Add acf feature evaluator interface

apps/icf/acffeature.hpp

+/*
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+*/
+
+#ifndef __OPENCV_ADAS_ACFFEATURE_HPP__
+#define __OPENCV_ADAS_ACFFEATURE_HPP__
+
+namespace cv
+{
+namespace adas
+{
+
+/* Compute channel pyramid for acf features
+
+    image — image, for which pyramid should be computed
+
+    params — pyramid computing parameters
+
+Returns computed channels in vectors N x CH,
+N — number of scales (outer vector),
+CH — number of channels (inner vectors)
+*/
+std::vector<Mat>
+computeChannels(const Mat& image);
+
+class ACFFeatureEvaluator
+{
+public:
+    /* Construct evaluator, set features to evaluate */
+    ACFFeatureEvaluator(const std::vector<Point>& features);
+
+    /* Set channels for feature evaluation */
+    void setChannels(const std::vector<Mat> >& channels);
+
+    /* Set window position */
+    void setPosition(Size position);
+
+    /* Evaluate feature with given index for current channels
+        and window position */
+    int evaluate(size_t feature_ind) const;
+
+    /* Evaluate all features for current channels and window position
+
+    Returns matrix-column of features
+    */
+    Mat evaluateAll() const;
+
+private:
+    /* Features to evaluate */
+    std::vector<Point> features_;
+    /* Channels for feature evaluation */
+    std::vector<Mat> channels;
+    /* Channels window position */
+    Size position_;
+};
+
+/* Generate acf features
+
+    window_size — size of window in which features should be evaluated
+
+    count — number of features to generate.
+    Max number of features is min(count, # possible distinct features)
+
+    seed — random number generator initializer
+
+Returns vector of distinct acf features
+*/
+std::vector<Point>
+generateFeatures(Size window_size, size_t count = UINT_MAX, int seed = 0);
+
+} /* namespace adas */
+} /* namespace cv */
+
+#endif /* __OPENCV_ADAS_ACFFEATURE_HPP__ */