Merge remote-tracking branch 'upstream/3.4' into merge-3.4

Revert "documentation: avoid links to 'master' branch from 3.4 maintenance branch"
This reverts commit 9ba9358ecb.

Revert "documentation: avoid links to 'master' branch from 3.4 maintenance branch (2)"
This reverts commit f185802489.
This commit is contained in:
Alexander Alekhin
2018-06-04 19:24:09 +03:00
147 changed files with 5707 additions and 2831 deletions
@@ -10,74 +10,35 @@ In this tutorial you will learn how to:
to the keypoints. Specifically:
- Use cv::xfeatures2d::SURF and its function cv::xfeatures2d::SURF::compute to perform the
required calculations.
- Use a @ref cv::BFMatcher to match the features vector
- Use a @ref cv::DescriptorMatcher to match the features vector
- Use the function @ref cv::drawMatches to draw the detected matches.
\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).
Theory
------
Code
----
This tutorial code's is shown lines below.
@code{.cpp}
#include <stdio.h>
#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/features2d.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/xfeatures2d.hpp"
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/features2D/feature_description/SURF_matching_Demo.cpp)
@include samples/cpp/tutorial_code/features2D/feature_description/SURF_matching_Demo.cpp
@end_toggle
using namespace cv;
using namespace cv::xfeatures2d;
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/features2D/feature_description/SURFMatchingDemo.java)
@include samples/java/tutorial_code/features2D/feature_description/SURFMatchingDemo.java
@end_toggle
void readme();
/* @function main */
int main( int argc, char** argv )
{
if( argc != 3 )
{ return -1; }
Mat img_1 = imread( argv[1], IMREAD_GRAYSCALE );
Mat img_2 = imread( argv[2], IMREAD_GRAYSCALE );
if( !img_1.data || !img_2.data )
{ return -1; }
//-- Step 1: Detect the keypoints using SURF Detector, compute the descriptors
int minHessian = 400;
Ptr<SURF> detector = SURF::create();
detector->setHessianThreshold(minHessian);
std::vector<KeyPoint> keypoints_1, keypoints_2;
Mat descriptors_1, descriptors_2;
detector->detectAndCompute( img_1, Mat(), keypoints_1, descriptors_1 );
detector->detectAndCompute( img_2, Mat(), keypoints_2, descriptors_2 );
//-- Step 2: Matching descriptor vectors with a brute force matcher
BFMatcher matcher(NORM_L2);
std::vector< DMatch > matches;
matcher.match( descriptors_1, descriptors_2, matches );
//-- Draw matches
Mat img_matches;
drawMatches( img_1, keypoints_1, img_2, keypoints_2, matches, img_matches );
//-- Show detected matches
imshow("Matches", img_matches );
waitKey(0);
return 0;
}
/* @function readme */
void readme()
{ std::cout << " Usage: ./SURF_descriptor <img1> <img2>" << std::endl; }
@endcode
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/features2D/feature_description/SURF_matching_Demo.py)
@include samples/python/tutorial_code/features2D/feature_description/SURF_matching_Demo.py
@end_toggle
Explanation
-----------
@@ -11,67 +11,32 @@ In this tutorial you will learn how to:
detection process
- Use the function @ref cv::drawKeypoints to draw the detected keypoints
\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).
Theory
------
Code
----
This tutorial code's is shown lines below.
@code{.cpp}
#include <stdio.h>
#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/features2d.hpp"
#include "opencv2/xfeatures2d.hpp"
#include "opencv2/highgui.hpp"
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/features2D/feature_detection/SURF_detection_Demo.cpp)
@include samples/cpp/tutorial_code/features2D/feature_detection/SURF_detection_Demo.cpp
@end_toggle
using namespace cv;
using namespace cv::xfeatures2d;
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/features2D/feature_detection/SURFDetectionDemo.java)
@include samples/java/tutorial_code/features2D/feature_detection/SURFDetectionDemo.java
@end_toggle
void readme();
/* @function main */
int main( int argc, char** argv )
{
if( argc != 3 )
{ readme(); return -1; }
Mat img_1 = imread( argv[1], IMREAD_GRAYSCALE );
Mat img_2 = imread( argv[2], IMREAD_GRAYSCALE );
if( !img_1.data || !img_2.data )
{ std::cout<< " --(!) Error reading images " << std::endl; return -1; }
//-- Step 1: Detect the keypoints using SURF Detector
int minHessian = 400;
Ptr<SURF> detector = SURF::create( minHessian );
std::vector<KeyPoint> keypoints_1, keypoints_2;
detector->detect( img_1, keypoints_1 );
detector->detect( img_2, keypoints_2 );
//-- Draw keypoints
Mat img_keypoints_1; Mat img_keypoints_2;
drawKeypoints( img_1, keypoints_1, img_keypoints_1, Scalar::all(-1), DrawMatchesFlags::DEFAULT );
drawKeypoints( img_2, keypoints_2, img_keypoints_2, Scalar::all(-1), DrawMatchesFlags::DEFAULT );
//-- Show detected (drawn) keypoints
imshow("Keypoints 1", img_keypoints_1 );
imshow("Keypoints 2", img_keypoints_2 );
waitKey(0);
return 0;
}
/* @function readme */
void readme()
{ std::cout << " Usage: ./SURF_detector <img1> <img2>" << std::endl; }
@endcode
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/features2D/feature_detection/SURF_detection_Demo.py)
@include samples/python/tutorial_code/features2D/feature_detection/SURF_detection_Demo.py
@end_toggle
Explanation
-----------
@@ -79,10 +44,10 @@ Explanation
Result
------
-# Here is the result of the feature detection applied to the first image:
-# Here is the result of the feature detection applied to the `box.png` image:
![](images/Feature_Detection_Result_a.jpg)
-# And here is the result for the second image:
-# And here is the result for the `box_in_scene.png` image:
![](images/Feature_Detection_Result_b.jpg)
@@ -9,114 +9,57 @@ In this tutorial you will learn how to:
- Use the @ref cv::FlannBasedMatcher interface in order to perform a quick and efficient matching
by using the @ref flann module
\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).
Theory
------
Classical feature descriptors (SIFT, SURF, ...) are usually compared and matched using the Euclidean distance (or L2-norm).
Since SIFT and SURF descriptors represent the histogram of oriented gradient (of the Haar wavelet response for SURF)
in a neighborhood, alternatives of the Euclidean distance are histogram-based metrics (\f$ \chi^{2} \f$, Earth Movers Distance (EMD), ...).
Arandjelovic et al. proposed in @cite Arandjelovic:2012:TTE:2354409.2355123 to extend to the RootSIFT descriptor:
> a square root (Hellinger) kernel instead of the standard Euclidean distance to measure the similarity between SIFT descriptors
> leads to a dramatic performance boost in all stages of the pipeline.
Binary descriptors (ORB, BRISK, ...) are matched using the <a href="https://en.wikipedia.org/wiki/Hamming_distance">Hamming distance</a>.
This distance is equivalent to count the number of different elements for binary strings (population count after applying a XOR operation):
\f[ d_{hamming} \left ( a,b \right ) = \sum_{i=0}^{n-1} \left ( a_i \oplus b_i \right ) \f]
To filter the matches, Lowe proposed in @cite Lowe:2004:DIF:993451.996342 to use a distance ratio test to try to eliminate false matches.
The distance ratio between the two nearest matches of a considered keypoint is computed and it is a good match when this value is below
a thresold. Indeed, this ratio allows helping to discriminate between ambiguous matches (distance ratio between the two nearest neighbors is
close to one) and well discriminated matches. The figure below from the SIFT paper illustrates the probability that a match is correct
based on the nearest-neighbor distance ratio test.
![](images/Feature_FlannMatcher_Lowe_ratio_test.png)
Alternative or additional filterering tests are:
- cross check test (good match \f$ \left( f_a, f_b \right) \f$ if feature \f$ f_b \f$ is the best match for \f$ f_a \f$ in \f$ I_b \f$
and feature \f$ f_a \f$ is the best match for \f$ f_b \f$ in \f$ I_a \f$)
- geometric test (eliminate matches that do not fit to a geometric model, e.g. RANSAC or robust homography for planar objects)
Code
----
This tutorial code's is shown lines below.
@code{.cpp}
/*
* @file SURF_FlannMatcher
* @brief SURF detector + descriptor + FLANN Matcher
* @author A. Huaman
*/
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/features2D/feature_flann_matcher/SURF_FLANN_matching_Demo.cpp)
@include samples/cpp/tutorial_code/features2D/feature_flann_matcher/SURF_FLANN_matching_Demo.cpp
@end_toggle
#include <stdio.h>
#include <iostream>
#include <stdio.h>
#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/features2d.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/xfeatures2d.hpp"
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/features2D/feature_flann_matcher/SURFFLANNMatchingDemo.java)
@include samples/java/tutorial_code/features2D/feature_flann_matcher/SURFFLANNMatchingDemo.java
@end_toggle
using namespace std;
using namespace cv;
using namespace cv::xfeatures2d;
void readme();
/*
* @function main
* @brief Main function
*/
int main( int argc, char** argv )
{
if( argc != 3 )
{ readme(); return -1; }
Mat img_1 = imread( argv[1], IMREAD_GRAYSCALE );
Mat img_2 = imread( argv[2], IMREAD_GRAYSCALE );
if( !img_1.data || !img_2.data )
{ std::cout<< " --(!) Error reading images " << std::endl; return -1; }
//-- Step 1: Detect the keypoints using SURF Detector, compute the descriptors
int minHessian = 400;
Ptr<SURF> detector = SURF::create();
detector->setHessianThreshold(minHessian);
std::vector<KeyPoint> keypoints_1, keypoints_2;
Mat descriptors_1, descriptors_2;
detector->detectAndCompute( img_1, Mat(), keypoints_1, descriptors_1 );
detector->detectAndCompute( img_2, Mat(), keypoints_2, descriptors_2 );
//-- Step 2: Matching descriptor vectors using FLANN matcher
FlannBasedMatcher matcher;
std::vector< DMatch > matches;
matcher.match( descriptors_1, descriptors_2, matches );
double max_dist = 0; double min_dist = 100;
//-- Quick calculation of max and min distances between keypoints
for( int i = 0; i < descriptors_1.rows; i++ )
{ double dist = matches[i].distance;
if( dist < min_dist ) min_dist = dist;
if( dist > max_dist ) max_dist = dist;
}
printf("-- Max dist : %f \n", max_dist );
printf("-- Min dist : %f \n", min_dist );
//-- Draw only "good" matches (i.e. whose distance is less than 2*min_dist,
//-- or a small arbitrary value ( 0.02 ) in the event that min_dist is very
//-- small)
//-- PS.- radiusMatch can also be used here.
std::vector< DMatch > good_matches;
for( int i = 0; i < descriptors_1.rows; i++ )
{ if( matches[i].distance <= max(2*min_dist, 0.02) )
{ good_matches.push_back( matches[i]); }
}
//-- Draw only "good" matches
Mat img_matches;
drawMatches( img_1, keypoints_1, img_2, keypoints_2,
good_matches, img_matches, Scalar::all(-1), Scalar::all(-1),
vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
//-- Show detected matches
imshow( "Good Matches", img_matches );
for( int i = 0; i < (int)good_matches.size(); i++ )
{ printf( "-- Good Match [%d] Keypoint 1: %d -- Keypoint 2: %d \n", i, good_matches[i].queryIdx, good_matches[i].trainIdx ); }
waitKey(0);
return 0;
}
/*
* @function readme
*/
void readme()
{ std::cout << " Usage: ./SURF_FlannMatcher <img1> <img2>" << std::endl; }
@endcode
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/features2D/feature_flann_matcher/SURF_FLANN_matching_Demo.py)
@include samples/python/tutorial_code/features2D/feature_flann_matcher/SURF_FLANN_matching_Demo.py
@end_toggle
Explanation
-----------
@@ -124,10 +67,6 @@ Explanation
Result
------
-# Here is the result of the feature detection applied to the first image:
- Here is the result of the SURF feature matching using the distance ratio test:
![](images/Featur_FlannMatcher_Result.jpg)
-# Additionally, we get as console output the keypoints filtered:
![](images/Feature_FlannMatcher_Keypoints_Result.jpg)
![](images/Feature_FlannMatcher_Result_ratio_test.jpg)
Binary file not shown.

After

Width:  |  Height:  |  Size: 53 KiB

Binary file not shown.

After

Width:  |  Height:  |  Size: 79 KiB

@@ -9,125 +9,40 @@ 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).
Theory
------
Code
----
This tutorial code's is shown lines below.
@code{.cpp}
#include <stdio.h>
#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/features2d.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/calib3d.hpp"
#include "opencv2/xfeatures2d.hpp"
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/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
using namespace cv;
using namespace cv::xfeatures2d;
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/features2D/feature_homography/SURFFLANNMatchingHomographyDemo.java)
@include samples/java/tutorial_code/features2D/feature_homography/SURFFLANNMatchingHomographyDemo.java
@end_toggle
void readme();
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/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
/* @function main */
int main( int argc, char** argv )
{
if( argc != 3 )
{ readme(); return -1; }
Mat img_object = imread( argv[1], IMREAD_GRAYSCALE );
Mat img_scene = imread( argv[2], IMREAD_GRAYSCALE );
if( !img_object.data || !img_scene.data )
{ std::cout<< " --(!) Error reading images " << std::endl; return -1; }
//-- Step 1: Detect the keypoints and extract descriptors using SURF
int minHessian = 400;
Ptr<SURF> detector = SURF::create( minHessian );
std::vector<KeyPoint> keypoints_object, keypoints_scene;
Mat descriptors_object, descriptors_scene;
detector->detectAndCompute( img_object, Mat(), keypoints_object, descriptors_object );
detector->detectAndCompute( img_scene, Mat(), keypoints_scene, descriptors_scene );
//-- Step 2: Matching descriptor vectors using FLANN matcher
FlannBasedMatcher matcher;
std::vector< DMatch > matches;
matcher.match( descriptors_object, descriptors_scene, matches );
double max_dist = 0; double min_dist = 100;
//-- Quick calculation of max and min distances between keypoints
for( int i = 0; i < descriptors_object.rows; i++ )
{ double dist = matches[i].distance;
if( dist < min_dist ) min_dist = dist;
if( dist > max_dist ) max_dist = dist;
}
printf("-- Max dist : %f \n", max_dist );
printf("-- Min dist : %f \n", min_dist );
//-- Draw only "good" matches (i.e. whose distance is less than 3*min_dist )
std::vector< DMatch > good_matches;
for( int i = 0; i < descriptors_object.rows; i++ )
{ if( matches[i].distance <= 3*min_dist )
{ good_matches.push_back( matches[i]); }
}
Mat img_matches;
drawMatches( img_object, keypoints_object, img_scene, keypoints_scene,
good_matches, img_matches, Scalar::all(-1), Scalar::all(-1),
std::vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
//-- Localize the object
std::vector<Point2f> obj;
std::vector<Point2f> scene;
for( size_t i = 0; i < good_matches.size(); i++ )
{
//-- Get the keypoints from the good matches
obj.push_back( keypoints_object[ good_matches[i].queryIdx ].pt );
scene.push_back( keypoints_scene[ good_matches[i].trainIdx ].pt );
}
Mat H = findHomography( obj, scene, RANSAC );
//-- Get the corners from the image_1 ( the object to be "detected" )
std::vector<Point2f> obj_corners(4);
obj_corners[0] = cvPoint(0,0); obj_corners[1] = cvPoint( img_object.cols, 0 );
obj_corners[2] = cvPoint( img_object.cols, img_object.rows ); obj_corners[3] = cvPoint( 0, img_object.rows );
std::vector<Point2f> scene_corners(4);
perspectiveTransform( obj_corners, scene_corners, H);
//-- Draw lines between the corners (the mapped object in the scene - image_2 )
line( img_matches, scene_corners[0] + Point2f( img_object.cols, 0), scene_corners[1] + Point2f( img_object.cols, 0), Scalar(0, 255, 0), 4 );
line( img_matches, scene_corners[1] + Point2f( img_object.cols, 0), scene_corners[2] + Point2f( img_object.cols, 0), Scalar( 0, 255, 0), 4 );
line( img_matches, scene_corners[2] + Point2f( img_object.cols, 0), scene_corners[3] + Point2f( img_object.cols, 0), Scalar( 0, 255, 0), 4 );
line( img_matches, scene_corners[3] + Point2f( img_object.cols, 0), scene_corners[0] + Point2f( img_object.cols, 0), Scalar( 0, 255, 0), 4 );
//-- Show detected matches
imshow( "Good Matches & Object detection", img_matches );
waitKey(0);
return 0;
}
/* @function readme */
void readme()
{ std::cout << " Usage: ./SURF_descriptor <img1> <img2>" << std::endl; }
@endcode
Explanation
-----------
Result
------
-# And here is the result for the detected object (highlighted in green)
- 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.
![](images/Feature_Homography_Result.jpg)
Binary file not shown.

Before

Width:  |  Height:  |  Size: 90 KiB

After

Width:  |  Height:  |  Size: 88 KiB

@@ -6,39 +6,51 @@ OpenCV.
- @subpage tutorial_harris_detector
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
Why is it a good idea to track corners? We learn to use the Harris method to detect
corners
Why is it a good idea to track corners? We learn how to use the Harris method to detect
corners.
- @subpage tutorial_good_features_to_track
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
Where we use an improved method to detect corners more accuratelyI
Where we use an improved method to detect corners more accurately.
- @subpage tutorial_generic_corner_detector
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
Here you will learn how to use OpenCV functions to make your personalized corner detector!
- @subpage tutorial_corner_subpixeles
*Languages:* C++, Java, Python
- @subpage tutorial_corner_subpixels
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
Is pixel resolution enough? Here we learn a simple method to improve our accuracy.
Is pixel resolution enough? Here we learn a simple method to improve our corner location accuracy.
- @subpage tutorial_feature_detection
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
@@ -47,6 +59,8 @@ OpenCV.
- @subpage tutorial_feature_description
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
@@ -55,6 +69,8 @@ OpenCV.
- @subpage tutorial_feature_flann_matcher
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
@@ -63,6 +79,8 @@ OpenCV.
- @subpage tutorial_feature_homography
*Languages:* C++, Java, Python
*Compatibility:* \> OpenCV 2.0
*Author:* Ana Huamán
@@ -1,32 +0,0 @@
Detecting corners location in subpixeles {#tutorial_corner_subpixeles}
========================================
Goal
----
In this tutorial you will learn how to:
- Use the OpenCV function @ref cv::cornerSubPix to find more exact corner positions (more exact
than integer pixels).
Theory
------
Code
----
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp)
@include samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp
Explanation
-----------
Result
------
![](images/Corner_Subpixeles_Original_Image.jpg)
Here is the result:
![](images/Corner_Subpixeles_Result.jpg)
@@ -0,0 +1,46 @@
Detecting corners location in subpixels {#tutorial_corner_subpixels}
=======================================
Goal
----
In this tutorial you will learn how to:
- Use the OpenCV function @ref cv::cornerSubPix to find more exact corner positions (more exact
than integer pixels).
Theory
------
Code
----
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp)
@include samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp
@end_toggle
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/corner_subpixels/CornerSubPixDemo.java)
@include samples/java/tutorial_code/TrackingMotion/corner_subpixels/CornerSubPixDemo.java
@end_toggle
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/corner_subpixels/cornerSubPix_Demo.py)
@include samples/python/tutorial_code/TrackingMotion/corner_subpixels/cornerSubPix_Demo.py
@end_toggle
Explanation
-----------
Result
------
![](images/Corner_Subpixels_Original_Image.jpg)
Here is the result:
![](images/Corner_Subpixels_Result.jpg)
@@ -1,5 +1,5 @@
Creating yor own corner detector {#tutorial_generic_corner_detector}
================================
Creating your own corner detector {#tutorial_generic_corner_detector}
=================================
Goal
----
@@ -10,7 +10,7 @@ In this tutorial you will learn how to:
to determine if a pixel is a corner.
- Use the OpenCV function @ref cv::cornerMinEigenVal to find the minimum eigenvalues for corner
detection.
- To implement our own version of the Harris detector as well as the Shi-Tomasi detector, by using
- Implement our own version of the Harris detector as well as the Shi-Tomasi detector, by using
the two functions above.
Theory
@@ -19,10 +19,26 @@ Theory
Code
----
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp)
@include cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp
@include samples/cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp
@end_toggle
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/generic_corner_detector/CornerDetectorDemo.java)
@include samples/java/tutorial_code/TrackingMotion/generic_corner_detector/CornerDetectorDemo.java
@end_toggle
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/generic_corner_detector/cornerDetector_Demo.py)
@include samples/python/tutorial_code/TrackingMotion/generic_corner_detector/cornerDetector_Demo.py
@end_toggle
Explanation
-----------
@@ -6,7 +6,7 @@ Goal
In this tutorial you will learn how to:
- Use the function @ref cv::goodFeaturesToTrack to detect corners using the Shi-Tomasi method.
- Use the function @ref cv::goodFeaturesToTrack to detect corners using the Shi-Tomasi method (@cite Shi94).
Theory
------
@@ -14,9 +14,23 @@ Theory
Code
----
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/goodFeaturesToTrack_Demo.cpp)
@include samples/cpp/tutorial_code/TrackingMotion/goodFeaturesToTrack_Demo.cpp
@end_toggle
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/good_features_to_track/GoodFeaturesToTrackDemo.java)
@include samples/java/tutorial_code/TrackingMotion/good_features_to_track/GoodFeaturesToTrackDemo.java
@end_toggle
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/good_features_to_track/goodFeaturesToTrack_Demo.py)
@include samples/python/tutorial_code/TrackingMotion/good_features_to_track/goodFeaturesToTrack_Demo.py
@end_toggle
Explanation
-----------
@@ -24,4 +38,4 @@ Explanation
Result
------
![](images/Feature_Detection_Result_a.jpg)
![](images/good_features_to_track_Shi_Tomasi.jpg)
Binary file not shown.

Before

Width:  |  Height:  |  Size: 34 KiB

Binary file not shown.

Before

Width:  |  Height:  |  Size: 66 KiB

Binary file not shown.

After

Width:  |  Height:  |  Size: 27 KiB

@@ -118,9 +118,23 @@ In this tutorial we will study the *corner* features, specifically.
Code
----
@add_toggle_cpp
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerHarris_Demo.cpp)
@include samples/cpp/tutorial_code/TrackingMotion/cornerHarris_Demo.cpp
@end_toggle
@add_toggle_java
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/harris_detector/CornerHarrisDemo.java)
@include samples/java/tutorial_code/TrackingMotion/harris_detector/CornerHarrisDemo.java
@end_toggle
@add_toggle_python
This tutorial code's is shown lines below. You can also download it from
[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/harris_detector/cornerHarris_Demo.py)
@include samples/python/tutorial_code/TrackingMotion/harris_detector/cornerHarris_Demo.py
@end_toggle
Explanation
-----------