doc/tutorials/features2d/feature_description/feature_description.markdown

   1 Feature Description {#tutorial_feature_description}
   2 ===================
   3
   4 @prev_tutorial{tutorial_feature_detection}
   5 @next_tutorial{tutorial_feature_flann_matcher}
   6
   7 Goal
   8 ----
   9
  10 In this tutorial you will learn how to:
  11
  12 -   Use the @ref cv::DescriptorExtractor interface in order to find the feature vector correspondent
  13     to the keypoints. Specifically:
  14     -   Use cv::xfeatures2d::SURF and its function cv::xfeatures2d::SURF::compute to perform the
  15         required calculations.
  16     -   Use a @ref cv::DescriptorMatcher to match the features vector
  17     -   Use the function @ref cv::drawMatches to draw the detected matches.
  18
  19 \warning You need the <a href="https://github.com/opencv/opencv_contrib">OpenCV contrib modules</a> to be able to use the SURF features
  20 (alternatives are ORB, KAZE, ... features).
  21
  22 Theory
  23 ------
  24
  25 Code
  26 ----
  27
  28 @add_toggle_cpp
  29 This tutorial code's is shown lines below. You can also download it from
  30 [here](https://github.com/opencv/opencv/tree/3.4/samples/cpp/tutorial_code/features2D/feature_description/SURF_matching_Demo.cpp)
  31 @include samples/cpp/tutorial_code/features2D/feature_description/SURF_matching_Demo.cpp
  32 @end_toggle
  33
  34 @add_toggle_java
  35 This tutorial code's is shown lines below. You can also download it from
  36 [here](https://github.com/opencv/opencv/tree/3.4/samples/java/tutorial_code/features2D/feature_description/SURFMatchingDemo.java)
  37 @include samples/java/tutorial_code/features2D/feature_description/SURFMatchingDemo.java
  38 @end_toggle
  39
  40 @add_toggle_python
  41 This tutorial code's is shown lines below. You can also download it from
  42 [here](https://github.com/opencv/opencv/tree/3.4/samples/python/tutorial_code/features2D/feature_description/SURF_matching_Demo.py)
  43 @include samples/python/tutorial_code/features2D/feature_description/SURF_matching_Demo.py
  44 @end_toggle
  45
  46 Explanation
  47 -----------
  48
  49 Result
  50 ------
  51
  52 Here is the result after applying the BruteForce matcher between the two original images:
  53
  54 ![](images/Feature_Description_BruteForce_Result.jpg)