Add color mode

.gitignore

@@ -7,3 +7,4 @@ Debug/
 apt_audio
 noaa_apt
 imgc
+apt-colorm

README.md

@@ -9,18 +9,19 @@ Information and description:
 
 ```
 NOAA automatic picture transmission (APT) encoder
-Usage: Debug/noaa_apt (-i <file> [-s <file>] | -I) [(-d <device> | -O) -m <mode> -lcr]
+Usage: Debug/noaa_apt (-i <file> [-s <file>] | -I) [(-d <device> | -O) -m <mode> -lcrM]
   -i <filename> Input TGA image (909px width, 24bit RGB)
   -s <filename> Second input TGA image (B channel, mode ignored)
   -d <device>   OSS audio device (default /dev/dsp) or file
-  -m <mode>     Channel B data mode (R,G,B,N,Y)
+  -m <mode>     Channel B data mode (R,G,B,N,Y,C)
   -I            Read image data from stdin
   -O            Write audio data to stdout
+  -M            Multi image reading from stdin
   -l            Enable infinite image loop
   -c            Enable user console
   -r            Device is regular file (write WAV audio file)
   -h            Show this help
-                Build: 00:35:30 Jul 26 2019, GCC 5.3.0
+                Build: 21:52:59 Aug 18 2019, GCC 5.3.0
 ```
 
 * Run as: ```guest@porteus:~$ padsp noaa_apt -lci SourceTestImage.tga``` 
@@ -33,6 +34,18 @@ Usage: Debug/noaa_apt (-i <file> [-s <file>] | -I) [(-d <device> | -O) -m <mode>
 <tr><td>Source audio</td><td><audio src="./doc/SourceTestAudio.ogg" controls preload="none"></audio> <a href="./doc/SourceTestAudio.ogg">Sample</a></td></tr>
 </table>
 
+### Special mode C - color
+
+Mode use 12bit (4096 colors, square root of 4096 is 64) look up table. Each color have 4 bit resolution (16 values). Channel A contain Y-pos values and channel B contain X-pos values (position in LUT). Image quality depends on LUT (color position in table). Current LUT is not ideal. Only X-pos is good. For decoding use apt-colorm and for better image quality disable gamma correction in WxToImg.
+
+<table>
+<tr><td>Look up table (64x64, upscaled 4x)</td><td><img src="./doc/test-space-4k-lines.png" width="256"></td></tr>
+<tr><td>Original image</td><td><img src="./doc/139-orig.png" width="500"></td></tr>
+<tr><td>Channel A image</td><td><img src="./doc/139-color-a.png" width="500"></td></tr>
+<tr><td>Channel B image</td><td><img src="./doc/139-color-b.png" width="500"></td></tr>
+<tr><td>Decoded color image</td><td><img src="./doc/139-color-decoded.png" width="500"></td></tr>
+</table>
+
 ### APT
 
 APT means Automatic Picture Transmission. It is a system, developed in the 1960s, made to transmit low-resolution analog image for weather satellites. A complete APT image takes around 12 minutes to be built up at a rate of 2 lines per second. The data is broadcasted by the satellite. The stream is obtained by the AVHRR/3 instrument. Two channels with a low resolution are emitting all the time using VHF signals at reduced rates (around 120 lines/minutes).

apt-colorm.c

@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <math.h>
+#include <getopt.h>
+#include "image.h"
+#include "aptcode.h"
+
+#define _APT_FILE_NO_SET "σame"
+
+void Usage(char *p_name);
+
+int main(int argc, char *argv[]) {
+  if(argc == 1){
+    Usage(argv[0]);
+    return 0;
+  }
+  char channel_a[1024]=_APT_FILE_NO_SET;
+  char channel_b[1024]=_APT_FILE_NO_SET;
+  char output[1024]=_APT_FILE_NO_SET;  
+  int opt = 0; 
+  while ((opt = getopt(argc, argv, "a:b:o:h")) != -1){
+    switch (opt) {
+    case 'h': //Help
+      Usage(argv[0]);
+      return 0;
+      break;
+    case 'a': //Channel A TGA image
+      strncpy(channel_a,optarg,sizeof(channel_a)-1);
+      break;
+    case 'b': //Channel B TGA image
+      strncpy(channel_b,optarg,sizeof(channel_b)-1);
+      break;  
+    case 'o': //Output TGA image
+      strncpy(output,optarg,sizeof(output)-1);
+      break;  
+    default:
+      Usage(argv[0]);
+      return 0;  
+    } 
+  }	  
+  if(strncmp(channel_a,_APT_FILE_NO_SET,4) == 0) {
+    printf("%s: required argument and option -- '-a <filename>'\n",argv[0]);
+    exit(2);
+  }
+  if(strncmp(channel_b,_APT_FILE_NO_SET,4) == 0) {
+    printf("%s: required argument and option -- '-b <filename>'\n",argv[0]);
+    exit(2);
+  }
+  if(strncmp(output,_APT_FILE_NO_SET,4) == 0) {
+    printf("%s: required argument and option -- '-o <filename>'\n",argv[0]);
+    exit(2);
+  }
+  TgaImageHead ChannelA, ChannelB, OutputColor;
+  ChannelA = OpenTgaImage(channel_a);
+  ChannelB = OpenTgaImage(channel_b);
+  OutputColor = ChannelA;
+  OutputColor = WriteTgaImage(output, OutputColor);
+  if(ChannelA.File == NULL) {  // On error 
+    exit(1);
+  }
+  if(ChannelB.File == NULL) {  // On error 
+    exit(1);
+  }
+  if(OutputColor.File == NULL) {  // On error 
+    exit(1);
+  }
+
+  int i,j;
+  unsigned int pix_a;
+  unsigned int pix_b;
+  HsvColor hsvc;
+  AptColor aptc;
+  RgbColor rgbc;
+  // 24 bit RGB, but in grayscale expected
+  for(i=0;i<ChannelA.Width;i++) {
+     for(j=0;j<ChannelA.Height;j++) {
+       pix_a = ReadTGAPixel(ChannelA.File);
+       pix_b = ReadTGAPixel(ChannelB.File);
+       aptc.h = GetRedSubPixel(pix_a);  // X
+       aptc.sv = GetRedSubPixel(pix_b); // Y
+
+       rgbc = AptToRgb(aptc);
+
+       WriteTGAPixel(rgbc.r,rgbc.g,rgbc.b, OutputColor.File);
+     }
+   }
+  fclose(ChannelA.File);
+  fclose(ChannelB.File);
+  fclose(OutputColor.File); 
+  return 0;
+}
+
+void Usage(char *p_name) {
+  printf("NOAA color mode decoder\n");
+  printf("Usage: %s -a <filename> -b <filename> -o <filename> -h\n",p_name);
+  printf("  -a <filename> Input channel A TGA image (909px width, 24bit RGB)\n");
+  printf("  -b <filename> Input channel B TGA image (909px width, 24bit RGB)\n");
+  printf("  -o <filename> Output color TGA image \n");
+  printf("  -h            Show this help\n");
+  printf("                Build: %s %s, GCC %s\n", __TIME__, __DATE__, __VERSION__); 
+}
+

apt-colorm.make

@@ -0,0 +1,2 @@
+#!/bin/sh
+gcc apt-colorm.c image.c -Wall -o apt-colorm -std=c99

aptcode.c

@@ -66,6 +66,8 @@ AptLine CreateAptLine(uint8_t frame, uint8_t currentline, AptTelemetry ChanA, Ap
   uint8_t Rval = 0;
   uint8_t Gval = 0;
   uint8_t Bval = 0;
+  RgbColor pixel_r;
+  AptColor pixel_a;
   unsigned int pix;
   // Sync A and Sync B
   for(i=0;i<APT_SYNC_A;i++) {
@@ -84,7 +86,9 @@ AptLine CreateAptLine(uint8_t frame, uint8_t currentline, AptTelemetry ChanA, Ap
         Rval = GetRedSubPixel(pix);
         Gval = GetGreenSubPixel(pix);
         Bval = GetBlueSubPixel(pix);
-        NewLine.VideoA[j] = Rval*0.302 + Gval*0.59 + Bval*0.11;
+        if(DataB!='C') { 
+          NewLine.VideoA[j] = Rval*0.302 + Gval*0.59 + Bval*0.11;
+        }
         switch(DataB) {
           case 'R': //Red
             NewLine.VideoB[j] = Rval;
@@ -98,6 +102,14 @@ AptLine CreateAptLine(uint8_t frame, uint8_t currentline, AptTelemetry ChanA, Ap
           case 'Y': //Yb
             NewLine.VideoB[j] = (-38*Rval-74*Gval+112*Bval+128)/256 + 128; 
             break;
+          case 'C': //Color
+            pixel_r.r = Rval;
+            pixel_r.g = Gval;
+            pixel_r.b = Bval;
+            pixel_a = RgbToApt(pixel_r);
+            NewLine.VideoA[j] = pixel_a.h;
+            NewLine.VideoB[j] = pixel_a.sv;
+            break;  
           case 'N':  
           default : //Negative
             NewLine.VideoB[j] = 255-NewLine.VideoA[j];

image.c

@@ -304,4 +304,32 @@ HsvColor AptToHsv(AptColor apt, uint8_t bits) {
   }
 
   return hsv;
+}
+
+AptColor RgbToApt(RgbColor rgb) {
+  AptColor apt;
+  uint8_t R = (rgb.r >> 4) & 0xF;
+  uint8_t G = (rgb.g >> 4) & 0xF;
+  uint8_t B = (rgb.b >> 4) & 0xF;
+  uint16_t val = (R << 8) + (G << 4) + B;
+  uint16_t pos = LUTFromRgb[val];
+  uint16_t y_val = pos % 64;
+  uint16_t x_val = (pos - y_val) / 64;
+  apt.h = (x_val & 0x3F) * 4;
+  apt.sv = (y_val & 0x3F) * 4; 
+  return apt;
+}
+
+RgbColor AptToRgb(AptColor apt) {
+  RgbColor rgb;
+  uint8_t x_val = (apt.h+2)/4;
+  uint8_t y_val = (apt.sv+2)/4;
+  if(x_val > 255) {x_val = 255;}
+  if(y_val > 255) {y_val = 255;}
+  uint16_t val = LUTFromApt[x_val][y_val];
+  uint8_t R = (val >> 8) & 0xF;
+  uint8_t G = (val >> 4) & 0xF;
+  uint8_t B = (val >> 0) & 0xF;
+  rgb.r = R * 17; rgb.g = G * 17; rgb.b = B * 17;
+  return rgb;
 }

image.h

@@ -1,6 +1,8 @@
 #ifndef NA_IMAGE_R_H_   
 #define NA_IMAGE_R_H_
 
+#include "imgtable.h"
+#include "imgtable_apt.h"
 #define IMG_TGA_HEAD_SIZE 18
 
 typedef struct {
@@ -62,4 +64,6 @@ RgbColor HsvToRgb(HsvColor hsv);
 AptColor HsvToApt(HsvColor hsv, uint8_t bits);
 //Convert APT to HSV color space
 HsvColor AptToHsv(AptColor apt, uint8_t bits);
+AptColor RgbToApt(RgbColor rgb);
+RgbColor AptToRgb(AptColor apt);
 #endif