diff --git a/app/src/main/cpp/hdrplus/src/align.cpp b/app/src/main/cpp/hdrplus/src/align.cpp
index 98f6eb88..cc2d9219 100644
--- a/app/src/main/cpp/hdrplus/src/align.cpp
+++ b/app/src/main/cpp/hdrplus/src/align.cpp
@@ -933,6 +933,8 @@ void align::process( const hdrplus::burst& burst_images, \
 
     // Align every image
     const std::vector<cv::Mat>& ref_grayimg_pyramid = per_grayimg_pyramid[ burst_images.reference_image_idx ];
+    std::vector<std::vector<std::pair<int, int>>> curr_alignment;
+    std::vector<std::vector<std::pair<int, int>>> prev_alignment;
     for ( int img_idx = 0; img_idx < burst_images.num_images; ++img_idx )
     {
         // Do not align with reference image
@@ -944,8 +946,8 @@ void align::process( const hdrplus::burst& burst_images, \
         // Align every level from coarse to grain
         // level 0 : finest level, the original image
         // level 3 : coarsest level
-        std::vector<std::vector<std::pair<int, int>>> curr_alignment;
-        std::vector<std::vector<std::pair<int, int>>> prev_alignment;
+        curr_alignment.clear();
+        prev_alignment.clear();
         for ( int level_i = num_levels - 1; level_i >= 0; level_i-- ) // 3,2,1,0
         {
             // make curr alignment as previous alignment
diff --git a/app/src/main/cpp/hdrplus/src/hdrplus_pipeline.cpp b/app/src/main/cpp/hdrplus/src/hdrplus_pipeline.cpp
index 3cf00719..2ba525c7 100644
--- a/app/src/main/cpp/hdrplus/src/hdrplus_pipeline.cpp
+++ b/app/src/main/cpp/hdrplus/src/hdrplus_pipeline.cpp
@@ -10,6 +10,10 @@
 #include "hdrplus/finish.h"
 #include <fstream>
 
+#ifdef __ANDROID__
+#include <AndroidHelper.h>
+#endif
+
 namespace hdrplus
 {
 
@@ -19,6 +23,7 @@ void hdrplus_pipeline::run_pipeline( \
 {
     // Create burst of images
     burst burst_images( burst_path, reference_image_path );
+
     std::vector<std::vector<std::vector<std::pair<int, int>>>> alignments;
 
     // Run align
@@ -27,6 +32,7 @@ void hdrplus_pipeline::run_pipeline( \
     // Run merging
     merge_module.process( burst_images, alignments );
 
+
     // Run finishing
     cv::Mat finalImg;
     finish_module.process( burst_images, finalImg);
@@ -39,15 +45,27 @@ bool hdrplus_pipeline::run_pipeline( \
     // Create burst of images
     burst burst_images( burst_paths, reference_image_index );
     std::vector<std::vector<std::vector<std::pair<int, int>>>> alignments;
+#ifdef __ANDROID__
+    ALOGI("Finish loading images");
+#endif
 
     // Run align
     align_module.process( burst_images, alignments );
+#ifdef __ANDROID__
+    ALOGI("Finish align");
+#endif
 
     // Run merging
     merge_module.process( burst_images, alignments );
+#ifdef __ANDROID__
+    ALOGI("Finish merging");
+#endif
 
     // Run finishing
     finish_module.process( burst_images, finalImg);
+#ifdef __ANDROID__
+    ALOGI("Finish process");
+#endif
 
     return true;
 }
diff --git a/app/src/main/cpp/hdrplus/src/merge.cpp b/app/src/main/cpp/hdrplus/src/merge.cpp
index 5e0de3b5..bdf5c400 100644
--- a/app/src/main/cpp/hdrplus/src/merge.cpp
+++ b/app/src/main/cpp/hdrplus/src/merge.cpp
@@ -116,8 +116,9 @@ namespace hdrplus
         // 1. get all four subsets: original (evenly split), horizontal overlapped,
         // vertical overlapped, 2D overlapped
         std::vector<std::vector<cv::Mat>> tiles_original;
+        std::vector<cv::Mat> row;
         for (int y = 0; y < num_rows / offset - 1; y += 2) {
-            std::vector<cv::Mat> row;
+            row.clear();
             for (int x = 0; x < num_cols / offset - 1; x += 2) {
                 row.push_back(tiles[y * (num_cols / offset - 1) + x]);
             }
@@ -125,8 +126,9 @@ namespace hdrplus
         }
 
         std::vector<std::vector<cv::Mat>> tiles_horizontal;
+        // std::vector<cv::Mat> row;
         for (int y = 0; y < num_rows / offset - 1; y += 2) {
-            std::vector<cv::Mat> row;
+            row.clear();
             for (int x = 1; x < num_cols / offset - 1; x += 2) {
                 row.push_back(tiles[y * (num_cols / offset - 1) + x]);
             }
@@ -134,8 +136,9 @@ namespace hdrplus
         }
 
         std::vector<std::vector<cv::Mat>> tiles_vertical;
+        // std::vector<cv::Mat> row;
         for (int y = 1; y < num_rows / offset - 1; y += 2) {
-            std::vector<cv::Mat> row;
+            row.clear();
             for (int x = 0; x < num_cols / offset - 1; x += 2) {
                 row.push_back(tiles[y * (num_cols / offset - 1) + x]);
             }
@@ -143,8 +146,9 @@ namespace hdrplus
         }
 
         std::vector<std::vector<cv::Mat>> tiles_2d;
+        // std::vector<cv::Mat> row;
         for (int y = 1; y < num_rows / offset - 1; y += 2) {
-            std::vector<cv::Mat> row;
+            row.clear();
             for (int x = 1; x < num_cols / offset - 1; x += 2) {
                 row.push_back(tiles[y * (num_cols / offset - 1) + x]);
             }
@@ -190,9 +194,10 @@ namespace hdrplus
         std::vector<std::vector<cv::Mat>> alt_tiles_list(reference_tiles.size());
         int num_tiles_row = alternate_channel_i_list[0].rows / offset - 1;
         int num_tiles_col = alternate_channel_i_list[0].cols / offset - 1;
+        std::vector<cv::Mat> alt_tiles;
         for (int y = 0; y < num_tiles_row; ++y) {
             for (int x = 0; x < num_tiles_col; ++x) {
-                std::vector<cv::Mat> alt_tiles;
+                alt_tiles.clear();
                 // Get reference tile location
                 int top_left_y = y * offset;
                 int top_left_x = x * offset;