Add gamma adjustment, improve MCIR colors

README.md

@@ -70,6 +70,7 @@ Apply a falsecolor palette
 -m <path>        Path to WXtoImg map
 -p <path>        Path to palette
 -r               Realtime decode
+-g               Gamma adjustment (1.0 = off)
 ```
 
 ### Image types

common.h

@@ -46,6 +46,7 @@ typedef struct {
 	int   realtime; // Realtime decoding
 	char *filename; // Output filename
 	char *palette; // Filename of palette
+	float gamma; // Gamma
 } options_t;
 
 enum imagetypes {

image.c

@@ -241,7 +241,7 @@ int calibrate(float **prow, int nrow, int offset, int width) {
 
 }
 
-void distrib(options_t *opts, image_t *img, char *chid) {
+void distrib(options_t *opts, image_t *img, char chid) {
 	int max = 0;
 
 	// Options
@@ -276,7 +276,7 @@ void distrib(options_t *opts, image_t *img, char *chid) {
 		for(int y = 0; y < 256; y++)
 			distrib.prow[y][x] = distrib.prow[y][x] / max * 255.0;
 
-	extern int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, char *chid, char *palette);
+	extern int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, char chid, char *palette);
 	ImageOut(&options, &distrib, 0, 256, "Distribution", chid, NULL);
 }
 

main.c

@@ -36,7 +36,7 @@ extern int getpixelrow(float *pixelv, int nrow, int *zenith, int reset);
 
 // I/O
 extern int readRawImage(char *filename, float **prow, int *nrow);
-extern int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, char *chid, char *palette);
+extern int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, char chid, char *palette);
 extern int initWriter(options_t *opts, image_t *img, int width, int height, char *desc, char *chid);
 extern void pushRow(float *row, int width);
 extern void closeWriter();
@@ -47,7 +47,7 @@ extern void histogramEqualise(float **prow, int nrow, int offset, int width);
 extern void linearEnhance(float **prow, int nrow, int offset, int width);
 extern void temperature(options_t *opts, image_t *img, int offset, int width);
 extern void denoise(float **prow, int nrow, int offset, int width);
-extern void distrib(options_t *opts, image_t *img, char *chid);
+extern void distrib(options_t *opts, image_t *img, char chid);
 extern void flipImage(image_t *img, int width, int offset);
 
 // Palettes
@@ -74,11 +74,11 @@ int main(int argc, char **argv) {
 		usage();
 	}
 
-	options_t opts = { "r", "", 19, "", ".", 0, "" };
+	options_t opts = { "r", "", 19, "", ".", 0, "", "", 1.0 };
 
 	// Parse arguments
 	int opt;
-	while ((opt = getopt(argc, argv, "o:m:d:i:s:e:rp:")) != EOF) {
+	while ((opt = getopt(argc, argv, "o:m:d:i:s:e:p:g:r")) != EOF) {
 		switch (opt) {
 			case 'd':
 				opts.path = optarg;
@@ -108,6 +108,9 @@ int main(int argc, char **argv) {
 			case 'p':
 				opts.palette = optarg;
 				break;
+			case 'g':
+				opts.gamma = atof(optarg);
+				break;
 			default:
 				usage();
 		}
@@ -296,7 +299,7 @@ static int initsnd(char *filename) {
 	return 1;
 }
 
-// Read samples from the wave file
+// Read samples from the audio file
 int getsample(float *sample, int nb) {
 	if(channels == 1){
 		return sf_read_float(audioFile, sample, nb);
@@ -335,6 +338,7 @@ static void usage(void) {
 	" -m <path>        Map file\n"
     " -p <path>        Path to palette\n"
 	" -r               Realtime decode\n"
+	" -g               Gamma adjustment (1.0 = off)\n"
 	"\nRefer to the README for more infomation\n");
 
 	exit(EINVAL);

pngio.c

@@ -100,12 +100,12 @@ int mapOverlay(char *filename, rgb_t **crow, int nrow, int zenith, int MCIR) {
 			if(MCIR){
 				if(map.b < 128 && map.g > 128){
 					// Land
-					float green = CLIP((map.g-256)/32.0, 0, 1);
-					float blue = 1 - CLIP((map.b-32)/64.0, 0, 1);
-					crow[y][cha] = (rgb_t){blue*127, 30+green*80, 40};
+					float green = CLIP(map.g/300, 0, 1);
+					float blue = 0.15 - CLIP(map.b/960.0, 0, 1);
+					crow[y][cha] = (rgb_t){blue*1000, green*98, blue*500.0};
 				}else{
 					// Sea
-					crow[y][cha] = (rgb_t){12, 30, 85};
+					crow[y][cha] = (rgb_t){9, 17, 74};
 				}
 			}
 
@@ -125,7 +125,7 @@ int mapOverlay(char *filename, rgb_t **crow, int nrow, int zenith, int MCIR) {
 
 			// Cloud overlay on channel A
 			if(MCIR){
-				float cloud = CLIP((crow[y][chb].r - 115) / 107, 0, 1);
+				float cloud = CLIP((crow[y][chb].r - 105) / 150, 0, 1);
 				crow[y][cha] = RGBcomposite((rgb_t){240, 250, 255}, cloud, crow[y][cha], 1);
 			}
 		}
@@ -409,6 +409,11 @@ int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, c
 
 	printf("Writing %s", outName);
 
+	
+	// Float power macro (for gamma adjustment)
+	#define POWF(a, b) (b == 1.0 ? a : exp(b * log(a)))
+	float a = POWF(255, opts->gamma)/255;
+
 	// Build image
 	for (int y = 0; y < img->nrow; y++) {
 		png_color pix[width]; // Color
@@ -416,17 +421,16 @@ int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, c
 
 		int skip = 0;
 		for (int x = 0; x < width; x++) {
-			if(crop_telemetry && x == CH_WIDTH){
+			if(crop_telemetry && x == CH_WIDTH)
 				skip += TELE_WIDTH + SYNC_WIDTH + SPC_WIDTH;
-			}
 
 			if(greyscale){
-				mpix[x] = img->prow[y][x + skip + offset];
+				mpix[x] = POWF(img->prow[y][x + skip + offset], opts->gamma)/a;
 			}else{
 				pix[x] = (png_color){
-					crow[y][x + skip + offset].r,
-					crow[y][x + skip + offset].g,
-					crow[y][x + skip + offset].b
+					POWF(crow[y][x + skip + offset].r, opts->gamma)/a,
+					POWF(crow[y][x + skip + offset].g, opts->gamma)/a,
+					POWF(crow[y][x + skip + offset].b, opts->gamma)/a
 				};
 			}
 		}