From 3003bf5338e4c7962248e943ba3ece1482a96879 Mon Sep 17 00:00:00 2001
From: Jim Martens <github@2martens.de>
Date: Sun, 7 May 2017 15:49:07 +0200
Subject: [PATCH] [CCV] Added across scale addition method

Signed-off-by: Jim Martens <github@2martens>
---
 ccv/sheet4/lab_pyramid.cpp | 11 +++++++++++
 ccv/sheet4/lab_pyramid.h   |  8 ++++++++
 2 files changed, 19 insertions(+)

diff --git a/ccv/sheet4/lab_pyramid.cpp b/ccv/sheet4/lab_pyramid.cpp
index c21e384..0653121 100644
--- a/ccv/sheet4/lab_pyramid.cpp
+++ b/ccv/sheet4/lab_pyramid.cpp
@@ -96,6 +96,17 @@ void lab_pyramid::compute_dog(lab_pyramid center, lab_pyramid surround, int numb
   }
 }
 
+cv::Mat lab_pyramid::across_scale_addition(const std::vector<cv::Mat> &scale_images) {
+  cv::Mat result = scale_images.front();
+  cv::Size original_size = scale_images.front().size();
+  for (unsigned long i = 1; i < scale_images.size(); i++) {
+    cv::Mat resized_image;
+    cv::resize(scale_images.at(i), resized_image, original_size, 0, 0, cv::INTER_CUBIC);
+    result += resized_image;
+  }
+  return result;
+}
+
 void lab_pyramid::visualize_dog() {
   for (unsigned long layer = 0; layer < _number_of_layers; layer++) {
     cv::namedWindow("CS L");
diff --git a/ccv/sheet4/lab_pyramid.h b/ccv/sheet4/lab_pyramid.h
index 0ae957d..247201d 100644
--- a/ccv/sheet4/lab_pyramid.h
+++ b/ccv/sheet4/lab_pyramid.h
@@ -61,6 +61,14 @@ public:
      */
     void static compute_dog(lab_pyramid center, lab_pyramid surround, int number_of_layers);
 
+    /**
+     * Takes the scale images, adds them up and returns the result.
+     *
+     * @param scale_images the scale images
+     * @return the sum of the scale images
+     */
+    cv::Mat static across_scale_addition(const std::vector<cv::Mat>& scale_images);
+
     /**
      * Visualizes the center-surround and surround-center contrasts. They have to be computed first.
      */