* Added --dither option and updated usage()

src/img2txt.c

@@ -45,9 +45,16 @@ static void usage(int argc, char **argv)
     fprintf(stderr, "Options:\n");
     fprintf(stderr, "  -h, --help\tThis help\n");
     fprintf(stderr, "  -W, --width=WIDTH\tWidth of resulting image\n");
-    fprintf(stderr, "  -H, --HEIGHT=HEIGHT\tHeight of resulting image\n");
+    fprintf(stderr, "  -H, --height=HEIGHT\tHeight of resulting image\n");
+    fprintf(stderr, "  -d, --dither=DITHER\tDithering algorithm to use :\n");
+    fprintf(stderr, "\t\t\tnone : Nearest color\n");
+    fprintf(stderr, "\t\t\tordered2 : Ordered 2x2\n");
+    fprintf(stderr, "\t\t\tordered4 : Ordered 4x4\n");
+    fprintf(stderr, "\t\t\tordered8 : Ordered 8x8\n");
+    fprintf(stderr, "\t\t\trandom   : Random\n");
+    fprintf(stderr, "\t\t\tfstein   : Floyd Steinberg (default)\n");
     fprintf(stderr, "  -f, --format=FORMAT\tFormat of the resulting image :\n");
-    fprintf(stderr, "\t\t\tansi : coulored ANSI\n");
+    fprintf(stderr, "\t\t\tansi : coulored ANSI (default)\n");
     fprintf(stderr, "\t\t\tcaca : internal libcaca format\n");
     fprintf(stderr, "\t\t\tutf8 : UTF8 with CR\n");
     fprintf(stderr, "\t\t\tutf8 : UTF8 with CRLF (MS Windows)\n");
@@ -68,6 +75,7 @@ int main(int argc, char **argv)
     struct image *i;
     unsigned int cols = 0, lines = 0;
     char *format = NULL;
+    char *dither = NULL;
 
 
     if(argc < 2)
@@ -85,9 +93,10 @@ int main(int argc, char **argv)
             { "width",  1, NULL, 'W' },
             { "height", 1, NULL, 'H' },
             { "format", 1, NULL, 'f' },
+            { "dither", 1, NULL, 'd' },
             { "help",   0, NULL, 'h' },
         };
-        int c = mygetopt(argc, argv, "W:H:f:h", long_options, &option_index);
+        int c = mygetopt(argc, argv, "W:H:f:d:h", long_options, &option_index);
         if(c == -1)
             break;
 
@@ -102,6 +111,9 @@ int main(int argc, char **argv)
         case 'f': /* --format */
             format = myoptarg;
             break;
+        case 'd': /* --dither */
+            dither = myoptarg;
+            break;
         case 'h': /* --help */
             usage(argc, argv);
             return 0;
@@ -113,7 +125,6 @@ int main(int argc, char **argv)
     }
 
 
-
     cv = cucul_create_canvas(0, 0);
     if(!cv)
     {
@@ -148,6 +159,7 @@ int main(int argc, char **argv)
     cucul_set_canvas_size(cv, cols, lines);
     cucul_set_color_ansi(cv, CUCUL_DEFAULT, CUCUL_TRANSPARENT);
     cucul_clear_canvas(cv);
+    cucul_set_dither_algorithm(i->dither, dither?dither:"fstein");
     cucul_dither_bitmap(cv, 0, 0, cols, lines, i->dither, i->pixels);
 
     unload_image(i);