From 4de6090ab9e0442f6f51c45e52ccab875eeb0ce9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Colin=20de=20Verdi=C3=A8re?=
 <francois.cdverdiere@gmail.com>
Date: Tue, 1 Apr 2025 17:01:53 +0200
Subject: [PATCH] does not recompute energy for horizontal seams too

---
 src/seam-carving.cpp | 59 +++++++++++++++++++++++---------------------
 1 file changed, 31 insertions(+), 28 deletions(-)

diff --git a/src/seam-carving.cpp b/src/seam-carving.cpp
index 1c90c7a..04fa366 100644
--- a/src/seam-carving.cpp
+++ b/src/seam-carving.cpp
@@ -181,7 +181,8 @@ std::vector<int> carving_step(const std::vector<unsigned char> source_img,
                               std::vector<float> source_energy,
                               std::vector<unsigned char> &output_img,
                               std::vector<float> &output_energy, int width,
-                              int height, int nbChannels, bool vertical) {
+                              int height, int nbChannels, int nbColorChannels,
+                              bool vertical) {
   /** Carves an image and its energy by one seam, and recomputes the energy.
       Returns the optimal seam used */
   std::vector<int> opt_seam =
@@ -199,20 +200,29 @@ std::vector<int> carving_step(const std::vector<unsigned char> source_img,
                   vertical ? height : height - 1, nbChannels);
     std::copy(energy.begin(), energy.end(), output_energy.begin());
   } else {
-    int nbColorChannels = 3;
 
-    std::cout << "starting to recompute the energy along the seam" << std::endl;
     // ASSUME WE ARE DOING A VERTICAL SEAM
-    for (auto j = 0; j < height; j++) {
-      for (auto i = -1; i < 2; i++) {
-        if ((0 < (opt_seam[j] + i)) && ((opt_seam[j] + i) < width)) {
-          compute_energy_for_pixel(output_img, (width - 1), height,
-                                   (opt_seam[j] + i), j, nbChannels,
-                                   nbColorChannels, output_energy);
+    if (vertical) {
+      for (auto j = 0; j < height; j++) {
+        for (auto i = -1; i < 2; i++) {
+          if ((0 < (opt_seam[j] + i)) && ((opt_seam[j] + i) < width - 1)) {
+            compute_energy_for_pixel(output_img, (width - 1), height,
+                                     (opt_seam[j] + i), j, nbChannels,
+                                     nbColorChannels, output_energy);
+          }
+        }
+      }
+    } else {
+      for (auto i = 0; i < width; i++) {
+        for (auto j = -1; j < 2; j++) {
+          if ((0 < (opt_seam[i] + j)) && ((opt_seam[i] + j) < height - 1)) {
+            compute_energy_for_pixel(output_img, width, height - 1, i,
+                                     (opt_seam[i] + j), nbChannels,
+                                     nbColorChannels, output_energy);
+          }
         }
       }
     }
-    std::cout << "DONE" << std::endl;
   }
   return opt_seam;
 }
@@ -257,13 +267,13 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
 
     //* Prepare final output
 
-    float max_energy=__FLT_MAX__;
-    for (auto k=0;k<width*height;k++){
-      max_energy=fmax(max_energy, ini_energy[k]);
+    float max_energy = __FLT_MAX__;
+    for (auto k = 0; k < width * height; k++) {
+      max_energy = fmax(max_energy, ini_energy[k]);
     }
-    if (max_energy!=0){
-      for (auto k=0;k<width*height;k++){
-	ini_energy[k]/=max_energy;
+    if (max_energy != 0) {
+      for (auto k = 0; k < width * height; k++) {
+        ini_energy[k] /= max_energy;
       }
     }
     for (auto k = 0; k < width * height; k++) {
@@ -281,19 +291,15 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
 
   SimpleProgressBar::ProgressBar bar(nbSeams);
   for (auto seam_index = 0; seam_index < nbSeams; seam_index++) {
-    std::vector<int> opt_seam =
-        carving_step(source_img, source_energy, output_img, output_energy,
-                     curWidth, curHeight, nbChannels, vertical);
+    std::vector<int> opt_seam = carving_step(
+        source_img, source_energy, output_img, output_energy, curWidth,
+        curHeight, nbChannels, nbColorChannels, vertical);
     std::copy(output_img.begin(), output_img.end(), source_img.begin());
     std::copy(output_energy.begin(), output_energy.end(),
               source_energy.begin());
 
-    if (vertical) // We just reduced the dimension
-      curWidth--;
-    else
-      curHeight--;
-
-    if (test_energy) { // Update blacklist
+    vertical ? curWidth-- : curHeight--; // We just reduced the dimension
+    if (test_energy) {                   // Update blacklist
 
       for (auto i = 0; i < dim_long; i++) {
         int j, cur_j = 0; // cur_j is the index relative to the current carved
@@ -305,17 +311,14 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
         }
         assert(cur_j == opt_seam[i]); // Else, j == width and cur_j is not in
                                       // the source image..
-
         complete_blacklist[im_index(i, j)] = true;
         test_energy_output[nbChannels * im_index(i, j)] =
             255; // Set carved pixel to red
       }
     }
-
     bar.increment();
     bar.print();
   }
-  // std::cout << std::endl;
 
   if (test_energy) {
     export_image(out_filename, test_energy_output.data(), width, height,