diff --git a/src/merge.cpp b/src/merge.cpp
index b0f612e..e296690 100644
--- a/src/merge.cpp
+++ b/src/merge.cpp
@@ -379,27 +379,95 @@ std::pair<double, double> merge::getNoiseParams( int ISO, \
     double lambda_shot, lambda_read;
     std::tie(lambda_shot, lambda_read) = burst_images.bayer_images[burst_images.reference_image_idx].get_noise_params();
 
-    // Obtain tiles
-    cv::Mat reference_image = burst_images.grayscale_images_pad[0];
+    // Obtain Reference tiles
+    cv::Mat reference_image = burst_images.grayscale_images_pad[burst_images.reference_image_idx];
     std::vector<cv::Mat> reference_tiles = getReferenceTiles(reference_image);
 
+    // Temporal Denoising
+
+    // Spatial Denoising
+
+    // Process tiles through 2D cosine window
+    std::vector<cv::Mat> windowed_tiles;
+    for (auto tile : reference_tiles) {
+        windowed_tiles.push_back(cosineWindow2D(tile));
+    }
+
+    // Merge tiles
+    cv::Mat merged = mergeTiles(windowed_tiles, reference_image.rows, reference_image.cols);
+
     // cv::Mat outputImg = reference_image.clone();
     // cv::cvtColor(outputImg, outputImg, cv::COLOR_GRAY2RGB);
     // cv::imwrite("ref.jpg", outputImg);
+    // cv::Mat outputImg1 = reference_tiles[0].clone();
     // cv::Mat outputImg1 = cosineWindow2D(reference_tiles[0].clone());
+    // cv::Mat outputImg1 = cat2Dtiles(tiles_2D);
     // cv::cvtColor(outputImg1, outputImg1, cv::COLOR_GRAY2RGB);
     // cv::imwrite("tile0.jpg", outputImg1);
 }
 
 std::vector<cv::Mat> merge::getReferenceTiles(cv::Mat reference_image) {
     std::vector<cv::Mat> reference_tiles;
-    for (int y = 0; y < reference_image.rows - 8; y += 8) {
-        for (int x = 0; x < reference_image.cols - 8; x += 8) {
-            cv::Mat tile = reference_image(cv::Rect(x, y, 16, 16));
+    for (int y = 0; y < reference_image.rows - offset; y += offset) {
+        for (int x = 0; x < reference_image.cols - offset; x += offset) {
+            cv::Mat tile = reference_image(cv::Rect(x, y, TILE_SIZE, TILE_SIZE));
             reference_tiles.push_back(tile);
         }
     }
     return reference_tiles;
 }
 
+cv::Mat merge::mergeTiles(std::vector<cv::Mat> tiles, int num_rows, int num_cols){
+    // 1. get all four subsets: original (evenly split), horizontal overlapped,
+    // vertical overlapped, 2D overlapped
+    std::vector<std::vector<cv::Mat>> tiles_original;
+    for (int y = 0; y < num_rows / offset - 1; y += 2) {
+        std::vector<cv::Mat> row;
+        for (int x = 0; x < num_cols / offset - 1; x += 2) {
+            row.push_back(tiles[y * (num_cols / offset - 1) + x]);
+        }
+        tiles_original.push_back(row);
+    }
+
+    std::vector<std::vector<cv::Mat>> tiles_horizontal;
+    for (int y = 0; y < num_rows / offset - 1; y += 2) {
+        std::vector<cv::Mat> row;
+        for (int x = 1; x < num_cols / offset - 1; x += 2) {
+            row.push_back(tiles[y * (num_cols / offset - 1) + x]);
+        }
+        tiles_horizontal.push_back(row);
+    }
+
+    std::vector<std::vector<cv::Mat>> tiles_vertical;
+    for (int y = 1; y < num_rows / offset - 1; y += 2) {
+        std::vector<cv::Mat> row;
+        for (int x = 0; x < num_cols / offset - 1; x += 2) {
+            row.push_back(tiles[y * (num_cols / offset - 1) + x]);
+        }
+        tiles_vertical.push_back(row);
+    }
+
+    std::vector<std::vector<cv::Mat>> tiles_2d;
+    for (int y = 1; y < num_rows / offset - 1; y += 2) {
+        std::vector<cv::Mat> row;
+        for (int x = 1; x < num_cols / offset - 1; x += 2) {
+            row.push_back(tiles[y * (num_cols / offset - 1) + x]);
+        }
+        tiles_2d.push_back(row);
+    }
+
+    // 2. Concatenate the four subsets
+    cv::Mat img_original = cat2Dtiles(tiles_original);
+    cv::Mat img_horizontal = cat2Dtiles(tiles_horizontal);
+    cv::Mat img_vertical = cat2Dtiles(tiles_vertical);
+    cv::Mat img_2d = cat2Dtiles(tiles_2d);
+
+    // 3. Add the four subsets together
+    img_original(cv::Rect(offset, 0, num_cols - TILE_SIZE, num_rows)) += img_horizontal;
+    img_original(cv::Rect(0, offset, num_cols, num_rows - TILE_SIZE)) += img_vertical;
+    img_original(cv::Rect(offset, offset, num_cols - TILE_SIZE, num_rows - TILE_SIZE)) += img_2d;
+
+    return img_original;
+}
+
 } // namespace hdrplus