diff --git a/main.c b/main.c
index 3cc3b68..09a7d2f 100644
--- a/main.c
+++ b/main.c
@@ -9,6 +9,8 @@
 
 #define DEBUG_BUILD 0
 
+#define MASK_VALUE 50000
+
 typedef struct {
     uint32_t    width;
     uint32_t    height;
@@ -16,9 +18,10 @@ typedef struct {
     uint32_t    new_height;
     uint32_t*   buffer;
     uint32_t*   dist_buffer;
+    uint32_t*   mask_buffer;
 } image_T;
 
-uint32_t pixel_distance(uint32_t pixel_a, uint32_t pixel_b) {
+uint32_t pixel_distance(uint32_t pixel_a, uint32_t pixel_b, uint32_t pixel_m) {
     uint8_t r_a = (pixel_a)       & 0xFF;
     uint8_t g_a = (pixel_a >> 8)  & 0xFF;
     uint8_t b_a = (pixel_a >> 16) & 0xFF;
@@ -27,10 +30,14 @@ uint32_t pixel_distance(uint32_t pixel_a, uint32_t pixel_b) {
     uint8_t g_b = (pixel_b >> 8)  & 0xFF;
     uint8_t b_b = (pixel_b >> 16) & 0xFF;
 
+    uint8_t r_m = (pixel_m)       & 0xFF;
+
     uint32_t dist = (uint32_t)sqrt(pow(r_a - r_b, 2) +
                                       pow(g_a - g_b, 2) +
                                       pow(b_a - b_b, 2));
 
+    if (r_m > 0) { dist += MASK_VALUE; }
+
     #if DEBUG_BUILD
         printf("    %x %x %x  --> %x %x %x  =  %d\n", r_a, g_a, b_a, r_b, g_b, b_b, dist);
     #endif
@@ -38,10 +45,11 @@ uint32_t pixel_distance(uint32_t pixel_a, uint32_t pixel_b) {
     return dist;
 }
 
-image_T* image_load(const char* filename) {
+image_T* image_load(const char* filename, const char* filename_mask) {
     printf("loading '%s'...\n", filename);
 
     image_T* image     = malloc(sizeof(image_T));
+    image->mask_buffer = img_load_pixels(filename_mask, (int*)&image->width, (int*)&image->height, IMG_FMT_RGBA32);
     image->buffer      = img_load_pixels(filename, (int*)&image->width, (int*)&image->height, IMG_FMT_RGBA32);
     image->dist_buffer = calloc(image->width * image->height, sizeof(uint32_t));
     image->new_width   = image->width;
@@ -52,6 +60,7 @@ void image_destruct(image_T* image) {
     printf("destructing resources\n");
 
     img_free_pixels(image->buffer);
+    img_free_pixels(image->mask_buffer);
     free(image->dist_buffer);
     free(image);
 }
@@ -77,7 +86,7 @@ void image_calculate_dist_buffer(image_T* image) {
 
             int32_t shortest_dist = -1;
             for (int i = (x > 0 ? -1 : 0); i < (x < image->new_width-1 ? 2 : 1); i++) {
-                uint32_t dist = pixel_distance(pixel, last_row[x + i]) + dist_last_row[x + i];
+                uint32_t dist = pixel_distance(pixel, last_row[x + i], image->mask_buffer[(y * image->width) + x + i]) + dist_last_row[x + i];
 
                 if (shortest_dist == -1 || shortest_dist > dist) {
                     shortest_dist = (int32_t)dist;
@@ -110,7 +119,6 @@ uint32_t image_find_best_line(image_T* image) {
         if (shortest_dist == -1 || shortest_dist > row[x]) {
             shortest_dist = (int32_t)row[x];
             line_id       = x;
-            printf("id: %d  dist: %d\n", x, row[x]);
         }
     }
 
@@ -133,11 +141,13 @@ void image_cut_line(image_T* image, uint32_t line_id) {
         }
         x += offset;
         memcpy(&image->buffer[(image->width * y) + x], &image->buffer[(image->width * y) + x + 1], (image->new_width - x) * sizeof(uint32_t));
+        memcpy(&image->mask_buffer[(image->width * y) + x], &image->mask_buffer[(image->width * y) + x + 1], (image->new_width - x) * sizeof(uint32_t));
         gfx_color(0, 0xFF, 0);
         gfx_point(x, y);
-        gfx_flush();
     }
     image->new_width -= 1;
+
+    gfx_flush();
 }
 
 void image_dump(image_T* image) {
@@ -166,7 +176,7 @@ void image_dump(image_T* image) {
     }
 
     gfx_color(0, 0, 0);
-    for (int y = 0; y < image->new_height; y++) {
+    for (int y = 0; y < image->new_height*2; y++) {
         gfx_point(image->new_width, y);
     }
 
@@ -196,14 +206,15 @@ void image_dump(image_T* image) {
 int main() {
     printf("Line Cutter - Juniorcamp Informatik\n");
 
-    image_T* image = image_load("../paris.png");
+    image_T* image = image_load("../paris.png", "../paris_mask.png");
 
     gfx_open(800, 600, "Juniorcamp Informatik - Line Cutter");
+    image_dump(image);
 
     bool running = true;
     while(running) {
-        image_dump(image);
         char c = gfx_wait();
+        image_dump(image);
         switch (c) {
             case 's': {
                 image_calculate_dist_buffer(image);
diff --git a/paris_mask.png b/paris_mask.png
new file mode 100644
index 0000000..16ecf93
Binary files /dev/null and b/paris_mask.png differ