Derive WaldBoost from Algorithm

modules/xobjdetect/include/opencv2/xobjdetect.hpp

@@ -108,56 +108,10 @@ struct CV_EXPORTS WaldBoostParams
 };
 
 
-class CV_EXPORTS Stump
-{
-public:
-
-    /* Initialize zero stump */
-    Stump(): threshold_(0), polarity_(1), pos_value_(1), neg_value_(-1) {}
-
-    /* Initialize stump with given threshold, polarity
-        and classification values */
-    Stump(int threshold, int polarity, float pos_value, float neg_value):
-        threshold_(threshold), polarity_(polarity),
-        pos_value_(pos_value), neg_value_(neg_value) {}
-
-    /* Train stump for given data
-
-        data — matrix of feature values, size M x N, one feature per row
-
-        labels — matrix of sample class labels, size 1 x N. Labels can be from
-            {-1, +1}
-
-        weights — matrix of sample weights, size 1 x N
-
-    Returns chosen feature index. Feature enumeration starts from 0
-    */
-    int train(const Mat& data, const Mat& labels, const Mat& weights);
-
-    /* Predict object class given
-
-        value — feature value. Feature must be the same as was chosen
-        during training stump
-
-    Returns real value, sign(value) means class
-    */
-    float predict(int value) const;
-
-private:
-    /* Stump decision threshold */
-    int threshold_;
-    /* Stump polarity, can be from {-1, +1} */
-    int polarity_;
-    /* Classification values for positive and negative classes  */
-    float pos_value_, neg_value_;
-};
 
 class CV_EXPORTS WaldBoost : public Algorithm
 {
 public:
-    /* Initialize WaldBoost cascade with default of specified parameters */
-    WaldBoost(const WaldBoostParams& params = WaldBoostParams());
-
     /* Train WaldBoost cascade for given data
 
         data — matrix of feature values, size M x N, one feature per row
@@ -168,8 +122,8 @@ public:
     Returns feature indices chosen for cascade.
     Feature enumeration starts from 0
     */
-    std::vector<int> train(const Mat& data,
-                           const Mat& labels);
+    virtual std::vector<int> train(const Mat& data,
+                                   const Mat& labels) = 0;
 
     /* Predict object class given object that can compute object features
 
@@ -178,17 +132,14 @@ public:
     Returns confidence_value — measure of confidense that object
     is from class +1
     */
-    float predict(const Ptr<ACFFeatureEvaluator>& feature_evaluator);
+    virtual float predict(
+        const Ptr<ACFFeatureEvaluator>& feature_evaluator) const = 0;
 
-private:
-    /* Parameters for cascade training */
-    WaldBoostParams params_;
-    /* Stumps in cascade */
-    std::vector<Stump> stumps_;
-    /* Rejection thresholds for linear combination at every stump evaluation */
-    std::vector<float> thresholds_;
 };
 
+CV_EXPORTS Ptr<WaldBoost>
+createWaldBoost(const WaldBoostParams& params = WaldBoostParams());
+
 struct CV_EXPORTS ICFDetectorParams
 {
     int feature_count;

modules/xobjdetect/src/icfdetector.cpp

@@ -137,8 +137,8 @@ void ICFDetector::train(const vector<string>& image_filenames,
     wparams.weak_count = params.weak_count;
     wparams.alpha = 0.001f;
 
-    WaldBoost waldboost(wparams);
-    waldboost.train(data, labels);
+    Ptr<WaldBoost> waldboost = createWaldBoost(wparams);
+    waldboost->train(data, labels);
 }
 
 bool ICFDetector::save(const string&)

modules/xobjdetect/src/precomp.hpp

@@ -43,6 +43,7 @@ the use of this software, even if advised of the possibility of such damage.
 #define __OPENCV_XOBJDETECT_PRECOMP_HPP__
 
 #include <opencv2/xobjdetect.hpp>
+#include <opencv2/xobjdetect/private.hpp>
 
 #include <opencv2/imgproc.hpp>
 #include <opencv2/imgproc/types_c.h>

modules/xobjdetect/src/waldboost.cpp

@@ -41,7 +41,6 @@ the use of this software, even if advised of the possibility of such damage.
 
 #include "precomp.hpp"
 
-
 using std::swap;
 
 using std::vector;
@@ -51,11 +50,30 @@ namespace cv
 namespace xobjdetect
 {
 
-WaldBoost::WaldBoost(const WaldBoostParams& params): params_(params)
+class WaldBoostImpl : public WaldBoost
 {
-}
+public:
+    /* Initialize WaldBoost cascade with default of specified parameters */
+    WaldBoostImpl(const WaldBoostParams& params):
+        params_(params)
+    {}
 
-vector<int> WaldBoost::train(const Mat& data, const Mat& labels)
+    virtual std::vector<int> train(const Mat& data,
+                                   const Mat& labels);
+
+    virtual float predict(
+        const Ptr<ACFFeatureEvaluator>& feature_evaluator) const;
+
+private:
+    /* Parameters for cascade training */
+    WaldBoostParams params_;
+    /* Stumps in cascade */
+    std::vector<Stump> stumps_;
+    /* Rejection thresholds for linear combination at every stump evaluation */
+    std::vector<float> thresholds_;
+};
+
+vector<int> WaldBoostImpl::train(const Mat& data, const Mat& labels)
 {
     CV_Assert(labels.rows == 1 && labels.cols == data.cols);
 
@@ -144,7 +162,8 @@ vector<int> WaldBoost::train(const Mat& data, const Mat& labels)
     return feature_indices;
 }
 
-float WaldBoost::predict(const Ptr<ACFFeatureEvaluator>& feature_evaluator)
+float WaldBoostImpl::predict(
+    const Ptr<ACFFeatureEvaluator>& feature_evaluator) const
 {
     float trace = 0;
     for( size_t i = 0; i < stumps_.size(); ++i )
@@ -157,5 +176,12 @@ float WaldBoost::predict(const Ptr<ACFFeatureEvaluator>& feature_evaluator)
     return trace;
 }
 
+Ptr<WaldBoost>
+createWaldBoost(const WaldBoostParams& params)
+{
+    return Ptr<WaldBoost>(new WaldBoostImpl(params));
+}
+
+
 } /* namespace xobjdetect */
 } /* namespace cv */