Adding optional smoothing capabilities to the tracker

examples/tracking/track_conf.json

 {
   "ball_log_lh": {
     "type": "cb_log_reg",
-    "conf": {  
+    "conf": { 
       "weights": [
         -4.3645153397769523,
         -1.7528550846385467,
@@ -31,7 +31,11 @@
         -5.4301792573145677,
         -4.7388290757015756,
         -5.739125161010926
-      ]
+      ],
+      "gauss_smooth": {
+        "size": 5,
+        "sigma": 0
+      }
     }
   },
   "binarizer": {

src/tracker.cpp

@@ -16,6 +16,23 @@ namespace ball_tracking {
    */
   namespace {
 
+    class GaussSmooth {
+      private:
+        int size;
+        double sigma;
+      public:
+        GaussSmooth(const json& conf) {
+          size = conf.at("size");
+          sigma = conf.at("sigma");
+        }
+
+        cv::Mat operator()(cv::InputArray _src) {
+          Mat dst;
+          GaussianBlur(_src, dst, Size(size,size), sigma, sigma);
+          return dst;
+        }
+    };
+
     /**
      * Color and background based logistic regression
      */
@@ -23,18 +40,32 @@ namespace ball_tracking {
       private:
         Mat bkg; //!< Background image
         Mat weights; //!< Model weights
+        vector<preproc> pre; //!< Preprocessing functions for the images
       public:
-        cv::Mat operator()(cv::InputArray src) {
+ 
+        Mat pre_chain(cv::InputArray src) {
+          Mat tmp = src.getMat();
+          for (auto p : pre) {
+            tmp = p(tmp);
+          }
+          return tmp;
+        }
+ 
+        cv::Mat operator()(cv::InputArray _src) {
+          Mat src = pre_chain(_src);
           if (bkg.empty()) {
-            bkg = src.getMat();
+            bkg = src;
           }
           return quadf_log_reg(src, bkg, weights);
         }
 
         CB_log_reg(const json& conf) {
           weights = json2cvmat(conf.at("weights"));
+          if (conf.count("gauss_smooth")) {
+            pre.push_back(GaussSmooth(conf.at("gauss_smooth")));
+          }
           if (conf.count("background")) {
-            bkg = imread(conf.at("background"), CV_LOAD_IMAGE_COLOR);
+            bkg = pre_chain( imread(conf.at("background"), CV_LOAD_IMAGE_COLOR) );
             if (!bkg.data) {
               throw std::logic_error("File not found for background image");
             }