Add palette support, remove falsecolor image type

I will tidy this up in the next few commits

.gitignore

@@ -43,8 +43,9 @@
 # Program specifics
 *.png
 !textlogo.png
+!palettes/*
 *.wav
 aptdec
 
 # VSCode
-.vscode
+.vscode

Makefile

@@ -1,7 +1,7 @@
 CC = gcc
 BIN = /usr/bin
 INCLUDES = -I.
-CFLAGS = -O3 -DNDEBUG -Wall -Wextra $(INCLUDES)
+CFLAGS = -O3 -g -Wall -Wextra $(INCLUDES)
 OBJS = main.o image.o dsp.o filter.o reg.o pngio.o median.o color.o
 
 aptdec:	$(OBJS)

README.md

@@ -15,7 +15,7 @@ For each audio file up to 6 images can be generated:
 2. Calibrated channel A image
 3. Calibrated channel B image
 4. Temperature compensated IR image
-5. False color image
+5. Palleted image
 6. MCIR (Map Color InfraRed) image
 
 The input audio file must be mono with a sample rate in the range of 4160-62400 Hz, lower samples rates will process faster.
@@ -51,9 +51,9 @@ To uninstall
 ## Options
 
 ```
--i [r|a|b|c|t|m]
+-i [r|a|b|t|m|p]
 Output image type
-Raw (r), Channel A (a), Channel B (b), False Color (c), Temperature (t) or MCIR (m)
+Raw (r), Channel A (a), Channel B (b), Palleted (p), Temperature (t) or MCIR (m)
 Default: "ab"
 
 -d <dir>
@@ -88,18 +88,18 @@ Image names are `audiofile-x.png`, where `x` is:
 
  - `r` for raw images
  - Sensor ID (`1`, `2`, `3A`, `3B`, `4`, `5`) for channel A|B images
- - `c` for false color
+ - `p` for a paletted image
  - `t` for temperature calibrated images
  - `m` for MCIR images
 
 Currently there are 6 available effects:
 
  - `t` for crop telemetry, off by default, only has effects on raw images
- - `h` for histogram equalise, stretch the colors in the image to black and white
+ - `h` for histogram equalise
  - `d` for a median denoise filter
  - `p` for a precipitation overlay
  - `f` to flip the image (for southbound passes)
- - `l` to linearly equalise the image (recommended for falsecolor images)
+ - `l` to linearly equalise the image, stretch the colors in the image to black and white
 
 ## Examples
 
@@ -111,6 +111,10 @@ This will process all `.wav` files in the current directory, generate calibrated
 
 Decode `audio.wav` with denoise and histogram equalization and save it into the current directory.
 
+`aptdec -e d -p palettes/N19-June-High-Vegetation.png -i p audio.wav`
+
+Create a false color image from the `N19-June-High-Vegetation.pn` palette.
+
 ## Realtime decoding
 
 As of recently a realtime output was added allowing realtime decoding of images.
@@ -121,7 +125,7 @@ aptdec /tmp/aptaudio
 sox -t pulseaudio alsa_output.pci-0000_00_1b.0.analog-stereo.monitor -c 1 -t wav /tmp/aptaudio
 ```
 
-Perform a realtime decode with the audio being played out of `alsa_output.pci-0000_00_1b.0.analog`.
+Perform a realtime decode with the audio being played out of `alsa_output.pci-0000_00_1b.0.analog`. To stop the decode kill the `sox` process
 
 ## Further reading
 

common.h

@@ -34,6 +34,7 @@ typedef struct {
 	int nrow; // Number of rows
 	int chA, chB; // ID of each channel
 	char name[256]; // Stripped filename
+	char *palette; // Filename of palette
 } image_t;
 typedef struct {
 	char *type; // Output image type
@@ -43,4 +44,5 @@ typedef struct {
 	char *path; // Output directory
 	int   realtime; // Realtime decoding
 	char *filename; // Output filename
+	char *palette; // Filename of palette
 } options_t;

dsp.c

@@ -248,7 +248,7 @@ int getpixelrow(float *pixelv, int nrow, int *zenith, int reset) {
 
 	// The point in which the pixel offset is recalculated
 	if (corr < 0.75 * max) {
-		//synced = 0;
+		synced = 0;
 		FreqLine = 1.0;
 	}
 	max = corr;

main.c

@@ -80,7 +80,7 @@ int main(int argc, char **argv) {
 
 	// Parse arguments
 	int opt;
-	while ((opt = getopt(argc, argv, "o:m:d:i:s:e:r")) != EOF) {
+	while ((opt = getopt(argc, argv, "o:m:d:i:s:e:rp:")) != EOF) {
 		switch (opt) {
 			case 'd':
 				opts.path = optarg;
@@ -107,6 +107,9 @@ int main(int argc, char **argv) {
 			case 'o':
 				opts.filename = optarg;
 				break;
+			case 'p':
+				opts.palette = optarg;
+				break;
 			default:
 				usage();
 		}
@@ -235,21 +238,19 @@ static int processAudio(char *filename, options_t *opts){
 		histogramEqualise(img.prow, img.nrow, CHB_OFFSET, CH_WIDTH);
 	}
 
-	// False color
-	if(CONTAINS(opts->type, 'c')){
-		if(img.chA == 2 && img.chB >= 4){
-			ImageOut(opts, &img, 0, CH_WIDTH, "False Color", "c", NULL);
-		}else{
-			fprintf(stderr, "Lacking channels required for false color computation\n");
-		}
-	}
-
 	// Raw image
 	if (CONTAINS(opts->type, 'r')) {
 		sprintf(desc, "%s (%s) & %s (%s)", ch.id[img.chA], ch.name[img.chA], ch.id[img.chB], ch.name[img.chB]);
 		ImageOut(opts, &img, 0, IMG_WIDTH, desc, "r", NULL);
 	}
 
+	// Palette image
+	if (CONTAINS(opts->type, 'p')) {
+		img.palette = opts->palette;
+		strcpy(desc, "Palette composite");
+		ImageOut(opts, &img, 0, 909, desc, "p", NULL);
+	}
+
 	// Channel A
 	if (CONTAINS(opts->type, 'a')) {
 		sprintf(desc, "%s (%s)", ch.id[img.chA], ch.name[img.chA]);
@@ -317,24 +318,25 @@ static void usage(void) {
 	"Aptdec [options] audio files ...\n"
 	"Options:\n"
 	" -e [t|h|d|p|f|l] Effects\n"
-	"	 t: Crop telemetry\n"
-	"	 h: Histogram equalise\n"
-	"	 d: Denoise\n"
-	"	 p: Precipitation\n"
-	"	 f: Flip image\n"
-	"	 l: Linear equalise\n"
-	" -i [r|a|b|c|t|m] Output image\n"
-	"	 r: Raw\n"
-	"	 a: Channel A\n"
-	"	 b: Channel B\n"
-	"	 c: False color\n"
-	"	 t: Temperature\n"
-	"	 m: MCIR\n"
+	"    t: Crop telemetry\n"
+	"    h: Histogram equalise\n"
+	"    d: Denoise\n"
+	"    p: Precipitation\n"
+	"    f: Flip image\n"
+	"    l: Linear equalise\n"
+	" -i [r|a|b|c|t|m|p] Output image\n"
+	"    r: Raw\n"
+	"    a: Channel A\n"
+	"    b: Channel B\n"
+	"    t: Temperature\n"
+	"    m: MCIR\n"
+	"    p: Paletted image\n"
 	" -d <dir>         Image destination directory.\n"
 	" -o <name>        Output filename\n"
 	" -s [15-19]       Satellite number\n"
 	" -m <file>        Map file\n"
 	" -r               Realtime decode\n"
+	" -p               Path to palette\n"
 	"\nRefer to the README for more infomation\n");
 
 	exit(EINVAL);

pngio.c

@@ -193,6 +193,67 @@ int readRawImage(char *filename, float **prow, int *nrow) {
 	return 1;
 }
 
+int readPalette(char *filename, rgb_t **crow) {
+	FILE *fp = fopen(filename, "r");
+	if(!fp) {
+		fprintf(stderr, "Cannot open %s\n", filename);
+		return 0;
+	}
+
+	// Create reader
+	png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if(!png) return 0;
+	png_infop info = png_create_info_struct(png);
+	if(!info) return 0;
+	png_init_io(png, fp);
+
+	// Read info from header
+	png_read_info(png, info);
+	int width = png_get_image_width(png, info);
+	int height = png_get_image_height(png, info);
+	png_byte color_type = png_get_color_type(png, info);
+	png_byte bit_depth  = png_get_bit_depth(png, info);
+
+	// Check the image
+	if(width != 256 && height != 256){
+		fprintf(stderr, "Palette must be 256x256.\n");
+		return 0;
+	}else if(bit_depth != 8){
+		fprintf(stderr, "Palette must be 8 bit color.\n");
+		return 0;
+	}else if(color_type != PNG_COLOR_TYPE_RGBA){
+		fprintf(stderr, "Palette must be RGB.\n");
+		return 0;
+	}
+
+	// Create row buffers
+	png_bytep *PNGrows = NULL;
+	PNGrows = (png_bytep *) malloc(sizeof(png_bytep) * height);
+	for(int y = 0; y < height; y++)
+		PNGrows[y] = (png_byte *) malloc(png_get_rowbytes(png, info));
+
+	// Read image
+	png_read_image(png, PNGrows);
+
+	// Tidy up
+	fclose(fp);
+	png_destroy_read_struct(&png, &info, NULL);
+
+	// Put into crow
+	for(int y = 0; y < height; y++) {
+		crow[y] = (rgb_t *) malloc(sizeof(rgb_t) * width);
+
+		for(int x = 0; x < width; x++)
+			crow[y][x] = (rgb_t){
+				PNGrows[y][x*4],
+				PNGrows[y][x*4 + 1], 
+				PNGrows[y][x*4 + 2]
+			};
+	}
+
+	return 1;
+}
+
 png_text meta[] = {
 	{PNG_TEXT_COMPRESSION_NONE, "Software", VERSION},
 	{PNG_TEXT_COMPRESSION_NONE, "Channel", "Unknown", 7},
@@ -216,6 +277,7 @@ int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, c
 	int fc = (chid[0] == 'c');
 	int greyscale = 0;
 	int skiptele = 0;
+	int imgpalette = (chid[0] == 'p');
 	if(opts->effects != NULL && CONTAINS(opts->effects, 't')){
 		width -= TOTAL_TELE;
 		skiptele = 1;
@@ -235,7 +297,7 @@ int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, c
 		return 0;
 	}
 
-	if(palette == NULL && !CONTAINS(opts->effects, 'p') && !fc && opts->map[0] == '\0' && chid[0] != 'm'){
+	if(palette == NULL && !CONTAINS(opts->effects, 'p') && !fc && opts->map[0] == '\0' && chid[0] != 'm' && !imgpalette){
 		greyscale = 1;
 
 		// Greyscale image
@@ -300,6 +362,13 @@ int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, c
 
 	printf("Writing %s", outName);
 
+	rgb_t *pal_row[256];
+	if(imgpalette){
+		if(!readPalette(img->palette, pal_row)){
+			return 0;
+		}
+	}
+
 	// Build image
 	for (int y = 0; y < img->nrow; y++) {
 		png_color pix[width]; // Color
@@ -326,6 +395,14 @@ int ImageOut(options_t *opts, image_t *img, int offset, int width, char *desc, c
 					CLIP(img->prow[y][x + CHA_OFFSET], 0, 255),
 					CLIP(img->prow[y][x + CHB_OFFSET], 0, 255)
 				};
+			}else if(imgpalette){
+				int cha = img->prow[y][x + CHA_OFFSET];
+				int cbb = img->prow[y][x + CHB_OFFSET];
+				pix[x] = (png_color){
+					pal_row[cbb][cha].r,
+					pal_row[cbb][cha].g,
+					pal_row[cbb][cha].b
+				};
 			}else{
 				pix[x] = (png_color){
 					crow[y][x + skip + offset].r,
@@ -414,4 +491,4 @@ void closeWriter(){
 	png_write_end(rt_png_ptr, rt_info_ptr);
 	fclose(rt_pngfile);
 	png_destroy_write_struct(&rt_png_ptr, &rt_info_ptr);
-}
+}