 && strchr(imgopt, (int) 'c') != NULL) {
-	    Ngiv(prow, nrow);
+	    Ngvi(prow, nrow);
 	    sprintf(pngfilename, "%s/%s-c.png", pngdirname, name);
-	   ImageOut(pngfilename, "Vegetation", prow, nrow, CH_WIDTH, CHB_OFFSET, (png_color*)TempPalette);
+	   ImageOut(pngfilename, "GVI", prow, nrow, CH_WIDTH, CHB_OFFSET, (png_color*)GviPalette);
 	}
     }
     exit(0);