copied the latest tutorials & find_obj.py sample from trunk to 2.3 branch
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|
||||
.. _feature_description:
|
||||
|
||||
Feature Description
|
||||
*******************
|
||||
|
||||
Goal
|
||||
=====
|
||||
|
||||
In this tutorial you will learn how to:
|
||||
|
||||
.. container:: enumeratevisibleitemswithsquare
|
||||
|
||||
* Use the :descriptor_extractor:`DescriptorExtractor<>` interface in order to find the feature vector correspondent to the keypoints. Specifically:
|
||||
|
||||
* Use :surf_descriptor_extractor:`SurfDescriptorExtractor<>` and its function :descriptor_extractor:`compute<>` to perform the required calculations.
|
||||
* Use a :brute_force_matcher:`BruteForceMatcher<>` to match the features vector
|
||||
* Use the function :draw_matches:`drawMatches<>` to draw the detected matches.
|
||||
|
||||
|
||||
Theory
|
||||
======
|
||||
|
||||
Code
|
||||
====
|
||||
|
||||
This tutorial code's is shown lines below. You can also download it from `here <https://code.ros.org/svn/opencv/trunk/opencv/samples/cpp/tutorial_code/features2D/SURF_descriptor.cpp>`_
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
#include <stdio.h>
|
||||
#include <iostream>
|
||||
#include "opencv2/core/core.hpp"
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||||
#include "opencv2/features2d/features2d.hpp"
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||||
#include "opencv2/highgui/highgui.hpp"
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using namespace cv;
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|
||||
void readme();
|
||||
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||||
/** @function main */
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int main( int argc, char** argv )
|
||||
{
|
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if( argc != 3 )
|
||||
{ return -1; }
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||||
Mat img_1 = imread( argv[1], CV_LOAD_IMAGE_GRAYSCALE );
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||||
Mat img_2 = imread( argv[2], CV_LOAD_IMAGE_GRAYSCALE );
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if( !img_1.data || !img_2.data )
|
||||
{ return -1; }
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||||
//-- Step 1: Detect the keypoints using SURF Detector
|
||||
int minHessian = 400;
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||||
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||||
SurfFeatureDetector detector( minHessian );
|
||||
|
||||
std::vector<KeyPoint> keypoints_1, keypoints_2;
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detector.detect( img_1, keypoints_1 );
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||||
detector.detect( img_2, keypoints_2 );
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||||
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||||
//-- Step 2: Calculate descriptors (feature vectors)
|
||||
SurfDescriptorExtractor extractor;
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||||
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||||
Mat descriptors_1, descriptors_2;
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extractor.compute( img_1, keypoints_1, descriptors_1 );
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extractor.compute( img_2, keypoints_2, descriptors_2 );
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//-- Step 3: Matching descriptor vectors with a brute force matcher
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||||
BruteForceMatcher< L2<float> > matcher;
|
||||
std::vector< DMatch > matches;
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matcher.match( descriptors_1, descriptors_2, matches );
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//-- Draw matches
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Mat img_matches;
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drawMatches( img_1, keypoints_1, img_2, keypoints_2, matches, img_matches );
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//-- Show detected matches
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imshow("Matches", img_matches );
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|
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waitKey(0);
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||||
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return 0;
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||||
}
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|
||||
/** @function readme */
|
||||
void readme()
|
||||
{ std::cout << " Usage: ./SURF_descriptor <img1> <img2>" << std::endl; }
|
||||
|
||||
Explanation
|
||||
============
|
||||
|
||||
Result
|
||||
======
|
||||
|
||||
#. Here is the result after applying the BruteForce matcher between the two original images:
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||||
|
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.. image:: images/Feature_Description_BruteForce_Result.jpg
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:align: center
|
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:height: 200pt
|
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|
After Width: | Height: | Size: 117 KiB |
@@ -0,0 +1,97 @@
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.. _feature_detection:
|
||||
|
||||
Feature Detection
|
||||
******************
|
||||
|
||||
Goal
|
||||
=====
|
||||
|
||||
In this tutorial you will learn how to:
|
||||
|
||||
.. container:: enumeratevisibleitemswithsquare
|
||||
|
||||
* Use the :feature_detector:`FeatureDetector<>` interface in order to find interest points. Specifically:
|
||||
|
||||
* Use the :surf_feature_detector:`SurfFeatureDetector<>` and its function :feature_detector_detect:`detect<>` to perform the detection process
|
||||
* Use the function :draw_keypoints:`drawKeypoints<>` to draw the detected keypoints
|
||||
|
||||
|
||||
Theory
|
||||
======
|
||||
|
||||
Code
|
||||
====
|
||||
|
||||
This tutorial code's is shown lines below. You can also download it from `here <https://code.ros.org/svn/opencv/trunk/opencv/samples/cpp/tutorial_code/features2D/SURF_detector.cpp>`_
|
||||
|
||||
.. code-block:: cpp
|
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|
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#include <stdio.h>
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||||
#include <iostream>
|
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#include "opencv2/core/core.hpp"
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#include "opencv2/features2d/features2d.hpp"
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#include "opencv2/highgui/highgui.hpp"
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|
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using namespace cv;
|
||||
|
||||
void readme();
|
||||
|
||||
/** @function main */
|
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int main( int argc, char** argv )
|
||||
{
|
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if( argc != 3 )
|
||||
{ readme(); return -1; }
|
||||
|
||||
Mat img_1 = imread( argv[1], CV_LOAD_IMAGE_GRAYSCALE );
|
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Mat img_2 = imread( argv[2], CV_LOAD_IMAGE_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;
|
||||
|
||||
SurfFeatureDetector detector( minHessian );
|
||||
|
||||
std::vector<KeyPoint> keypoints_1, keypoints_2;
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detector.detect( img_1, keypoints_1 );
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detector.detect( img_2, keypoints_2 );
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//-- Draw keypoints
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||||
Mat img_keypoints_1; Mat img_keypoints_2;
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||||
|
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drawKeypoints( img_1, keypoints_1, img_keypoints_1, Scalar::all(-1), DrawMatchesFlags::DEFAULT );
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||||
drawKeypoints( img_2, keypoints_2, img_keypoints_2, Scalar::all(-1), DrawMatchesFlags::DEFAULT );
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||||
|
||||
//-- Show detected (drawn) keypoints
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||||
imshow("Keypoints 1", img_keypoints_1 );
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||||
imshow("Keypoints 2", img_keypoints_2 );
|
||||
|
||||
waitKey(0);
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||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/** @function readme */
|
||||
void readme()
|
||||
{ std::cout << " Usage: ./SURF_detector <img1> <img2>" << std::endl; }
|
||||
|
||||
Explanation
|
||||
============
|
||||
|
||||
Result
|
||||
======
|
||||
|
||||
#. Here is the result of the feature detection applied to the first image:
|
||||
|
||||
.. image:: images/Feature_Detection_Result_a.jpg
|
||||
:align: center
|
||||
:height: 125pt
|
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|
||||
#. And here is the result for the second image:
|
||||
|
||||
.. image:: images/Feature_Detection_Result_b.jpg
|
||||
:align: center
|
||||
:height: 200pt
|
||||
|
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|
After Width: | Height: | Size: 34 KiB |
|
After Width: | Height: | Size: 66 KiB |
@@ -0,0 +1,132 @@
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.. _feature_flann_matcher:
|
||||
|
||||
Feature Matching with FLANN
|
||||
****************************
|
||||
|
||||
Goal
|
||||
=====
|
||||
|
||||
In this tutorial you will learn how to:
|
||||
|
||||
.. container:: enumeratevisibleitemswithsquare
|
||||
|
||||
* Use the :flann_based_matcher:`FlannBasedMatcher<>` interface in order to perform a quick and efficient matching by using the :flann:`FLANN<>` ( *Fast Approximate Nearest Neighbor Search Library* )
|
||||
|
||||
|
||||
Theory
|
||||
======
|
||||
|
||||
Code
|
||||
====
|
||||
|
||||
This tutorial code's is shown lines below. You can also download it from `here <https://code.ros.org/svn/opencv/trunk/opencv/samples/cpp/tutorial_code/features2D/SURF_FlannMatcher.cpp>`_
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
#include <stdio.h>
|
||||
#include <iostream>
|
||||
#include "opencv2/core/core.hpp"
|
||||
#include "opencv2/features2d/features2d.hpp"
|
||||
#include "opencv2/highgui/highgui.hpp"
|
||||
|
||||
using namespace cv;
|
||||
|
||||
void readme();
|
||||
|
||||
/** @function main */
|
||||
int main( int argc, char** argv )
|
||||
{
|
||||
if( argc != 3 )
|
||||
{ readme(); return -1; }
|
||||
|
||||
Mat img_1 = imread( argv[1], CV_LOAD_IMAGE_GRAYSCALE );
|
||||
Mat img_2 = imread( argv[2], CV_LOAD_IMAGE_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;
|
||||
|
||||
SurfFeatureDetector detector( minHessian );
|
||||
|
||||
std::vector<KeyPoint> keypoints_1, keypoints_2;
|
||||
|
||||
detector.detect( img_1, keypoints_1 );
|
||||
detector.detect( img_2, keypoints_2 );
|
||||
|
||||
//-- Step 2: Calculate descriptors (feature vectors)
|
||||
SurfDescriptorExtractor extractor;
|
||||
|
||||
Mat descriptors_1, descriptors_2;
|
||||
|
||||
extractor.compute( img_1, keypoints_1, descriptors_1 );
|
||||
extractor.compute( img_2, keypoints_2, descriptors_2 );
|
||||
|
||||
//-- Step 3: 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 )
|
||||
//-- 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 < 2*min_dist )
|
||||
{ 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 < 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; }
|
||||
|
||||
Explanation
|
||||
============
|
||||
|
||||
Result
|
||||
======
|
||||
|
||||
#. Here is the result of the feature detection applied to the first image:
|
||||
|
||||
.. image:: images/Featur_FlannMatcher_Result.jpg
|
||||
:align: center
|
||||
:height: 250pt
|
||||
|
||||
#. Additionally, we get as console output the keypoints filtered:
|
||||
|
||||
.. image:: images/Feature_FlannMatcher_Keypoints_Result.jpg
|
||||
:align: center
|
||||
:height: 250pt
|
||||
|
||||
|
||||
|
||||
|
After Width: | Height: | Size: 79 KiB |
|
After Width: | Height: | Size: 77 KiB |
@@ -0,0 +1,148 @@
|
||||
.. _feature_homography:
|
||||
|
||||
Features2D + Homography to find a known object
|
||||
**********************************************
|
||||
|
||||
Goal
|
||||
=====
|
||||
|
||||
In this tutorial you will learn how to:
|
||||
|
||||
.. container:: enumeratevisibleitemswithsquare
|
||||
|
||||
* Use the function :find_homography:`findHomography<>` to find the transform between matched keypoints.
|
||||
* Use the function :perspective_transform:`perspectiveTransform<>` to map the points.
|
||||
|
||||
|
||||
Theory
|
||||
======
|
||||
|
||||
Code
|
||||
====
|
||||
|
||||
This tutorial code's is shown lines below. You can also download it from `here <https://code.ros.org/svn/opencv/trunk/opencv/samples/cpp/tutorial_code/features2D/SURF_Homography.cpp>`_
|
||||
|
||||
.. code-block:: cpp
|
||||
|
||||
#include <stdio.h>
|
||||
#include <iostream>
|
||||
#include "opencv2/core/core.hpp"
|
||||
#include "opencv2/features2d/features2d.hpp"
|
||||
#include "opencv2/highgui/highgui.hpp"
|
||||
#include "opencv2/calib3d/calib3d.hpp"
|
||||
|
||||
using namespace cv;
|
||||
|
||||
void readme();
|
||||
|
||||
/** @function main */
|
||||
int main( int argc, char** argv )
|
||||
{
|
||||
if( argc != 3 )
|
||||
{ readme(); return -1; }
|
||||
|
||||
Mat img_object = imread( argv[1], CV_LOAD_IMAGE_GRAYSCALE );
|
||||
Mat img_scene = imread( argv[2], CV_LOAD_IMAGE_GRAYSCALE );
|
||||
|
||||
if( !img_object.data || !img_scene.data )
|
||||
{ std::cout<< " --(!) Error reading images " << std::endl; return -1; }
|
||||
|
||||
//-- Step 1: Detect the keypoints using SURF Detector
|
||||
int minHessian = 400;
|
||||
|
||||
SurfFeatureDetector detector( minHessian );
|
||||
|
||||
std::vector<KeyPoint> keypoints_object, keypoints_scene;
|
||||
|
||||
detector.detect( img_object, keypoints_object );
|
||||
detector.detect( img_scene, keypoints_scene );
|
||||
|
||||
//-- Step 2: Calculate descriptors (feature vectors)
|
||||
SurfDescriptorExtractor extractor;
|
||||
|
||||
Mat descriptors_object, descriptors_scene;
|
||||
|
||||
extractor.compute( img_object, keypoints_object, descriptors_object );
|
||||
extractor.compute( img_scene, keypoints_scene, descriptors_scene );
|
||||
|
||||
//-- Step 3: 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),
|
||||
vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
|
||||
|
||||
//-- Localize the object
|
||||
std::vector<Point2f> obj;
|
||||
std::vector<Point2f> scene;
|
||||
|
||||
for( int 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, CV_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; }
|
||||
|
||||
Explanation
|
||||
============
|
||||
|
||||
Result
|
||||
======
|
||||
|
||||
|
||||
#. And here is the result for the detected object (highlighted in green)
|
||||
|
||||
.. image:: images/Feature_Homography_Result.jpg
|
||||
:align: center
|
||||
:height: 200pt
|
||||
|
||||
|
After Width: | Height: | Size: 90 KiB |
|
After Width: | Height: | Size: 117 KiB |
|
After Width: | Height: | Size: 34 KiB |
|
After Width: | Height: | Size: 79 KiB |
|
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@@ -72,7 +72,7 @@ Learn about how to use the feature points detectors, descriptors and matching f
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.. cssclass:: toctableopencv
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===================== ==============================================
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|Subpixel| **Title:** :ref:`corner_subpixeles`
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|Subpixel| **Title:** :ref:`corner_subpixeles`
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*Compatibility:* > OpenCV 2.0
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@@ -86,6 +86,84 @@ Learn about how to use the feature points detectors, descriptors and matching f
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:height: 90pt
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:width: 90pt
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+
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.. tabularcolumns:: m{100pt} m{300pt}
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.. cssclass:: toctableopencv
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===================== ==============================================
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|FeatureDetect| **Title:** :ref:`feature_detection`
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*Compatibility:* > OpenCV 2.0
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*Author:* |Author_AnaH|
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In this tutorial, you will use *features2d* to detect interest points.
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===================== ==============================================
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.. |FeatureDetect| image:: images/Feature_Detection_Tutorial_Cover.jpg
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:height: 90pt
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:width: 90pt
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+
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.. tabularcolumns:: m{100pt} m{300pt}
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.. cssclass:: toctableopencv
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===================== ==============================================
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|FeatureDescript| **Title:** :ref:`feature_description`
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*Compatibility:* > OpenCV 2.0
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*Author:* |Author_AnaH|
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In this tutorial, you will use *features2d* to calculate feature vectors.
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===================== ==============================================
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.. |FeatureDescript| image:: images/Feature_Description_Tutorial_Cover.jpg
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:height: 90pt
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:width: 90pt
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+
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.. tabularcolumns:: m{100pt} m{300pt}
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.. cssclass:: toctableopencv
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===================== ==============================================
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|FeatureFlann| **Title:** :ref:`feature_flann_matcher`
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*Compatibility:* > OpenCV 2.0
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*Author:* |Author_AnaH|
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In this tutorial, you will use the FLANN library to make a fast matching.
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===================== ==============================================
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.. |FeatureFlann| image:: images/Feature_Flann_Matcher_Tutorial_Cover.jpg
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:height: 90pt
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:width: 90pt
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+
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.. tabularcolumns:: m{100pt} m{300pt}
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.. cssclass:: toctableopencv
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===================== ==============================================
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|FeatureHomo| **Title:** :ref:`feature_homography`
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*Compatibility:* > OpenCV 2.0
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*Author:* |Author_AnaH|
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In this tutorial, you will use *features2d* and *calib3d* to detect an object in a scene.
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===================== ==============================================
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.. |FeatureHomo| image:: images/Feature_Homography_Tutorial_Cover.jpg
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:height: 90pt
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:width: 90pt
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+
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.. tabularcolumns:: m{100pt} m{300pt}
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.. cssclass:: toctableopencv
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@@ -112,8 +190,17 @@ Learn about how to use the feature points detectors, descriptors and matching f
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.. toctree::
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:hidden:
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../feature_description/feature_description
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../feature_detection/feature_detection
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../trackingmotion/harris_detector/harris_detector
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../feature_flann_matcher/feature_flann_matcher
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../feature_homography/feature_homography
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../trackingmotion/good_features_to_track/good_features_to_track.rst
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../trackingmotion/generic_corner_detector/generic_corner_detector
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../trackingmotion/corner_subpixeles/corner_subpixeles
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../detection_of_planar_objects/detection_of_planar_objects
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../feature_detection/feature_detection
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../feature_detection/feature_description
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../feature_flann_matcher/feature_flann_matcher
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../feature_homography/feature_homography
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../detection_of_planar_objects/detection_of_planar_objects
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@@ -88,14 +88,14 @@ This tutorial code's is shown lines below. You can also download it from `here <
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/// Apply corner detection
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goodFeaturesToTrack( src_gray,
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corners,
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maxCorners,
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qualityLevel,
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minDistance,
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Mat(),
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blockSize,
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useHarrisDetector,
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k );
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corners,
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maxCorners,
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qualityLevel,
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minDistance,
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Mat(),
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blockSize,
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useHarrisDetector,
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k );
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/// Draw corners detected
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@@ -116,7 +116,7 @@ Explanation
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Result
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||||
======
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||||
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.. image:: images/Shi_Tomasi_Detector_Result.jpg
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.. image:: images/Feature_Detection_Result_a.jpg
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:align: center
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|
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|
After Width: | Height: | Size: 34 KiB |
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@@ -6,15 +6,46 @@ Harris corner detector
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Goal
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||||
=====
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||||
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In this tutorial you will learn how to:
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In this tutorial you will learn:
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.. container:: enumeratevisibleitemswithsquare
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* What features are and why they are important
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* Use the function :corner_harris:`cornerHarris <>` to detect corners using the Harris-Stephens method.
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Theory
|
||||
======
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||||
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What is a feature?
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||||
-------------------
|
||||
|
||||
.. container:: enumeratevisibleitemswithsquare
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||||
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||||
* In computer vision, usually we need to find matching points between different frames of an environment. Why? If we know how two images relate to each other, we can use *both* images to extract information of them.
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* When we say **matching points** we are referring, in a general sense, to *characteristics* in the scene that we can recognize easily. We call these characteristics **features**.
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* **So, what characteristics should a feature have?**
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||||
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* It must be *uniquely recognizable*
|
||||
|
||||
|
||||
Types of Image Features
|
||||
------------------------
|
||||
|
||||
To mention a few:
|
||||
|
||||
.. container:: enumeratevisibleitemswithsquare
|
||||
|
||||
* Edges
|
||||
* Corner (also known as interest points)
|
||||
* Blobs (also known as regions of interest )
|
||||
|
||||
In this tutorial we will study the *corner* features, specifically.
|
||||
|
||||
Why is a corner so special?
|
||||
----------------------------
|
||||
|
||||
Code
|
||||
====
|
||||
|
||||
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||||