Tried some different color error functions

tools/imagecon/color.c

@@ -1,12 +1,28 @@
 #include "imagecon.h"
 
+
 int
 color_delta(amiga_color_t c1, amiga_color_t c2)
 {
   int dr = abs((c1.r)-(c2.r));
   int dg = abs((c1.g)-(c2.g));
   int db = abs((c1.b)-(c2.b));
-  return sqrt((dr*dr)+(dg*dg)+(db*db));
+  
+  enum  {
+    DISTANCE,
+    WEIGHTED,
+    SIMPLE
+  } errorFunc = WEIGHTED;
+  
+  switch (errorFunc) {
+  case SIMPLE:
+    return dr+dg+db;
+  case DISTANCE:
+    return sqrt((dr*dr)+(dg*dg)+(db*db));
+  case WEIGHTED:
+  default:
+    return dr*3+dg*4+db*2;
+  }
 }
 
 

tools/imagecon/dither.c

@@ -20,7 +20,8 @@ dither_getHamColor(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last
 float
 _gamma(float x)
 {
-  return x * 0.55;
+     return x * 0.55;
+     //  return x;
 }
 
 static void
@@ -48,9 +49,10 @@ dither_image(imagecon_image_t* ic, amiga_color_t (*selector)(imagecon_image_t*,
       amiga_color_t new = selector(ic, color_ditheredToAmiga(old), last);
 
       dither_color_t error;
-      error.r = old.r - new.r;
-      error.g = old.g - new.g;
-      error.b = old.b - new.b;
+      float gamma = 1.0;
+      error.r = old.r - (new.r*gamma);
+      error.g = old.g - (new.g*gamma);
+      error.b = old.b - (new.b*gamma);
 
       color_setDitheredPixel(ic, x, y, color_amigaToDithered(new));
       last = new;

tools/imagecon/imagecon.c

@@ -70,7 +70,8 @@ generateQuantizedImage(imagecon_image_t* ic, int usePalette)
   }
 
   liq_attr *attr = liq_attr_create();
-  liq_image *image = liq_image_create_rgba_rows(attr, (void**)ic->rowPointers, ic->width, ic->height, 0);
+  // TODO: What to do with gamma here ?
+  liq_image *image = liq_image_create_rgba_rows(attr, (void**)ic->rowPointers, ic->width, ic->height, /* gamma */0.0);
 
   if (usePalette) {
     for (int i = 0; i < ic->numColors; i++) {
@@ -83,12 +84,15 @@ generateQuantizedImage(imagecon_image_t* ic, int usePalette)
     }
   }
 
+
   liq_set_max_colors(attr, config.maxColors);
   // no liq_set_quality(attr, 0, 100);
   //liq_set_min_posterization(attr, 4);
   liq_set_speed(attr, 1);
   liq_result *res = liq_quantize_image(attr, image);
-  //  liq_set_dithering_level(res, 1.0);
+
+  //liq_set_output_gamma(res, 0.1);
+  //liq_set_dithering_level(res, 0);
   liq_write_remapped_image(res, image, ic->amigaImage, ic->width*ic->height);
 
   const liq_palette *pal = liq_get_palette(res);