Set energy to {0, 0.} for negatively-masked pixels

src/seam-carving.cpp

@@ -37,7 +37,7 @@ void export_image(const char *filename, const void *data, int width, int height,
 #define compute_energy_for_pixel(                                              \
     source, width, height, i, j,                                               \
     nbChannels, /* computes the energy at pixel i,j, i.e. energy[width*j+i]*/  \
-    nbColorChannels, dest)                                                     \
+    nbColorChannels, dest) {                                                   \
   auto indexPixel = (nbChannels) * (width * (j) + (i));                        \
   auto indexPixel_up =                                                         \
       ((j) - 1 > 0) ? (nbChannels) * (width * ((j) - 1) + (i)) : indexPixel;   \
@@ -132,7 +132,7 @@ void export_image(const char *filename, const void *data, int width, int height,
     std::cerr << "no implementation found for function \"" << function << "\"" \
               << std::endl;                                                    \
     exit(1);                                                                   \
-  };
+  }}
 
 
 
@@ -324,9 +324,11 @@ void recompute_energy_along_seam(
         int y = vertical ? j0 + j_offset : (i0 + i_offset);
         if (((0 < (i0 + i_offset)) && ((i0 + i_offset) < dim_large - 1)) &&
             (((0 < j0 + j_offset) && (j0 + j_offset < dim_long)))) {
-          compute_energy_for_pixel(carved_img, newWidth, newHeight, x, y,
-                                   nbChannels, nbColorChannels,
-                                   output_energy[width * y + x].second);
+          // if the pixel is to be removed, we keep the energy at 0.
+          if (output_energy[width * y + x].first != 0)
+            compute_energy_for_pixel(carved_img, newWidth, newHeight, x, y,
+                                    nbChannels, nbColorChannels,
+                                    output_energy[width * y + x].second);
         }
       }
     }

src/utils.cpp

@@ -32,6 +32,9 @@ std::vector<std::pair<int, float>> mask_energy(std::vector<float> energy,
   std::vector<std::pair<int, float>> output(width*height);
 
   for (auto i=0; i < width*height; i++) {
+    if (mask[i] == 0) // We want to remove the pixel
+      energy[i] = 0.;
+
     output[i] = {mask[i], energy[i]};
   }