In the following snippet of code, it is shown how to detect lines from an image. The LSD extractor is initialized with LSD_REFINE_ADV option; remaining parameters are left to their default values. A mask of ones is used in order to accept all extracted lines, which, at the end, are displayed using random colors for octave 0.
55 static const char* keys =
56 {
"{@image_path | | Image path }" };
60 cout <<
"\nThis example shows the functionalities of lines extraction " <<
"furnished by BinaryDescriptor class\n" 61 <<
"Please, run this sample using a command in the form\n" <<
"./example_line_descriptor_lines_extraction <path_to_input_image>" << endl;
64 int main(
int argc,
char** argv )
70 if( image_path.
empty() )
78 if( imageMat.
data == NULL )
80 std::cout <<
"Error, image could not be loaded. Please, check its path" << std::endl;
91 vector<KeyLine> lines;
95 bd->detect( imageMat, lines, 2, 1, mask );
100 for (
size_t i = 0; i < lines.size(); i++ )
106 int R = ( rand() % (int) ( 255 + 1 ) );
107 int G = ( rand() % (int) ( 255 + 1 ) );
108 int B = ( rand() % (int) ( 255 + 1 ) );
115 line( output, pt1, pt2,
Scalar( B, G, R ), 3 );
121 imshow(
"LSD lines", output );
float startPointX
Definition: descriptor.hpp:129
Scalar_< double > Scalar
Definition: types.hpp:602
void cvtColor(InputArray src, OutputArray dst, int code, int dstCn=0)
Converts an image from one color space to another.
static Ptr< LSDDetector > createLSDDetector()
Creates ad LSDDetector object, using smart pointers.
int channels() const
Returns the number of matrix channels.
Mat imread(const String &filename, int flags=IMREAD_COLOR)
Loads an image from a file.
static MatExpr ones(int rows, int cols, int type)
Returns an array of all 1's of the specified size and type.
uchar * data
pointer to the data
Definition: mat.hpp:1909
void imshow(const String &winname, InputArray mat)
Displays an image in the specified window.
float startPointY
Definition: descriptor.hpp:130
Definition: affine.hpp:51
Designed for command line parsing.
Definition: utility.hpp:734
Definition: imgproc.hpp:540
Template class for 2D points specified by its coordinates x and y.
Definition: types.hpp:148
int octave
Definition: descriptor.hpp:115
float endPointX
Definition: descriptor.hpp:131
void line(InputOutputArray img, Point pt1, Point pt2, const Scalar &color, int thickness=1, int lineType=LINE_8, int shift=0)
Draws a line segment connecting two points.
Mat clone() const
Creates a full copy of the array and the underlying data.
Point_< float > Point2f
Definition: types.hpp:180
MatSize size
Definition: mat.hpp:1926
Definition: descriptor.hpp:77
Template class for smart pointers with shared ownership.
Definition: cvstd.hpp:280
for i
Definition: modelConvert.m:63
A class to represent a line.
Definition: descriptor.hpp:105
#define CV_8UC1
Definition: interface.h:82
Definition: cvstd.hpp:477
n-dimensional dense array class
Definition: mat.hpp:740
float endPointY
Definition: descriptor.hpp:132
int waitKey(int delay=0)
Waits for a pressed key.
Once keylines have been detected, it is possible to compute their descriptors as shown in the following:
55 static const char* keys =
56 {
"{@image_path | | Image path }" };
60 std::cout <<
"\nThis example shows the functionalities of lines extraction " <<
"and descriptors computation furnished by BinaryDescriptor class\n" 61 <<
"Please, run this sample using a command in the form\n" <<
"./example_line_descriptor_compute_descriptors <path_to_input_image>" 65 int main(
int argc,
char** argv )
71 if( image_path.
empty() )
79 if( imageMat.
data == NULL )
81 std::cout <<
"Error, image could not be loaded. Please, check its path" << std::endl;
91 std::vector<KeyLine> keylines;
92 bd->detect( imageMat, keylines, mask );
97 bd->compute( imageMat, keylines, descriptors);
static Ptr< BinaryDescriptor > createBinaryDescriptor()
Create a BinaryDescriptor object with default parameters (or with the ones provided) and return a sma...
Mat imread(const String &filename, int flags=IMREAD_COLOR)
Loads an image from a file.
static MatExpr ones(int rows, int cols, int type)
Returns an array of all 1's of the specified size and type.
uchar * data
pointer to the data
Definition: mat.hpp:1909
Definition: affine.hpp:51
Designed for command line parsing.
Definition: utility.hpp:734
MatSize size
Definition: mat.hpp:1926
Definition: descriptor.hpp:77
Template class for smart pointers with shared ownership.
Definition: cvstd.hpp:280
#define CV_8UC1
Definition: interface.h:82
Definition: cvstd.hpp:477
n-dimensional dense array class
Definition: mat.hpp:740
If we have extracted descriptors from two different images, it is possible to search for matches among them. One way of doing it is matching exactly a descriptor to each input query descriptor, choosing the one at closest distance:
51 #define MATCHES_DIST_THRESHOLD 25 56 static const char* keys =
57 {
"{@image_path1 | | Image path 1 }" 58 "{@image_path2 | | Image path 2 }" };
62 std::cout <<
"\nThis example shows the functionalities of lines extraction " <<
"and descriptors computation furnished by BinaryDescriptor class\n" 63 <<
"Please, run this sample using a command in the form\n" <<
"./example_line_descriptor_compute_descriptors <path_to_input_image 1>" 64 <<
"<path_to_input_image 2>" << std::endl;
68 int main(
int argc,
char** argv )
75 if( image_path1.
empty() || image_path2.empty() )
85 if( imageMat1.
data == NULL || imageMat2.
data == NULL )
87 std::cout <<
"Error, images could not be loaded. Please, check their path" << std::endl;
98 std::vector<KeyLine> keylines1, keylines2;
101 ( *bd )( imageMat1, mask1, keylines1, descr1,
false, false );
102 ( *bd )( imageMat2, mask2, keylines2, descr2,
false, false );
105 std::vector<KeyLine> lbd_octave1, lbd_octave2;
106 Mat left_lbd, right_lbd;
107 for (
int i = 0; i < (int) keylines1.size(); i++ )
109 if( keylines1[i].octave == 0 )
116 for (
int j = 0; j < (int) keylines2.size(); j++ )
118 if( keylines2[j].octave == 0 )
120 lbd_octave2.push_back( keylines2[j] );
129 std::vector<DMatch> matches;
130 bdm->
match( left_lbd, right_lbd, matches );
133 std::vector<DMatch> good_matches;
134 for (
int i = 0; i < (int) matches.size(); i++ )
136 if( matches[i].distance < MATCHES_DIST_THRESHOLD )
137 good_matches.push_back( matches[i] );
143 std::vector<char> mask( matches.size(), 1 );
147 imshow(
"Matches", outImg );
149 imwrite(
"/home/ubisum/Desktop/images/env_match/matches.jpg", outImg);
154 std::vector<KeyLine> klsd1, klsd2;
155 Mat lsd_descr1, lsd_descr2;
156 lsd->
detect( imageMat1, klsd1, 2, 2, mask1 );
157 lsd->
detect( imageMat2, klsd2, 2, 2, mask2 );
160 bd->compute( imageMat1, klsd1, lsd_descr1 );
161 bd->compute( imageMat2, klsd2, lsd_descr2 );
164 std::vector<KeyLine> octave0_1, octave0_2;
165 Mat leftDEscr, rightDescr;
166 for (
int i = 0; i < (int) klsd1.size(); i++ )
168 if( klsd1[i].octave == 1 )
170 octave0_1.push_back( klsd1[i] );
175 for (
int j = 0; j < (int) klsd2.size(); j++ )
177 if( klsd2[j].octave == 1 )
179 octave0_2.push_back( klsd2[j] );
185 std::vector<DMatch> lsd_matches;
186 bdm->
match( leftDEscr, rightDescr, lsd_matches );
189 good_matches.clear();
190 for (
int i = 0; i < (int) lsd_matches.size(); i++ )
192 if( lsd_matches[i].distance < MATCHES_DIST_THRESHOLD )
193 good_matches.push_back( lsd_matches[i] );
198 resize( imageMat1, imageMat1,
Size( imageMat1.cols / 2, imageMat1.rows / 2 ) );
199 resize( imageMat2, imageMat2,
Size( imageMat2.cols / 2, imageMat2.rows / 2 ) );
200 std::vector<char> lsd_mask( matches.size(), 1 );
204 imshow(
"LSD matches", lsd_outImg );
void detect(const Mat &image, std::vector< KeyLine > &keypoints, int scale, int numOctaves, const Mat &mask=Mat())
Detect lines inside an image.
bool imwrite(const String &filename, InputArray img, const std::vector< int > ¶ms=std::vector< int >())
Saves an image to a specified file.
Mat row(int y) const
Creates a matrix header for the specified matrix row.
static Ptr< LSDDetector > createLSDDetector()
Creates ad LSDDetector object, using smart pointers.
static Ptr< BinaryDescriptor > createBinaryDescriptor()
Create a BinaryDescriptor object with default parameters (or with the ones provided) and return a sma...
void push_back(const _Tp &elem)
Adds elements to the bottom of the matrix.
Mat imread(const String &filename, int flags=IMREAD_COLOR)
Loads an image from a file.
static MatExpr ones(int rows, int cols, int type)
Returns an array of all 1's of the specified size and type.
uchar * data
pointer to the data
Definition: mat.hpp:1909
void imshow(const String &winname, InputArray mat)
Displays an image in the specified window.
Definition: affine.hpp:51
Designed for command line parsing.
Definition: utility.hpp:734
Definition: descriptor.hpp:1318
MatSize size
Definition: mat.hpp:1926
void drawLineMatches(const Mat &img1, const std::vector< KeyLine > &keylines1, const Mat &img2, const std::vector< KeyLine > &keylines2, const std::vector< DMatch > &matches1to2, Mat &outImg, const Scalar &matchColor=Scalar::all(-1), const Scalar &singleLineColor=Scalar::all(-1), const std::vector< char > &matchesMask=std::vector< char >(), int flags=DrawLinesMatchesFlags::DEFAULT)
Draws the found matches of keylines from two images.
Definition: descriptor.hpp:77
Template class for smart pointers with shared ownership.
Definition: cvstd.hpp:280
Size2i Size
Definition: types.hpp:313
#define CV_8UC1
Definition: interface.h:82
static Scalar_< double > all(double v0)
returns a scalar with all elements set to v0
Definition: cvstd.hpp:477
n-dimensional dense array class
Definition: mat.hpp:740
void match(const Mat &queryDescriptors, const Mat &trainDescriptors, std::vector< DMatch > &matches, const Mat &mask=Mat()) const
For every input query descriptor, retrieve the best matching one from a dataset provided from user or...
static Ptr< BinaryDescriptorMatcher > createBinaryDescriptorMatcher()
Create a BinaryDescriptorMatcher object and return a smart pointer to it.
int waitKey(int delay=0)
Waits for a pressed key.
In the above example, the closest 6 descriptors are returned for every query. In some cases, we could have a search radius and look for all descriptors distant at the most r from input query. Previous code must me modified:
Here's an example om matching among descriptors extratced from original cameraman image and its downsampled (and blurred) version:
55 static const std::string images[] =
56 {
"cameraman.jpg",
"church.jpg",
"church2.png",
"einstein.jpg",
"stuff.jpg" };
58 static const char* keys =
59 {
"{@image_path | | Image path }" };
63 std::cout <<
"\nThis example shows the functionalities of radius matching " <<
"Please, run this sample using a command in the form\n" 64 <<
"./example_line_descriptor_radius_matching <path_to_input_images>/" << std::endl;
67 int main(
int argc,
char** argv )
74 int num_elements =
sizeof ( images ) /
sizeof ( images[0] );
75 std::vector < Mat > descriptorsMat;
76 std::vector < std::vector<KeyLine> > linesMat;
82 for (
int i = 0; i < num_elements; i++ )
85 std::stringstream image_path;
86 image_path << pathToImages << images[
i];
87 std::cout << image_path.str().
c_str() << std::endl;
90 Mat loadedImage =
imread( image_path.str().c_str(), 1 );
91 if( loadedImage.
data == NULL )
93 std::cout <<
"Could not load images." << std::endl;
99 std::vector < KeyLine > lines;
101 bd->
detect( loadedImage, lines );
102 bd->
compute( loadedImage, lines, computedDescr );
104 descriptorsMat.push_back( computedDescr );
105 linesMat.push_back( lines );
111 for (
size_t j = 0; j < descriptorsMat.size(); j++ )
113 if( descriptorsMat[j].rows >= 5 )
114 queries.
push_back( descriptorsMat[j].rowRange( 0, 5 ) );
116 else if( descriptorsMat[j].rows > 0 && descriptorsMat[j].rows < 5 )
120 std::cout <<
"It has been generated a matrix of " << queries.
rows <<
" descriptors" << std::endl;
126 bdm->
add( descriptorsMat );
129 std::vector < std::vector<DMatch> > matches;
131 std::cout <<
"size matches sample " << matches.size() << std::endl;
133 for (
int i = 0; i < (int) matches.size(); i++ )
135 for (
int j = 0; j < (int) matches[i].size(); j++ )
137 std::cout <<
"match: " << matches[
i][j].queryIdx <<
" " << matches[
i][j].trainIdx <<
" " << matches[
i][j].distance << std::endl;
static Ptr< BinaryDescriptor > createBinaryDescriptor()
Create a BinaryDescriptor object with default parameters (or with the ones provided) and return a sma...
int rows
the number of rows and columns or (-1, -1) when the matrix has more than 2 dimensions ...
Definition: mat.hpp:1907
void push_back(const _Tp &elem)
Adds elements to the bottom of the matrix.
Mat imread(const String &filename, int flags=IMREAD_COLOR)
Loads an image from a file.
uchar * data
pointer to the data
Definition: mat.hpp:1909
Definition: affine.hpp:51
Designed for command line parsing.
Definition: utility.hpp:734
void add(const std::vector< Mat > &descriptors)
Store locally new descriptors to be inserted in dataset, without updating dataset.
const char * c_str() const
Definition: descriptor.hpp:77
Template class for smart pointers with shared ownership.
Definition: cvstd.hpp:280
void detect(const Mat &image, std::vector< KeyLine > &keypoints, const Mat &mask=Mat())
Requires line detection.
void compute(const Mat &image, std::vector< KeyLine > &keylines, Mat &descriptors, bool returnFloatDescr=false) const
Requires descriptors computation.
for i
Definition: modelConvert.m:63
void radiusMatch(const Mat &queryDescriptors, const Mat &trainDescriptors, std::vector< std::vector< DMatch > > &matches, float maxDistance, const Mat &mask=Mat(), bool compactResult=false) const
For every input query descriptor, retrieve, from a dataset provided from user or from the one interna...
Definition: cvstd.hpp:477
static Ptr< BinaryDescriptorMatcher > createBinaryDescriptorMatcher()
Create a BinaryDescriptorMatcher object and return a smart pointer to it.