From 5b50d63754bade8ffa0109be75fb3300318561d0 Mon Sep 17 00:00:00 2001
From: Alexey Spizhevoy <no@email>
Date: Fri, 20 May 2011 07:44:37 +0000
Subject: [PATCH] added number of bands estimation in opencv_stitching

---
 modules/stitching/blenders.hpp | 3 +++
 modules/stitching/main.cpp     | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/modules/stitching/blenders.hpp b/modules/stitching/blenders.hpp
index ae1b6b3716..308a81f8c6 100644
--- a/modules/stitching/blenders.hpp
+++ b/modules/stitching/blenders.hpp
@@ -41,6 +41,9 @@ class MultiBandBlender : public Blender
 public:
     MultiBandBlender(int num_bands = 7) : num_bands_(num_bands) {}
 
+    int numBands() const { return num_bands_; }
+    void setNumBands(int val) { num_bands_ = val; }
+
 private:
     cv::Point blend(const std::vector<cv::Mat> &src, const std::vector<cv::Point> &corners, const std::vector<cv::Mat> &masks,
                     cv::Mat& dst, cv::Mat& dst_mask);
diff --git a/modules/stitching/main.cpp b/modules/stitching/main.cpp
index 579cfdb2cc..996ce65121 100644
--- a/modules/stitching/main.cpp
+++ b/modules/stitching/main.cpp
@@ -347,8 +347,13 @@ int main(int argc, char* argv[])
 
     t = getTickCount();
     LOGLN("Blending images...");
-    Mat result, result_mask;
     Ptr<Blender> blender = Blender::createDefault(blend_type);
+    if (blend_type == Blender::MULTI_BAND)
+        // Ensure last pyramid layer area is about 1 pix 
+        dynamic_cast<MultiBandBlender*>((Blender*)(blender))
+            ->setNumBands(static_cast<int>(ceil(log(static_cast<double>(images_f[0].size().area())) 
+                                                / log(4.0))));
+    Mat result, result_mask;
     (*blender)(images_f, corners, masks_warped, result, result_mask);
     LOGLN("Blending images, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec");