opencv/doc/tutorials/features2d/feature_homography/feature_homography.markdown

59 lines
2.1 KiB
Markdown
Raw Normal View History

2014-11-27 20:39:05 +08:00
Features2D + Homography to find a known object {#tutorial_feature_homography}
==============================================
2020-12-08 00:13:54 +08:00
@tableofcontents
@prev_tutorial{tutorial_feature_flann_matcher}
@next_tutorial{tutorial_detection_of_planar_objects}
2020-12-05 06:46:00 +08:00
| | |
| -: | :- |
| Original author | Ana Huamán |
| Compatibility | OpenCV >= 3.0 |
2014-11-27 20:39:05 +08:00
Goal
----
In this tutorial you will learn how to:
- Use the function @ref cv::findHomography to find the transform between matched keypoints.
- Use the function @ref cv::perspectiveTransform to map the points.
\warning You need the <a href="https://github.com/opencv/opencv_contrib">OpenCV contrib modules</a> to be able to use the SURF features
(alternatives are ORB, KAZE, ... features).
2014-11-27 20:39:05 +08:00
Theory
------
Code
----
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
2021-12-22 21:01:26 +08:00
[here](https://github.com/opencv/opencv/tree/4.x/samples/cpp/tutorial_code/features2D/feature_homography/SURF_FLANN_matching_homography_Demo.cpp)
@include samples/cpp/tutorial_code/features2D/feature_homography/SURF_FLANN_matching_homography_Demo.cpp
@end_toggle
2014-11-27 20:39:05 +08:00
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
2021-12-22 21:01:26 +08:00
[here](https://github.com/opencv/opencv/tree/4.x/samples/java/tutorial_code/features2D/feature_homography/SURFFLANNMatchingHomographyDemo.java)
@include samples/java/tutorial_code/features2D/feature_homography/SURFFLANNMatchingHomographyDemo.java
@end_toggle
2014-11-27 20:39:05 +08:00
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
2021-12-22 21:01:26 +08:00
[here](https://github.com/opencv/opencv/tree/4.x/samples/python/tutorial_code/features2D/feature_homography/SURF_FLANN_matching_homography_Demo.py)
@include samples/python/tutorial_code/features2D/feature_homography/SURF_FLANN_matching_homography_Demo.py
@end_toggle
2014-11-27 20:39:05 +08:00
Explanation
-----------
Result
------
- And here is the result for the detected object (highlighted in green). Note that since the homography is estimated with a RANSAC approach,
detected false matches will not impact the homography calculation.
2014-11-27 20:39:05 +08:00
2014-11-28 21:21:28 +08:00
![](images/Feature_Homography_Result.jpg)