New false color/color handling

Now RGB based instead of HSV based, this also includes a new RGBA compositing function which cleans up the code responsible false color significantly.

Color palettes have also been moved into 1 file instead of 2

Makefile

@@ -1,4 +1,4 @@
-CC = gcc
+CC = clang
 BIN = /usr/bin
 INCLUDES = -I.
 CFLAGS = -O3 -Wall $(INCLUDES)
@@ -7,7 +7,7 @@ OBJS = main.o image.o dsp.o filter.o reg.o fcolor.o
 aptdec:	$(OBJS)
 	$(CC) -o $@ $(OBJS) -lm -lsndfile -lpng
 
-main.o:	  main.c temppalette.h gvipalette.h offsets.h messages.h
+main.o:	  main.c colorpalette.h offsets.h messages.h
 dsp.o:	  dsp.c filtercoeff.h filter.h
 filter.o: filter.c filter.h
 image.o:  image.c satcal.h offsets.h messages.h

README.md

@@ -54,7 +54,7 @@ To uninstall
 -i [r|a|b|c|t|l]
 Output image type
 Raw (r), Channel A (a), Channel B (b), False Color (c), Temperature (t), Layered (l)
-Default: ab
+Default: "ab"
 
 -d <dir>
 Images destination directory (optional).
@@ -62,17 +62,17 @@ Default: Current directory
 
 -s [15|16|17|18|19]
 Satellite number
-For temperature and false color generation
-Default: 19
+For temperature calibration
+Default: "19"
 
 -e [c|t]
 Enhancements
 Contrast (c) or Crop Telemetry (t)
-Defaults: ct
+Defaults: "ct"
 
 -c <file>
 Use configuration file for false color generation.
-Default: Internal parameters
+Default: Internal defaults
 ```
 
 ## Output

temppalette.h → colorpalette.h

@@ -1,3 +1,34 @@
+unsigned char GviPalette[256*3] = {
+  "\230t\17\233x\22\236{\27\241\200\33\244\203\37\247\210#\252\214'\255\220"
+  ",\260\2240\264\2305\267\2358\272\240=\274\245A\300\251E\303\255I\306\262"
+  "M\311\266Q\314\272V\317\276Z\322\302^\325\306b\330\312g\334\317k\337\323"
+  "o\342\330s\344\333w\350\337{\352\344\200\356\350\203\361\354\207\364\360"
+  "\213\367\364\220\372\370\224\376\376\230\376\375\230\376\372\227\376\366"
+  "\224\376\362\222\376\357\220\376\352\216\376\347\213\376\343\211\376\340"
+  "\207\376\334\205\376\330\202\376\325\200\376\321\177\376\315|\376\312z\376"
+  "\306y\376\302v\376\277t\376\273q\376\267o\376\263m\376\260k\376\254h\376"
+  "\250f\376\245d\376\241b\376\235_\376\232^\376\226[\376\223Y\376\217W\376"
+  "\213U\376\207R\376\203Q\376\200N\376}L\376zJ\376vG\376rE\376nB\376k@\376"
+  "g>\376d<\376`:\376\\7\376X6\376T3\376Q0\376M/\376J-\376F*\376C(\376>%\376"
+  ";$\3767!\3763\37\3760\35\376,\32\376(\31\376$\26\376!\24\376\35\22\376\32"
+  "\20\376\26\15\376\22\13\376\16\11\376\12\6\376\7\4\376\0\0\373\2\0\366\3"
+  "\0\362\5\0\355\7\0\350\11\0\343\13\0\336\15\0\332\17\0\325\21\0\320\22\0"
+  "\313\24\0\307\26\0\303\27\0\275\32\0\270\33\0\264\35\0\257\37\0\253!\0\246"
+  "#\0\241%\0\234&\0\227)\0\223+\0\216,\0\212.\0\2050\0\2002\0}4\0w6\0s7\0n"
+  "9\0i;\0e>\0`?\0[A\0VC\0QE\0MG\0HH\0CK\0?M\0:N\0""5P\0""0R\0,S\0'V\0\"X\0"
+  "\36Z\0\31\\\0\23^\0\17_\0\12a\0\3b\0\6e\2\12i\5\17n\11\23r\14\30v\17\34{"
+  "\23\40\200\26$\203\31)\207\35.\215\40""1\221$6\225':\232*?\236.C\2431G\250"
+  "4K\2548O\260;U\265>Y\272A\\\276Eb\303Ie\307Lj\313On\320Ss\324Vw\331Y{\336"
+  "]\200\342`\203\347d\207\353g\213\357j\217\364n\223\371q\230\376t\222\375"
+  "{\207\374\205}\373\216r\371\230g\371\241\\\370\254Q\367\265F\365\300;\364"
+  "\3110\363\323%\362\334\32\361\347\17\357\361\3\356\371\4\353\370\3\347\365"
+  "\4\342\361\4\335\357\4\331\354\4\323\351\3\317\346\3\313\343\4\306\340\3"
+  "\301\335\3\275\332\3\270\327\3\263\324\2\257\322\3\252\316\3\245\314\3\241"
+  "\311\2\234\306\2\230\303\2\223\300\3\216\275\3\211\273\2\205\267\2\200\265"
+  "\2|\262\2w\257\2s\254\2n\251\2j\246\2e\243\2`\240\2[\235\2W\232\1S\230\2"
+  "M\225\1I\221\2E\217\1@\214\1;\211\1""7\206\1""1\203\1-\200\0(~\1${\0\37y"
+  "\0\33u\0\25r\0\21p\0\14l\0\7j\0\3"
+};
 unsigned char TempPalette[256*3] = {
   "\376\376\376\376\376\376\375\375\376\374\375\376\374\375\375\374\373\375"
   "\373\373\375\372\373\375\372\373\374\372\372\374\371\372\374\371\371\375"
@@ -38,5 +69,5 @@ unsigned char TempPalette[256*3] = {
   "\370J\352\370I\360\370G\367\371F\370\362E\371\354C\370\345A\371\336@\371"
   "\326?\372\316=\372\307;\372\277:\372\2679\373\2577\373\2475\373\2373\373"
   "\2261\373\2161\373\206.\373}-\374u,\375k*\374b(\375Y'\375O%\375E#\375;\""
-  "\3762\40\376(\37\376\35\35",
-};
+  "\3762\40\376(\37\376\35"
+};

falsecolor.conf

@@ -1,9 +1,10 @@
-30.0
-90.0
-100.0
-230 0.2 0.3
-230 0.0 1.0
-200.0 0.7 0.6
-240.0 0.6 0.4 
-60.0 0.6 0.2
-100.0 0.1 0.5
+28 44 95
+23 78 37 
+240 250 255
+50
+0.5
+24
+34
+14
+141
+114

fcolor.c

@@ -3,133 +3,89 @@
 #include "offsets.h"
 
 typedef struct {
-    float h, s, v;
-} hsvpix_t;
-
-static void HSVtoRGB(float *r, float *g, float *b, hsvpix_t pix) {
-    int i;
-    double f, p, q, t, h;
-
-    if (pix.s == 0) {
-        // achromatic (grey)
-        *r = *g = *b = pix.v;
-        return;
-    }
-
-    h = pix.h / 60;		// sector 0 to 5
-    i = floor(h);
-    f = h - i;			// factorial part of h
-    p = pix.v * (1 - pix.s);
-    q = pix.v * (1 - pix.s * f);
-    t = pix.v * (1 - pix.s * (1 - f));
-
-    switch (i) {
-        case 0:
-            *r = pix.v;
-            *g = t;
-            *b = p;
-            break;
-        case 1:
-            *r = q;
-            *g = pix.v;
-            *b = p;
-            break;
-        case 2:
-            *r = p;
-            *g = pix.v;
-            *b = t;
-            break;
-        case 3:
-            *r = p;
-            *g = q;
-            *b = pix.v;
-            break;
-        case 4:
-            *r = t;
-            *g = p;
-            *b = pix.v;
-            break;
-        default:			// case 5:
-            *r = pix.v;
-            *g = p;
-            *b = q;
-            break;
-    }
-
-}
+    float r, g, b, a;
+} rgba;
 
 static struct {
-    float Seathreshold;
-    float Landthreshold;
-    float Threshold;
-    hsvpix_t CloudTop;
-    hsvpix_t CloudBot;
-    hsvpix_t SeaTop;
-    hsvpix_t SeaBot;
-    hsvpix_t GroundTop;
-    hsvpix_t GroundBot;
+    rgba Sea;
+    rgba Land;
+    rgba Cloud;
+    int Seaintensity;
+    float Seaoffset;
+    int Landthreshold;
+    int Landintensity;
+    int Landoffset;
+    int Cloudthreshold;
+    int Cloudintensity;
 } fcinfo = {
-    30.0, 90.0, 155.0, {
-    230, 0.2, 0.3}, {
-    230, 0.0, 1.0}, {
-    200.0, 0.7, 0.6}, {
-    240.0, 0.6, 0.4}, {
-    60.0, 0.6, 0.2}, {
-    100.0, 0.0, 0.5}
+    {28,  44,  95, 1},
+    {23,  78,  37, 1},
+    {240, 250, 255, 1},
+    50,
+    0.5,
+    24,
+    34,
+    14,
+    141,
+    114
 };
 
-void readfconf(char *file) {
+// Read the config file
+void readfcconf(char *file) {
     FILE *fin;
 
     fin = fopen(file, "r");
     if (fin == NULL)
 	    return;
 
-    fscanf(fin, "%g\n", &fcinfo.Seathreshold);
-    fscanf(fin, "%g\n", &fcinfo.Landthreshold);
-    fscanf(fin, "%g\n", &fcinfo.Threshold);
-    fscanf(fin, "%g %g %g\n", &fcinfo.CloudTop.h,  &fcinfo.CloudTop.s,  &fcinfo.CloudTop.v);
-    fscanf(fin, "%g %g %g\n", &fcinfo.CloudBot.h,  &fcinfo.CloudBot.s,  &fcinfo.CloudBot.v);
-    fscanf(fin, "%g %g %g\n", &fcinfo.SeaTop.h,    &fcinfo.SeaTop.s,    &fcinfo.SeaTop.v);
-    fscanf(fin, "%g %g %g\n", &fcinfo.SeaBot.h,    &fcinfo.SeaBot.s,    &fcinfo.SeaBot.v);
-    fscanf(fin, "%g %g %g\n", &fcinfo.GroundTop.h, &fcinfo.GroundTop.s, &fcinfo.GroundTop.v);
-    fscanf(fin, "%g %g %g\n", &fcinfo.GroundBot.h, &fcinfo.GroundBot.s, &fcinfo.GroundBot.v);
+    fscanf(fin, "%g %g %g\n", &fcinfo.Sea.r,   &fcinfo.Sea.g,   &fcinfo.Sea.b);
+    fscanf(fin, "%g %g %g\n", &fcinfo.Land.r,  &fcinfo.Land.g,  &fcinfo.Land.b);
+    fscanf(fin, "%g %g %g\n", &fcinfo.Cloud.r, &fcinfo.Cloud.g, &fcinfo.Cloud.b);
+    fscanf(fin, "%d\n",       &fcinfo.Seaintensity);
+    fscanf(fin, "%g\n",       &fcinfo.Seaoffset);
+    fscanf(fin, "%d\n",       &fcinfo.Landthreshold);
+    fscanf(fin, "%d\n",       &fcinfo.Landintensity);
+    fscanf(fin, "%d\n",       &fcinfo.Landoffset);
+    fscanf(fin, "%d\n",       &fcinfo.Cloudthreshold);
+    fscanf(fin, "%d",         &fcinfo.Cloudintensity);
 
     fclose(fin);
 };
 
-void falsecolor(double v, double t, float *r, float *g, float *b) {
-    hsvpix_t top, bot, c;
-    double scv, sct;
-
-    if (t > fcinfo.Threshold) {
-        if (v < fcinfo.Seathreshold) {
-            // Sea
-            top = fcinfo.SeaTop, bot = fcinfo.SeaBot;
-            scv = v / fcinfo.Seathreshold;
-            sct = (256.0 - t) / (256.0 - fcinfo.Threshold);
-        } else {
-            // Ground
-            top = fcinfo.GroundTop, bot = fcinfo.GroundBot;
-            scv = (v - fcinfo.Seathreshold) / (fcinfo.Landthreshold - fcinfo.Seathreshold);
-            sct = (256.0 - t) / (256.0 - fcinfo.Threshold);
-        }
-    } else {
-        // Clouds
-        top = fcinfo.CloudTop, bot = fcinfo.CloudBot;
-        scv = v / 256.0;
-        sct = (256.0 - t) / 256.0;
-    }
+// RGBA Composite
+rgba composite(rgba top, rgba bottom){
+    rgba composite;
+	composite.r = MCOMPOSITE(top.r, top.a, bottom.r, bottom.a);
+	composite.g = MCOMPOSITE(top.g, top.a, bottom.g, bottom.a);
+	composite.b = MCOMPOSITE(top.b, top.a, bottom.b, bottom.a);
+    composite.a = bottom.a == 1 || top.a == 1 ? 1 : (top.a+bottom.a)/2;
+    return composite;
+}
 
-    c.s = top.s + sct * (bot.s - top.s);
-    c.v = top.v + scv * (bot.v - top.v);
-    c.h = top.h + scv * sct * (bot.h - top.h);
+void falsecolor(float vis, float temp, float *r, float *g, float *b){
+    rgba buffer;
+    fcinfo.Land.a = 0; fcinfo.Sea.a = 0;
 
-    HSVtoRGB(r, g, b, c);
-};
+    // Calculate intensity of sea and land
+    fcinfo.Sea.a  = CLIP(vis, 0, 20)/fcinfo.Seaintensity + fcinfo.Seaoffset;
+	if(vis > fcinfo.Landthreshold) fcinfo.Land.a = CLIP(vis-fcinfo.Landoffset, 0, fcinfo.Landintensity)/fcinfo.Landintensity;
+
+    // Composite land on top of sea
+	buffer = composite(fcinfo.Land, fcinfo.Sea);
+    buffer.a = 1;
+
+    // Composite clouds on top
+	fcinfo.Cloud.a = CLIP(temp-fcinfo.Cloudthreshold, 0, fcinfo.Cloudintensity)/fcinfo.Cloudintensity;
+	buffer = composite(fcinfo.Cloud, buffer);
 
+    *r = buffer.r;
+    *g = buffer.g;
+    *b = buffer.b;
+}
+
+// GVI (global vegetation index) false color
 void Ngvi(float **prow, int nrow) {
-    printf("GVI... ");
+    printf("Computing GVI false color\n");
     fflush(stdout);
 
     for (int n = 0; n < nrow; n++) {
@@ -148,6 +104,4 @@ void Ngvi(float **prow, int nrow) {
             pixelv[i + CHB_OFFSET] = pv;
         }
     }
-    printf("Done\n");
-};
-
+};

gvipalette.h

@@ -1,31 +0,0 @@
-unsigned char GviPalette[256*3] = {
-  "\230t\17\233x\22\236{\27\241\200\33\244\203\37\247\210#\252\214'\255\220"
-  ",\260\2240\264\2305\267\2358\272\240=\274\245A\300\251E\303\255I\306\262"
-  "M\311\266Q\314\272V\317\276Z\322\302^\325\306b\330\312g\334\317k\337\323"
-  "o\342\330s\344\333w\350\337{\352\344\200\356\350\203\361\354\207\364\360"
-  "\213\367\364\220\372\370\224\376\376\230\376\375\230\376\372\227\376\366"
-  "\224\376\362\222\376\357\220\376\352\216\376\347\213\376\343\211\376\340"
-  "\207\376\334\205\376\330\202\376\325\200\376\321\177\376\315|\376\312z\376"
-  "\306y\376\302v\376\277t\376\273q\376\267o\376\263m\376\260k\376\254h\376"
-  "\250f\376\245d\376\241b\376\235_\376\232^\376\226[\376\223Y\376\217W\376"
-  "\213U\376\207R\376\203Q\376\200N\376}L\376zJ\376vG\376rE\376nB\376k@\376"
-  "g>\376d<\376`:\376\\7\376X6\376T3\376Q0\376M/\376J-\376F*\376C(\376>%\376"
-  ";$\3767!\3763\37\3760\35\376,\32\376(\31\376$\26\376!\24\376\35\22\376\32"
-  "\20\376\26\15\376\22\13\376\16\11\376\12\6\376\7\4\376\0\0\373\2\0\366\3"
-  "\0\362\5\0\355\7\0\350\11\0\343\13\0\336\15\0\332\17\0\325\21\0\320\22\0"
-  "\313\24\0\307\26\0\303\27\0\275\32\0\270\33\0\264\35\0\257\37\0\253!\0\246"
-  "#\0\241%\0\234&\0\227)\0\223+\0\216,\0\212.\0\2050\0\2002\0}4\0w6\0s7\0n"
-  "9\0i;\0e>\0`?\0[A\0VC\0QE\0MG\0HH\0CK\0?M\0:N\0""5P\0""0R\0,S\0'V\0\"X\0"
-  "\36Z\0\31\\\0\23^\0\17_\0\12a\0\3b\0\6e\2\12i\5\17n\11\23r\14\30v\17\34{"
-  "\23\40\200\26$\203\31)\207\35.\215\40""1\221$6\225':\232*?\236.C\2431G\250"
-  "4K\2548O\260;U\265>Y\272A\\\276Eb\303Ie\307Lj\313On\320Ss\324Vw\331Y{\336"
-  "]\200\342`\203\347d\207\353g\213\357j\217\364n\223\371q\230\376t\222\375"
-  "{\207\374\205}\373\216r\371\230g\371\241\\\370\254Q\367\265F\365\300;\364"
-  "\3110\363\323%\362\334\32\361\347\17\357\361\3\356\371\4\353\370\3\347\365"
-  "\4\342\361\4\335\357\4\331\354\4\323\351\3\317\346\3\313\343\4\306\340\3"
-  "\301\335\3\275\332\3\270\327\3\263\324\2\257\322\3\252\316\3\245\314\3\241"
-  "\311\2\234\306\2\230\303\2\223\300\3\216\275\3\211\273\2\205\267\2\200\265"
-  "\2|\262\2w\257\2s\254\2n\251\2j\246\2e\243\2`\240\2[\235\2W\232\1S\230\2"
-  "M\225\1I\221\2E\217\1@\214\1;\211\1""7\206\1""1\203\1-\200\0(~\1${\0\37y"
-  "\0\33u\0\25r\0\21p\0\14l\0\7j\0\3g"
-};

main.c

@@ -27,14 +27,15 @@
 
 #include <libgen.h>
 
+#include <math.h>
+
 #include <sndfile.h>
 #include <png.h>
 
 #include "messages.h"
 #include "offsets.h"
 
-#include "temppalette.h"
-#include "gvipalette.h"
+#include "colorpalette.h"
 
 extern int getpixelrow(float *pixelv);
 extern int init_dsp(double F);;
@@ -74,7 +75,7 @@ static int initsnd(char *filename) {
 
 // Get a sample from the wave file
 int getsample(float *sample, int nb) {
-    return(sf_read_float(inwav, sample, nb));
+    return sf_read_float(inwav, sample, nb);
 }
 
 static png_text text_ptr[] = {
@@ -95,7 +96,7 @@ static int ImageOut(char *filename, char *chid, float **prow, int nrow, int widt
     png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
     if (!png_ptr) {
 		fprintf(stderr, ERR_PNG_WRITE);
-		return(1);
+		return(0);
     }
 
 	// Metadata
@@ -103,7 +104,7 @@ static int ImageOut(char *filename, char *chid, float **prow, int nrow, int widt
     if (!info_ptr) {
 		png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
 		fprintf(stderr, ERR_PNG_INFO);
-		return(1);
+		return(0);
     }
 
     if(palette == NULL) {
@@ -156,9 +157,9 @@ static int ImageOut(char *filename, char *chid, float **prow, int nrow, int widt
 			}
 
 			if(layered){
-				// Layered image, basically overlay highlights in channel B over channel A
-				float cloud = CLIP(pixelv[i+CHB_OFFSET]-141, 0, 255)/114*255;
-				pixel[i] = CLIP(pixelv[i+CHA_OFFSET] + cloud, 0, 255);
+				// Layered image, overlay highlights in channel B over channel A
+				float cloud = CLIP(pixelv[i+CHB_OFFSET]-141, 0, 255)/114;
+				pixel[i] = MCOMPOSITE(255, cloud, pixelv[i+CHA_OFFSET], 1);
 			}else{
 				pixel[i] = pixelv[i + offset + f];
 			}
@@ -170,7 +171,7 @@ static int ImageOut(char *filename, char *chid, float **prow, int nrow, int widt
     fclose(pngfile);
     printf("\nDone\n");
     png_destroy_write_struct(&png_ptr, &info_ptr);
-    return(0);
+    return(1);
 }
 
 static int ImageRGBOut(char *filename, float **prow, int nrow) {
@@ -178,7 +179,7 @@ static int ImageRGBOut(char *filename, float **prow, int nrow) {
     png_infop info_ptr;
     png_structp png_ptr;
 
-    extern void falsecolor(double v, double t, float *r, float *g, float *b);
+    extern void falsecolor(float vis, float temp, float *r, float *g, float *b);
 
 	// Initalise the PNG writer
     png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
@@ -204,7 +205,7 @@ static int ImageRGBOut(char *filename, float **prow, int nrow) {
     text_ptr[1].text_length = strlen(text_ptr[1].text);
     png_set_text(png_ptr, info_ptr, text_ptr, 3);
 
-    printf("Computing false color & writing: %s... ", filename);
+    printf("Computing false color & writing: %s", filename);
     fflush(stdout);
     pngfile = fopen(filename, "wb");
     if (pngfile == NULL) {
@@ -221,23 +222,20 @@ static int ImageRGBOut(char *filename, float **prow, int nrow) {
 		pixelc = prow[n];
 
 		for (int i = 0; i < CH_WIDTH - 1; i++) {
-			float v, t;
-			float r, g, b;
-
-			v = pixelc[i+CHA_OFFSET];
-			t = pixelc[i+CHB_OFFSET];
+			float r = 0, g = 0, b = 0;
 
-			falsecolor(v, t, &r, &g, &b);
+			// False color computation
+			falsecolor(pixelc[i+CHA_OFFSET], pixelc[i+CHB_OFFSET], &r, &g, &b);
 
-			pix[i].red = 255.0 * r; 
-			pix[i].green = 255.0 * g;
-			pix[i].blue = 255.0 * b;
+			pix[i].red = r;
+			pix[i].green = g;
+			pix[i].blue = b;
 		}
 		png_write_row(png_ptr, (png_bytep) pix);
     }
     png_write_end(png_ptr, info_ptr);
     fclose(pngfile);
-    printf("Done\n");
+    printf("\nDone\n");
     png_destroy_write_struct(&png_ptr, &info_ptr);
     return(0);
 }
@@ -281,7 +279,7 @@ static void Distrib(char *filename, float **prow, int nrow) {
 extern int calibrate(float **prow, int nrow, int offset, int contrastBoost);
 extern void Temperature(float **prow, int nrow, int ch, int offset);
 extern int Ngvi(float **prow, int nrow);
-extern void readfconf(char *file);
+extern void readfcconf(char *file);
 extern int optind;
 extern char *optarg;
 
@@ -343,7 +341,7 @@ int main(int argc, char **argv) {
 				break;
 			// False color config file
 			case 'c':
-				readfconf(optarg);
+				readfcconf(optarg);
 				break;
 			// Output image type
 			case 'i':
@@ -366,7 +364,6 @@ int main(int argc, char **argv) {
 				usage();
 		}
     }
-
 	if(optind == argc){
 		printf("No audio files provided.\n");
 		usage();
@@ -419,7 +416,7 @@ int main(int argc, char **argv) {
 		sf_close(inwav);
 
 		// Layered images require contrast enhancements
-		int contrastBoost = CONTAINS(enchancements, 'c') || CONTAINS(imgopt, 'l');
+		int contrastBoost = CONTAINS(enchancements, 'c') || CONTAINS(imgopt, 'l') || CONTAINS(imgopt, 'c');
 
 		chA = calibrate(prow, nrow, CHA_OFFSET, 0);
 		chB = calibrate(prow, nrow, CHB_OFFSET, 0);
@@ -433,8 +430,8 @@ int main(int argc, char **argv) {
 			ImageOut(pngfilename, "Temperature", prow, nrow, CH_WIDTH, CHB_OFFSET, (png_color*)TempPalette, 0, 0);
 		}
 
-		// We have to run the contrast enhance here because the temperature function requires real data
-		// Yes, this is bodgy, yes I should replace this with something more elegant
+		// We have to run the contrast enhance here because the temperature calibration requires real data
+		// Yes, this requires running a large chunk of code again, but this will be addressed in the future
 		chA = calibrate(prow, nrow, CHA_OFFSET, contrastBoost);
 		chB = calibrate(prow, nrow, CHB_OFFSET, contrastBoost);
 
@@ -480,10 +477,10 @@ int main(int argc, char **argv) {
 
 		// False color image
 		if(CONTAINS(imgopt, 'c')){
-			if (chA == 2 && chB == 4) { // Normal false color
+			if (chA == 2 && chB >= 4) { // Normal false color
 				sprintf(pngfilename, "%s/%s-c.png", pngdirname, name);
 				ImageRGBOut(pngfilename, prow, nrow);
-			} else if (chA == 1 && chB == 2) { // GVI false color
+			} else if (chA == 1 && chB == 2) { // GVI (global vegetation index) false color
 				Ngvi(prow, nrow);
 				sprintf(pngfilename, "%s/%s-c.png", pngdirname, name);
 				ImageOut(pngfilename, "GVI False Color", prow, nrow, CH_WIDTH, CHB_OFFSET, (png_color*)GviPalette, 0, 0);

offsets.h

@@ -9,4 +9,5 @@
 #define TOTAL_TELE (SYNC_WIDTH+SPC_WIDTH+TELE_WIDTH+SYNC_WIDTH+SPC_WIDTH+TELE_WIDTH)
 
 #define CLIP(val, bottom, top) (val > top ? top : (val > bottom ? val : bottom))
-#define CONTAINS(str, char) (strchr(str, (int) char) != NULL)
+#define CONTAINS(str, char) (strchr(str, (int) char) != NULL)
+#define MCOMPOSITE(m1, a1, m2, a2) (m1*a1 + m2*a2*(1-a1))