diff --git a/tools/imagecon/Makefile b/tools/imagecon/Makefile
index e432f56..30d03c7 100644
--- a/tools/imagecon/Makefile
+++ b/tools/imagecon/Makefile
@@ -1,5 +1,5 @@
 IMAGECON=./out/imagecon
-OBJS=out/imagecon.o out/png.o
+OBJS=out/imagecon.o out/png.o out/color.o out/dither.o out/ham.o out/palette.o out/file.o
 HOST_WARNINGS=-pedantic-errors -Wfatal-errors -Wall -Werror -Wextra -Wno-unused-parameter -Wshadow -limagequant
 HOST_CFLAGS=$(HOST_WARNINGS)
 LIBS=-lpng -limagequant
@@ -28,12 +28,14 @@ REFERENCE_HAM_BASE=reference/ham
 $(IMAGECON): out bin $(OBJS) 
 	gcc $(OBJS) -o $(IMAGECON) $(LIBS)
 
-
-out/imagecon.o: imagecon.h
-out/png.o: imagecon.h
+-include $(OBJS:.o=.d)
 
 out/%.o: %.c
 	gcc -c $(HOST_CFLAGS) $< -o $@ 
+	@gcc -MM $(HOST_CFLAGS) $*.c > out/$*.d
+	@mv -f out/$*.d out/$*.d.tmp
+	@sed -e 's/.*/out\/&/' < out/$*.d.tmp > out/$*.d
+	@rm -f out/$*.d.tmp
 
 out:
 	mkdir out
diff --git a/tools/imagecon/color.c b/tools/imagecon/color.c
new file mode 100644
index 0000000..8b04fe6
--- /dev/null
+++ b/tools/imagecon/color.c
@@ -0,0 +1,187 @@
+#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));
+}
+
+
+void
+color_print(amiga_color_t color)
+{
+  printf("R = %03d  G = %03d  B = %03d A = %03d", color.r, color.g, color.b, color.a);
+}
+
+
+int
+color_findClosestPaletteIndex(imagecon_image_t* ic, amiga_color_t color)
+{
+  int delta = INT_MAX;
+  int index = 0;
+
+  for (int i = 0; i < ic->numColors; i++) {
+    int dc = color_delta(color, ic->palette[i]);
+    if (dc < delta) {
+      delta = dc;
+      index = i;
+    }
+  }
+  return index;
+}
+
+amiga_color_t
+color_findClosestPalettePixel(imagecon_image_t* ic, amiga_color_t color)
+{
+  return ic->palette[color_findClosestPaletteIndex(ic, color)];
+}
+
+ham_control_t
+color_findClosestHamPixel(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last)
+{
+  int delta = INT_MAX;
+
+  ham_control_t ham = {0};
+
+  for (int i = 0; i < ic->numColors; i++) {
+    int dc = color_delta(color, ic->palette[i]);
+    if (dc < delta) {
+      delta = dc;
+      ham.data = i;
+      ham.pixel = ic->palette[i];
+    }
+  }
+
+  delta =  color_delta(color, ham.pixel);
+  if (last.r != -1) {
+    for (int c = 0; c <= 0xF; c++) {
+      amiga_color_t copy = last;
+      copy.r = c<<4;
+      int dc = color_delta(color, copy);
+      if (dc < delta) {
+	ham.control = 2;
+	ham.data = c;
+	ham.pixel = copy;
+	delta = dc;
+      }
+    }
+    for (int c = 0; c <= 0xF; c++) {
+      amiga_color_t copy = last;
+      copy.g = c<<4;
+      int dc = color_delta(color, copy);
+      if (dc < delta) {
+	ham.control = 3;
+	ham.data = c;
+	ham.pixel = copy;
+	delta = dc;
+      }
+    }
+    for (int c = 0; c <= 0xF; c++) {
+      amiga_color_t copy = last;
+      copy.b = c<<4;
+      int dc = color_delta(color, copy);
+      if (dc < delta) {
+	ham.control = 1;
+	ham.data = c;
+	ham.pixel = copy;
+	delta = dc;
+      }
+    }
+  }	
+
+  return ham;
+}
+
+
+amiga_color_t
+color_getOriginalPixel(imagecon_image_t* ic, int x, int y)
+{
+  png_byte* ptr = ic->rowPointers[y] + (x*4);
+  amiga_color_t color;
+  color.r = ptr[0];
+  color.g = ptr[1];
+  color.b = ptr[2];
+  color.a = ptr[3];
+  return color;
+}
+
+
+void
+color_setOriginalPixel(imagecon_image_t* ic, int x, int y, amiga_color_t color)
+{
+  png_byte* ptr = ic->rowPointers[y] + (x*4);
+  ptr[0] = color.r;
+  ptr[1] = color.g;
+  ptr[2] = color.b;
+  ptr[3] = color.a;
+}
+
+
+amiga_color_t
+color_getDitheredPixel(imagecon_image_t* ic, int x, int y)
+{
+  return ic->dithered[(y*ic->width)+x];
+}
+
+void
+color_setDitheredPixel(imagecon_image_t* ic, int x, int y, amiga_color_t color)
+{
+  amiga_color_t *d = &ic->dithered[(y*ic->width)+x];
+
+  if (color.r > 255) {
+    color.r = 255;
+  } 
+  if (color.r < 0) {
+    color.r = 0;
+  }
+  if (color.g > 255) {
+    color.g = 255;
+  } 
+  if (color.g < 0) {
+    color.g = 0;
+  }
+  if (color.b > 255) {
+    color.b = 255;
+  } 
+  if (color.b < 0) {
+    color.b = 0;
+  }
+
+  d->r = color.r;
+  d->g = color.g;
+  d->b = color.b;
+  d->a = color.a;
+}
+
+amiga_color_t
+color_getPalettedPixel(imagecon_image_t* ic, int x, int y)
+{
+  int paletteIndex = ic->amigaImage[(ic->width*y)+x];
+  amiga_color_t color;
+  color.r = ic->palette[paletteIndex].r;
+  color.g = ic->palette[paletteIndex].g;
+  color.b = ic->palette[paletteIndex].b;
+  color.a = ic->palette[paletteIndex].a;
+  return color;
+}
+
+void
+color_setPalettedPixel(imagecon_image_t* ic, int x, int y, amiga_color_t color)
+{
+  int paletteIndex = color_findClosestPaletteIndex(ic, color);
+  ic->amigaImage[(ic->width*y)+x] = paletteIndex;
+}
+
+
+void
+color_transferPalettedToOriginal(imagecon_image_t* ic)
+{
+  for (int y = 0; y < ic->height; y++) {
+    for (int x = 0; x < ic->width; x++) {
+      color_setOriginalPixel(ic, x, y, color_getPalettedPixel(ic, x, y));
+    }
+  }
+}
diff --git a/tools/imagecon/color.h b/tools/imagecon/color.h
new file mode 100644
index 0000000..7d27e0a
--- /dev/null
+++ b/tools/imagecon/color.h
@@ -0,0 +1,34 @@
+#pragma once
+
+int
+color_delta(amiga_color_t c1, amiga_color_t c2);
+
+amiga_color_t
+color_findClosestPalettePixel(imagecon_image_t* ic, amiga_color_t color);
+
+int
+color_findClosestPaletteIndex(imagecon_image_t* ic, amiga_color_t color);
+
+ham_control_t
+color_findClosestHamPixel(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last);
+
+amiga_color_t
+color_getPalettedPixel(imagecon_image_t* ic, int x, int y);
+
+void
+color_setPalettedPixel(imagecon_image_t* ic, int x, int y, amiga_color_t color);
+
+void
+color_setDitheredPixel(imagecon_image_t* ic, int x, int y, amiga_color_t color);
+
+amiga_color_t
+color_getDitheredPixel(imagecon_image_t* ic, int x, int y);
+
+amiga_color_t
+color_getOriginalPixel(imagecon_image_t* ic, int x, int y);
+
+void
+color_setOriginalPixel(imagecon_image_t* ic, int x, int y, amiga_color_t color);
+
+void
+color_transferPalettedToOriginal(imagecon_image_t* ic);
diff --git a/tools/imagecon/dither.c b/tools/imagecon/dither.c
new file mode 100644
index 0000000..6918ab1
--- /dev/null
+++ b/tools/imagecon/dither.c
@@ -0,0 +1,125 @@
+#include "imagecon.h"
+
+static void
+_dither_createDither(imagecon_image_t* ic);
+
+amiga_color_t
+dither_getPalettedColor(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last)
+{
+  return color_findClosestPalettePixel(ic, color);
+}
+
+
+amiga_color_t
+dither_getHamColor(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last)
+{
+  ham_control_t ham = color_findClosestHamPixel(ic, color, last);
+  return ham.pixel;
+}
+
+void
+dither_image(imagecon_image_t* ic, amiga_color_t (*selector)(imagecon_image_t*, amiga_color_t color, amiga_color_t last))
+{
+  _dither_createDither(ic);
+  
+  for (int y = 0; y < ic->height; y++) {
+    amiga_color_t last = {-1, -1, -1, -1};
+    for (int x = 0; x < ic->width; x++) {
+
+      amiga_color_t old = color_getDitheredPixel(ic, x, y);
+      amiga_color_t new = selector(ic, old, last);
+
+      amiga_color_t error;
+      error.r = old.r - new.r;
+      error.g = old.g - new.g;
+      error.b = old.b - new.b;
+
+      color_setDitheredPixel(ic, x, y, new);
+      last = new;
+
+      amiga_color_t color;
+      float factor;
+      
+      if (x+1 < ic->width) {
+	color = color_getDitheredPixel(ic, x+1, y); 
+	factor = 7.0/16.0;
+	color.r = color.r + ((float)error.r * factor);
+	color.g = color.g + ((float)error.g * factor);
+	color.b = color.b + ((float)error.b * factor);
+	color_setDitheredPixel(ic, x+1, y, color);
+      }
+
+      if (x > 0 && y+1 < ic->height) {
+	color = color_getDitheredPixel(ic, x-1, y+1);
+	factor = 3.0/16.0;
+	color.r = color.r + ((float)error.r * factor);
+	color.g = color.g + ((float)error.g * factor);
+	color.b = color.b + ((float)error.b * factor);
+	color_setDitheredPixel(ic, x-1, y+1, color);
+      }
+
+      if (y+1 < ic->height) {
+	color = color_getDitheredPixel(ic, x, y+1); 
+	factor = 5.0/16.0;
+	color.r = color.r + ((float)error.r * factor);
+	color.g = color.g + ((float)error.g * factor);
+	color.b = color.b + ((float)error.b * factor);
+	color_setDitheredPixel(ic, x, y+1, color);
+	
+	if (x+1 < ic->width) {
+	  color = color_getDitheredPixel(ic, x+1, y+1); 
+	  factor = 1.0/16.0;
+	  color.r = color.r + ((float)error.r * factor);
+	  color.g = color.g + ((float)error.g * factor);
+	  color.b = color.b + ((float)error.b * factor);
+	  color_setDitheredPixel(ic, x+1, y+1, color);
+	}
+      }
+    }
+
+  }
+
+}
+
+
+void
+dither_transferToPaletted(imagecon_image_t* ic)
+{
+  for (int y = 0; y < ic->height; y++) {
+    for (int x = 0; x < ic->width; x++) {
+      color_setPalettedPixel(ic, x, y, color_getDitheredPixel(ic, x, y));
+    }
+  }
+}
+
+
+ham_control_t* 
+dither_createHams(imagecon_image_t* ic)
+{
+  ham_control_t* hams = malloc(sizeof(ham_control_t)*ic->width*ic->height);
+
+  for (int y = 0; y < ic->height; y++) {
+    amiga_color_t lastPixel = { -1, -1, -1, -1};
+    for (int x = 0; x < ic->width; x++) {
+      amiga_color_t orig = color_getDitheredPixel(ic, x, y);
+      ham_control_t ham = color_findClosestHamPixel(ic, orig, lastPixel);
+      lastPixel = ham.pixel;
+      hams[(y*ic->width)+x] = ham;
+    }
+  }
+
+  return hams;
+}
+
+
+static void
+_dither_createDither(imagecon_image_t* ic)
+{
+  ic->dithered = malloc(sizeof(amiga_color_t)*ic->width*ic->height);
+  
+  for (int y = 0; y < ic->height; y++) {
+    for (int x = 0; x < ic->width; x++) {
+      color_setDitheredPixel(ic, x, y, color_getOriginalPixel(ic, x, y));
+    }
+  }
+}
diff --git a/tools/imagecon/dither.h b/tools/imagecon/dither.h
new file mode 100644
index 0000000..b3d09df
--- /dev/null
+++ b/tools/imagecon/dither.h
@@ -0,0 +1,16 @@
+#pragma once
+
+amiga_color_t
+dither_getPalettedColor(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last);
+
+amiga_color_t
+dither_getHamColor(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last);
+
+void
+dither_image(imagecon_image_t* ic, amiga_color_t (*selector)(imagecon_image_t* ic, amiga_color_t color, amiga_color_t last));
+
+void
+dither_transferToPaletted(imagecon_image_t* ic);
+
+ham_control_t* 
+dither_createHams(imagecon_image_t* ic);
diff --git a/tools/imagecon/file.c b/tools/imagecon/file.c
new file mode 100644
index 0000000..f774e12
--- /dev/null
+++ b/tools/imagecon/file.c
@@ -0,0 +1,39 @@
+#include "imagecon.h"
+
+FILE * 
+file_openWrite(const char * s, ...)
+{
+  char buffer[4096];
+  va_list args;
+  va_start(args, s);
+  vsprintf(buffer, s, args);
+  va_end(args);
+
+  if (config.verbose) {
+    printf("Opening %s for writing\n", buffer);
+  }
+
+  FILE* fp = fopen(buffer, "w+");
+  if (!fp) {
+    abort_("Failed to open %s for writing\n", buffer);
+  }
+  return fp;
+}
+
+
+FILE * 
+file_openRead(const char * s, ...)
+{
+  char buffer[4096];
+  va_list args;
+  va_start(args, s);
+  vsprintf(buffer, s, args);
+  va_end(args);
+
+  FILE* fp = fopen(buffer, "r");
+  if (!fp) {
+    abort_("Failed to open %s for reading\n", buffer);
+  }
+  return fp;
+}
+
diff --git a/tools/imagecon/file.h b/tools/imagecon/file.h
new file mode 100644
index 0000000..f68d4fd
--- /dev/null
+++ b/tools/imagecon/file.h
@@ -0,0 +1,7 @@
+#pragma once
+
+FILE * 
+file_openWrite(const char * s, ...);
+
+FILE * 
+file_openRead(const char * s, ...);
diff --git a/tools/imagecon/ham.c b/tools/imagecon/ham.c
new file mode 100644
index 0000000..1508cf5
--- /dev/null
+++ b/tools/imagecon/ham.c
@@ -0,0 +1,111 @@
+#include "imagecon.h"
+
+static void
+_ham_outputBitplanes(char* outFilename, imagecon_image_t* ic)
+{
+  if (config.verbose) {
+    printf("outputHamBitplanes\n");
+  }
+ 
+  int numBitPlanes = 6;
+  int byteWidth = (ic->width + 7) / 8;
+
+  char** bitplanes = malloc(sizeof(void*)*numBitPlanes);
+  for (int i = 0; i < numBitPlanes; i++) {
+    bitplanes[i] = calloc(byteWidth*ic->height, 1);
+  }
+
+
+  ham_control_t* hams;
+
+  if (config.dither) {
+    dither_image(ic, dither_getHamColor);
+    hams = dither_createHams(ic);
+  } else {
+    hams = malloc(sizeof(ham_control_t)*ic->width*ic->height);
+    
+    for (int y = 0; y < ic->height; y++) {
+      amiga_color_t lastPixel = { -1, -1, -1, -1};
+      for (int x = 0; x < ic->width; x++) {
+	amiga_color_t orig = color_getOriginalPixel(ic, x, y);
+	ham_control_t ham = color_findClosestHamPixel(ic, orig, lastPixel);
+	lastPixel = ham.pixel;      
+	hams[(y*ic->width)+x] = ham;
+      }
+    }
+  }
+
+
+  for (int y = 0, writeIndex = 0; y < ic->height; y++) {
+    for (int byte = 0;byte < byteWidth; byte++) {
+      for (int bit = 0; bit < 8; bit++) {	
+	int x = byte * 8 + 7 - bit;    
+	ham_control_t ham = hams[(y*ic->width)+x];
+	int _numBitPlanes = 4;
+	for (int plane_index = 0; plane_index < _numBitPlanes; plane_index++) {
+	  char* plane = bitplanes[plane_index];
+	  plane[writeIndex] |= ((ham.data >> plane_index) & 1) << bit;
+	}       
+
+	for (int plane_index = 0; plane_index < 2; plane_index++) {
+	  char* plane = bitplanes[4+plane_index];
+	  plane[writeIndex] |= ((ham.control >> plane_index) & 1) << bit;
+	}       
+
+	
+      }
+      writeIndex++;
+    }
+  }
+
+
+  FILE* fp = file_openWrite("%s-ham.bin", outFilename);
+
+  for (int y = 0; y < ic->height; y++) {
+    for (int plane_index = 0; plane_index < numBitPlanes; plane_index++) {
+      char* plane = bitplanes[plane_index];
+      fwrite(&plane[y*byteWidth], byteWidth, 1, fp);      
+    }
+  }
+  
+  fclose(fp);
+  if (config.verbose) {
+    printf("done\n\n");
+  }
+}
+
+#if 0
+void
+ham_process(char* outFilename, imagecon_image_t* ic)
+{
+  config.maxColors = 256;
+  generateQuantizedImage(ic, 0);
+  dither_image(ic, dither_getPalettedColor);
+  dither_transferToPaletted(ic);    
+  color_transferPalettedToOriginal(ic);
+
+  config.maxColors = 16;
+  generateQuantizedImage(ic, 0);
+ 
+
+  if (config.outputBitplanes) {
+    _ham_outputBitplanes(outFilename, ic);
+  }
+  
+  palette_output(outFilename, ic);  
+}
+
+#else
+void
+ham_process(char* outFilename, imagecon_image_t* ic)
+{
+  config.maxColors = 16;
+  generateQuantizedImage(ic, 0);
+
+  if (config.outputBitplanes) {
+    _ham_outputBitplanes(outFilename, ic);
+  }
+  
+  palette_output(outFilename, ic);  
+}
+#endif
diff --git a/tools/imagecon/ham.h b/tools/imagecon/ham.h
new file mode 100644
index 0000000..962a09d
--- /dev/null
+++ b/tools/imagecon/ham.h
@@ -0,0 +1,4 @@
+#pragma once
+
+void
+ham_process(char* outFilename, imagecon_image_t* ic);
diff --git a/tools/imagecon/imagecon.c b/tools/imagecon/imagecon.c
index 8662a40..92142bc 100644
--- a/tools/imagecon/imagecon.c
+++ b/tools/imagecon/imagecon.c
@@ -2,19 +2,8 @@
  * Amiga bitplane creation inspired (copied) from https://github.com/vilcans/amiga-startup
  */
 
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <stdarg.h>
-#include <math.h>
-#include <getopt.h>
-#include <libgen.h>
-#include <png.h>
-#include <pngquant/libimagequant.h>
 #include "imagecon.h"
 
-
 imagecon_config_t config = { 
   .maxColors = MAX_PALETTE, 
   .outputPalette = 0, 
@@ -26,6 +15,7 @@ imagecon_config_t config = {
   .ehbMode = 0,
   .hamMode = 0,
   .quantize = 0,
+  .dither = 0,
   .overridePalette = 0
 };
 
@@ -47,6 +37,7 @@ usage()
 	  "  --output-palette\n"\
 	  "  --extra-half-brite\n"\
 	  "  --ham\n"\
+          "  --dither\n"\
 	  "  --use-palette <palette file>\n"\
 	  "  --verbose\n", config.argv[0]);
   exit(1);
@@ -66,144 +57,8 @@ abort_(const char * s, ...)
 }
 
 
-FILE * 
-openFileWrite(const char * s, ...)
-{
-  char buffer[4096];
-  va_list args;
-  va_start(args, s);
-  vsprintf(buffer, s, args);
-  va_end(args);
-
-  if (config.verbose) {
-    printf("Opening %s for writing\n", buffer);
-  }
-
-  FILE* fp = fopen(buffer, "w+");
-  if (!fp) {
-    abort_("Failed to open %s for writing\n", buffer);
-  }
-  return fp;
-}
 
 
-FILE * 
-openFileRead(const char * s, ...)
-{
-  char buffer[4096];
-  va_list args;
-  va_start(args, s);
-  vsprintf(buffer, s, args);
-  va_end(args);
-
-  FILE* fp = fopen(buffer, "r");
-  if (!fp) {
-    abort_("Failed to open %s for reading\n", buffer);
-  }
-  return fp;
-}
-
-
-void 
-outputPalette(char* outFilename, imagecon_image_t* ic)
-{
-  if (config.verbose) {
-    printf("outputPalette...%d colors\n", ic->numColors);
-  }
-
-  FILE* fp = 0;
-  FILE* paletteFP = 0;
-  FILE* paletteAsmFP = 0;
-  FILE* paletteGreyFP = 0;
-
-  if (config.outputCopperList) {
-    fp = openFileWrite("%s-copper-list.s", outFilename);
-  }
-
-  if (config.outputPalette) {
-    paletteFP = openFileWrite("%s.pal", outFilename);
-  }
-
-  if (config.outputPaletteGrey) {
-    paletteGreyFP = openFileWrite("%s-grey.s", outFilename);
-    fprintf(paletteGreyFP, "\tmovem.l d0-a6,-(sp)\n\tlea CUSTOM,a6\n");
-  }
-
-  if (config.outputPaletteAsm) {
-    paletteAsmFP = openFileWrite("%s-palette.s", outFilename);
-    fprintf(paletteAsmFP, "\tmovem.l d0-a6,-(sp)\n\tlea CUSTOM,a6\n");
-  }
-
-  if (config.verbose) {
-    printf("outputPalette:\n");
-  }
-  
-  for (int i = 0; i < (config.ehbMode ? ic->numColors/2 : ic->numColors); i++) {
-    if (config.verbose) {
-      printf("%02d: hex=%03x r=%03d g=%03d b=%03d a=%03d\n", i , ic->palette[i].r << 8 | ic->palette[i].g << 4 | ic->palette[i].b, ic->palette[i].r, ic->palette[i].g, ic->palette[i].b, ic->palette[i].a);
-    }
-    if (paletteFP) {
-      fprintf(paletteFP, "%03x\n",  (ic->palette[i].r >> 4) << 8 | (ic->palette[i].g >>4) << 4 | (ic->palette[i].b >>4));
-    }
-    if (paletteAsmFP) {
-      fprintf(paletteAsmFP, "\tlea COLOR%02d(a6),a0\n\tmove.w #$%03x,(a0)\n", i, (ic->palette[i].r >> 4) << 8 | (ic->palette[i].g >>4) << 4 | (ic->palette[i].b >>4));
-    }
-    if (paletteGreyFP) {
-      // TODO: this is for compat, can be better
-      unsigned grey = (((ic->palette[i].r>>4) + (ic->palette[i].g>>4) + (ic->palette[i].b>>4))/3);
-      fprintf(paletteGreyFP, "\tlea COLOR%02d(a6),a0\n\tmove.w #$%03x,(a0)\n", i, grey << 8 | grey << 4 | grey);
-    }
-
-    if (fp) {
-      fprintf(fp, "\tdc.w $%x,$%x\n", 0x180+(i*2), (ic->palette[i].r >> 4) << 8 | (ic->palette[i].g >>4) << 4 | (ic->palette[i].b >>4));
-    }
-  }
-
-  if (paletteFP) {
-    fclose(paletteFP);
-  }
-
-  if (paletteGreyFP) {
-    fprintf(paletteGreyFP, "\tmovem.l (sp)+,d0-a6\n");
-    fclose(paletteGreyFP);
-  }
-
-  if (paletteAsmFP) {
-    fprintf(paletteAsmFP, "\tmovem.l (sp)+,d0-a6\n");
-    fclose(paletteFP);
-  }
-
-  if (fp) {
-    fclose(fp);
-  }
-
-  if (config.verbose) {
-    printf("done\n\n");
-  }
-}
-
-void loadPaletteFile(imagecon_image_t* ic)
-{
-  FILE* fp = openFileRead(config.overridePalette);
-  int paletteIndex;
-  
-  for (paletteIndex = 0; paletteIndex < MAX_PALETTE; paletteIndex++) {
-    unsigned int c;
-    char buffer[255];
-    char* line = fgets(buffer, 255, fp);
-    if (!line) {
-      break;
-    }
-    sscanf(buffer, "%x\n", &c);
-    
-    ic->palette[paletteIndex].r = (c >> 8 & 0xF) << 4;
-    ic->palette[paletteIndex].g = (c >> 4 & 0xF) << 4;
-    ic->palette[paletteIndex].b = (c >> 0 & 0xF) << 4;
-    ic->palette[paletteIndex].a = 255;
-  }
-
-  ic->numColors = paletteIndex;
-}
 
 void
 generateQuantizedImage(imagecon_image_t* ic, int usePalette)
@@ -227,9 +82,11 @@ 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_write_remapped_image(res, image, ic->amigaImage, ic->width*ic->height);
 
   const liq_palette *pal = liq_get_palette(res);
@@ -256,35 +113,12 @@ generateQuantizedImage(imagecon_image_t* ic, int usePalette)
   ic->numColors = pal->count;
 }
 
-amiga_color_t
-getOriginalColor(int x, int y, imagecon_image_t* ic)
-{
-  png_byte* ptr = ic->rowPointers[y] + (x*4);
-  amiga_color_t color;
-  color.r = ptr[0];
-  color.g = ptr[1];
-  color.b = ptr[2];
-  color.a = ptr[3];
-  return color;
-}
-
-amiga_color_t
-getColor(int x, int y, imagecon_image_t* ic)
-{
-  int paletteIndex = ic->amigaImage[(ic->width*y)+x];
-  amiga_color_t color;
-  color.r = ic->palette[paletteIndex].r;
-  color.g = ic->palette[paletteIndex].g;
-  color.b = ic->palette[paletteIndex].b;
-  color.a = ic->palette[paletteIndex].a;
-  return color;
-}
 
 void
-generatePalette(imagecon_image_t* ic)
+generatePalettedImage(imagecon_image_t* ic)
 {
   if (config.verbose) {
-    printf("generatePalette...\n");
+    printf("generatePalettedImage...\n");
   }
 
   int paletteIndex = 0;
@@ -359,7 +193,7 @@ outputBitplanes(char* outFilename, imagecon_image_t* ic)
   for (int i = 0; i < numBitPlanes; i++) {
     bitplanes[i] = calloc(byteWidth*ic->height, 1);
   }
-
+	
   for (int y = 0, writeIndex = 0; y < ic->height; y++) {
     for (int byte = 0;byte < byteWidth; byte++) {
       for (int bit = 0; bit < 8; bit++) {	
@@ -391,7 +225,7 @@ outputBitplanes(char* outFilename, imagecon_image_t* ic)
     }
   }
 
-  FILE* fp = openFileWrite("%s.bin", outFilename);
+  FILE* fp = file_openWrite("%s.bin", outFilename);
 
   for (int y = 0; y < ic->height; y++) {
     for (int plane_index = 0; plane_index < numBitPlanes; plane_index++) {
@@ -425,7 +259,7 @@ outputMask(char* outFilename, imagecon_image_t* ic)
     for (int byte = 0;byte < byteWidth; byte++) {
       for (int bit = 0; bit < 8; bit++) {	
 	int x = byte * 8 + 7 - bit;	
-	amiga_color_t c = getOriginalColor(x, y, ic);
+	amiga_color_t c = color_getOriginalPixel(ic, x, y);
 	int bitmask = c.a > 0 ? 0xFF : 0;
 	for (int plane_index = 0; plane_index < numBitPlanes; plane_index++) {
 	  char* plane = bitplanes[plane_index];
@@ -436,7 +270,7 @@ outputMask(char* outFilename, imagecon_image_t* ic)
     }
   }
 
-  FILE* fp = openFileWrite("%s-mask.bin", outFilename);
+  FILE* fp = file_openWrite("%s-mask.bin", outFilename);
 
   for (int y = 0; y < ic->height; y++) {
     for (int plane_index = 0; plane_index < numBitPlanes; plane_index++) {
@@ -472,194 +306,8 @@ generateEHBImage(imagecon_image_t* ic)
   generateQuantizedImage(ic, 1);
 }
 
-void
-printColor(amiga_color_t color)
-{
-  printf("R = %03d  G = %03d  B = %03d A = %03d", color.r, color.g, color.b, color.a);
-}
 
 
-
-int
-colorDelta(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 (dr+dg+db) / 3;
-}
-
-typedef struct {
-  int control;
-  int data;
-  amiga_color_t pixel;
-} ham_control_t;
-
-ham_control_t
-findBestHamPixel(imagecon_image_t* ic, amiga_color_t color, amiga_color_t orig, amiga_color_t last)
-{
-  int delta = INT_MAX;
-
-  ham_control_t ham = {0};
-
-  for (int i = 0; i < ic->numColors; i++) {
-    int dc = colorDelta(color, ic->palette[i]);
-    if (dc < delta) {
-      delta = dc;
-      ham.data = i;
-      ham.pixel = ic->palette[i];
-    }
-  }
-
-  delta =  colorDelta(orig, ham.pixel);
-  if (last.r != -1) {
-    for (int c = 0; c <= 0xF; c++) {
-      amiga_color_t copy = last;
-      copy.r = c<<4;
-      int dc = colorDelta(orig, copy);
-      if (dc < delta) {
-	ham.control = 2;
-	ham.data = c;
-	ham.pixel = copy;
-	delta = dc;
-      }
-    }
-    for (int c = 0; c <= 0xF; c++) {
-      amiga_color_t copy = last;
-      copy.g = c<<4;
-      int dc = colorDelta(orig, copy);
-      if (dc < delta) {
-	ham.control = 3;
-	ham.data = c;
-	ham.pixel = copy;
-	delta = dc;
-      }
-    }
-    for (int c = 0; c <= 0xF; c++) {
-      amiga_color_t copy = last;
-      copy.b = c<<4;
-      int dc = colorDelta(orig, copy);
-      if (dc < delta) {
-	ham.control = 1;
-	ham.data = c;
-	ham.pixel = copy;
-	delta = dc;
-      }
-    }
-  }	
-
-  return ham;
-}
-
-
-void
-outputHamBitplanes(char* outFilename, imagecon_image_t* ic)
-{
-  if (config.verbose) {
-    printf("outputHamBitplanes\n");
-  }
- 
-  int numBitPlanes = 6;
-  int numColors = 16;
-
-  if (config.verbose) {    
-    printf("ham number of colors = %d\n", numColors);
-    printf("ham number of bitplanes = %d\n", numBitPlanes);
-  }
- 
-  int byteWidth = (ic->width + 7) / 8;
-
-  char** bitplanes = malloc(sizeof(void*)*numBitPlanes);
-  for (int i = 0; i < numBitPlanes; i++) {
-    bitplanes[i] = calloc(byteWidth*ic->height, 1);
-  }
-
-  ham_control_t* hams = malloc(sizeof(ham_control_t)*ic->width*ic->height);
-
-  for (int y = 0; y < ic->height; y++) {
-    amiga_color_t lastPixel = { -1, -1, -1, -1};
-    for (int x = 0; x < ic->width; x++) {
-
-	amiga_color_t color = getColor(x, y, ic);
-	amiga_color_t orig = getOriginalColor(x, y, ic);
-
-	ham_control_t ham = findBestHamPixel(ic, color, orig, lastPixel);
-	lastPixel = ham.pixel;
-
-#if 0
-	printf("Color: ");
-	printColor(color);
-	printf("\n");
-	printf("Orig:  ");
-	printColor(orig);       
-	printf("\n");
-
-	printf("Ham:\n");
-	printf("Control: %d\n", ham.control);
-	printf("Data: %d\n", ham.data);
-	printf("Color: ");
-	printColor(ham.pixel);
-	printf("\n\n");	
-#endif
-
-	hams[(y*ic->width)+x] = ham;
-    }
-  }
-
-
-  for (int y = 0, writeIndex = 0; y < ic->height; y++) {
-    for (int byte = 0;byte < byteWidth; byte++) {
-      for (int bit = 0; bit < 8; bit++) {	
-	int x = byte * 8 + 7 - bit;    
-
-	ham_control_t ham = hams[(y*ic->width)+x];
-
-	int _numBitPlanes = 4;
-	for (int plane_index = 0; plane_index < _numBitPlanes; plane_index++) {
-	  char* plane = bitplanes[plane_index];
-	  plane[writeIndex] |= ((ham.data >> plane_index) & 1) << bit;
-	}       
-
-	for (int plane_index = 0; plane_index < 2; plane_index++) {
-	  char* plane = bitplanes[4+plane_index];
-	  plane[writeIndex] |= ((ham.control >> plane_index) & 1) << bit;
-	}       
-
-	
-      }
-      writeIndex++;
-    }
-  }
-
-
-  FILE* fp = openFileWrite("%s-ham.bin", outFilename);
-
-  for (int y = 0; y < ic->height; y++) {
-    for (int plane_index = 0; plane_index < numBitPlanes; plane_index++) {
-      char* plane = bitplanes[plane_index];
-      fwrite(&plane[y*byteWidth], byteWidth, 1, fp);      
-    }
-  }
-  fclose(fp);
-  if (config.verbose) {
-    printf("done\n\n");
-  }
-}
-
-static void
-doHamMode(char* outFilename, imagecon_image_t* ic)
-{
-  config.maxColors = 16;
-  generateQuantizedImage(ic, 0);
-
-  if (config.outputBitplanes) {
-    outputHamBitplanes(outFilename, ic);
-  }
-  
-  outputPalette(outFilename, ic);  
-
-}
-
 static void
 processFile(char* outFilename, imagecon_image_t* ic)
 {
@@ -668,21 +316,26 @@ processFile(char* outFilename, imagecon_image_t* ic)
   }
 
   if (config.hamMode) {
-    doHamMode(outFilename, ic);
+    ham_process(outFilename, ic);
   } else { 
     if (config.quantize || config.overridePalette) {
       if (config.ehbMode) {
 	generateEHBImage(ic);
       } else {
 	if (config.overridePalette) {
-	  loadPaletteFile(ic);
+	  palette_loadFile(ic);
 	}
 	generateQuantizedImage(ic, config.overridePalette != 0);
       }
     } else {
-      generatePalette(ic);
+      generatePalettedImage(ic);
     }
-    
+
+    if (config.dither) {
+      dither_image(ic, dither_getPalettedColor);
+      dither_transferToPaletted(ic);    
+    }
+
     if (config.outputBitplanes) {
       outputBitplanes(outFilename, ic);
     }
@@ -691,7 +344,7 @@ processFile(char* outFilename, imagecon_image_t* ic)
       outputMask(outFilename, ic);
     }
     
-    outputPalette(outFilename, ic);
+    palette_output(outFilename, ic);
   }
 
   if (config.verbose) {
@@ -779,6 +432,7 @@ main(int argc, char **argv)
       {"output-mask", no_argument, &config.outputMask, 1},
       {"extra-half-brite", no_argument, &config.ehbMode, 1},
       {"ham", no_argument, &config.hamMode, 1},
+      {"dither", no_argument, &config.dither, 1},
       {"use-palette", required_argument, 0, 'p'},
       {"output",  required_argument, 0, 'o'},
       {"colors",  required_argument, 0, 'c'},
@@ -860,3 +514,5 @@ main(int argc, char **argv)
  
   return 0;
 }
+
+
diff --git a/tools/imagecon/imagecon.h b/tools/imagecon/imagecon.h
index bad5512..713deba 100644
--- a/tools/imagecon/imagecon.h
+++ b/tools/imagecon/imagecon.h
@@ -1,5 +1,16 @@
 #pragma once
 
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <math.h>
+#include <getopt.h>
+#include <libgen.h>
+#include <png.h>
+#include <pngquant/libimagequant.h>
+
 #define MAX_PALETTE 32
 
 typedef struct {
@@ -13,20 +24,13 @@ typedef struct {
   int outputCopperList;
   int ehbMode;
   int hamMode;
+  int dither;
   char* overridePalette;
   int quantize;
   int verbose;
   char** argv;
 } imagecon_config_t;
 
-#if 0
-typedef struct {
-  unsigned char r;
-  unsigned char g;
-  unsigned char b;
-  unsigned char a;
-} amiga_color_t;
-#else
 typedef struct {
   int r;
   int g;
@@ -34,7 +38,11 @@ typedef struct {
   int a;
 } amiga_color_t;
 
-#endif
+typedef struct {
+  int control;
+  int data;
+  amiga_color_t pixel;
+} ham_control_t;
 
 
 typedef struct {
@@ -44,9 +52,23 @@ typedef struct {
   png_bytep* rowPointers;
   unsigned char* amigaImage;
   amiga_color_t palette[MAX_PALETTE*2]; // extra half brite mode
+  amiga_color_t* dithered;
 } imagecon_image_t;
 
 
+#include "color.h"
+#include "dither.h"
+#include "ham.h"
+#include "file.h"
+#include "palette.h"
+
 extern imagecon_config_t config;
-extern void abort_(const char * s, ...);
-extern void png_read(char* file_name, imagecon_image_t* ic);
+
+extern void 
+abort_(const char * s, ...);
+
+extern void 
+png_read(char* file_name, imagecon_image_t* ic);
+
+void
+generateQuantizedImage(imagecon_image_t* ic, int usePalette);
diff --git a/tools/imagecon/palette.c b/tools/imagecon/palette.c
new file mode 100644
index 0000000..b81865d
--- /dev/null
+++ b/tools/imagecon/palette.c
@@ -0,0 +1,103 @@
+#include "imagecon.h"
+
+void palette_loadFile(imagecon_image_t* ic)
+{
+  FILE* fp = file_openRead(config.overridePalette);
+  int paletteIndex;
+  
+  for (paletteIndex = 0; paletteIndex < MAX_PALETTE; paletteIndex++) {
+    unsigned int c;
+    char buffer[255];
+    char* line = fgets(buffer, 255, fp);
+    if (!line) {
+      break;
+    }
+    sscanf(buffer, "%x\n", &c);
+    
+    ic->palette[paletteIndex].r = (c >> 8 & 0xF) << 4;
+    ic->palette[paletteIndex].g = (c >> 4 & 0xF) << 4;
+    ic->palette[paletteIndex].b = (c >> 0 & 0xF) << 4;
+    ic->palette[paletteIndex].a = 255;
+  }
+
+  ic->numColors = paletteIndex;
+}
+
+
+void 
+palette_output(char* outFilename, imagecon_image_t* ic)
+{
+  if (config.verbose) {
+    printf("outputPalette...%d colors\n", ic->numColors);
+  }
+
+  FILE* fp = 0;
+  FILE* paletteFP = 0;
+  FILE* paletteAsmFP = 0;
+  FILE* paletteGreyFP = 0;
+
+  if (config.outputCopperList) {
+    fp = file_openWrite("%s-copper-list.s", outFilename);
+  }
+
+  if (config.outputPalette) {
+    paletteFP = file_openWrite("%s.pal", outFilename);
+  }
+
+  if (config.outputPaletteGrey) {
+    paletteGreyFP = file_openWrite("%s-grey.s", outFilename);
+    fprintf(paletteGreyFP, "\tmovem.l d0-a6,-(sp)\n\tlea CUSTOM,a6\n");
+  }
+
+  if (config.outputPaletteAsm) {
+    paletteAsmFP = file_openWrite("%s-palette.s", outFilename);
+    fprintf(paletteAsmFP, "\tmovem.l d0-a6,-(sp)\n\tlea CUSTOM,a6\n");
+  }
+
+  if (config.verbose) {
+    printf("outputPalette:\n");
+  }
+  
+  for (int i = 0; i < (config.ehbMode ? ic->numColors/2 : ic->numColors); i++) {
+    if (config.verbose) {
+      printf("%02d: hex=%03x r=%03d g=%03d b=%03d a=%03d\n", i , ic->palette[i].r << 8 | ic->palette[i].g << 4 | ic->palette[i].b, ic->palette[i].r, ic->palette[i].g, ic->palette[i].b, ic->palette[i].a);
+    }
+    if (paletteFP) {
+      fprintf(paletteFP, "%03x\n",  (ic->palette[i].r >> 4) << 8 | (ic->palette[i].g >>4) << 4 | (ic->palette[i].b >>4));
+    }
+    if (paletteAsmFP) {
+      fprintf(paletteAsmFP, "\tlea COLOR%02d(a6),a0\n\tmove.w #$%03x,(a0)\n", i, (ic->palette[i].r >> 4) << 8 | (ic->palette[i].g >>4) << 4 | (ic->palette[i].b >>4));
+    }
+    if (paletteGreyFP) {
+      // TODO: this is for compat, can be better
+      unsigned grey = (((ic->palette[i].r>>4) + (ic->palette[i].g>>4) + (ic->palette[i].b>>4))/3);
+      fprintf(paletteGreyFP, "\tlea COLOR%02d(a6),a0\n\tmove.w #$%03x,(a0)\n", i, grey << 8 | grey << 4 | grey);
+    }
+
+    if (fp) {
+      fprintf(fp, "\tdc.w $%x,$%x\n", 0x180+(i*2), (ic->palette[i].r >> 4) << 8 | (ic->palette[i].g >>4) << 4 | (ic->palette[i].b >>4));
+    }
+  }
+
+  if (paletteFP) {
+    fclose(paletteFP);
+  }
+
+  if (paletteGreyFP) {
+    fprintf(paletteGreyFP, "\tmovem.l (sp)+,d0-a6\n");
+    fclose(paletteGreyFP);
+  }
+
+  if (paletteAsmFP) {
+    fprintf(paletteAsmFP, "\tmovem.l (sp)+,d0-a6\n");
+    fclose(paletteFP);
+  }
+
+  if (fp) {
+    fclose(fp);
+  }
+
+  if (config.verbose) {
+    printf("done\n\n");
+  }
+}
diff --git a/tools/imagecon/palette.h b/tools/imagecon/palette.h
new file mode 100644
index 0000000..68a3db7
--- /dev/null
+++ b/tools/imagecon/palette.h
@@ -0,0 +1,7 @@
+#pragma once
+
+void 
+palette_output(char* outFilename, imagecon_image_t* ic);
+
+void 
+palette_loadFile(imagecon_image_t* ic);
diff --git a/tools/imagecon/png.c b/tools/imagecon/png.c
index e52a571..b8cdc63 100644
--- a/tools/imagecon/png.c
+++ b/tools/imagecon/png.c
@@ -117,4 +117,6 @@ png_read(char* file_name, imagecon_image_t* ic)
   }
 
   ic->amigaImage = calloc(ic->width*ic->height, 1);
+
+
 }
diff --git a/tools/imagecon/reference/ham-ham.bin b/tools/imagecon/reference/ham-ham.bin
index f41390a..e50af84 100644
Binary files a/tools/imagecon/reference/ham-ham.bin and b/tools/imagecon/reference/ham-ham.bin differ