Wednesday, March 23, 2016

opencv_annotation code

/*****************************************************************************************************

USAGE:

./opencv_annotation -images -annotations






Created by: Puttemans Steven

*****************************************************************************************************/



#include

#include

#include

#include

#include

#include

#include

using namespace std;

using namespace cv;




// Function prototypes


void on_mouse(int, int, int, int, void*);

string int2string(int);

bool get_annotations(Mat, stringstream*);




// Public parameters


Mat image;

int roi_x0 = 0, roi_y0 = 0, roi_x1 = 0, roi_y1 = 0, num_of_rec = 0;

bool start_draw = false;




// Window name for visualisation purposes


const string window_name="OpenCV Based Annotation Tool";




// FUNCTION : Mouse response for selecting objects in images

// If left button is clicked, start drawing a rectangle as long as mouse moves

// Stop drawing once a new left click is detected by the on_mouse function


void on_mouse(int event, int x, int y, int , void * )



{

// Action when left button is clicked

if(event == EVENT_LBUTTONDOWN)



{

if(!start_draw)



{

roi_x0 = x;

roi_y0 = y;

start_draw = true;

} else {

roi_x1 = x;

roi_y1 = y;

start_draw = false;



}

}

// Action when mouse is moving

if((event == EVENT_MOUSEMOVE) && start_draw)



{

// Redraw bounding box for annotation

Mat current_view;



image.copyTo(current_view);

rectangle(current_view, Point(roi_x0,roi_y0), Point(x,y), Scalar(0,0,255));



imshow(window_name, current_view);

}

}

// FUNCTION : snippet to convert an integer value to a string using a clean function

// instead of creating a stringstream each time inside the main code


string int2string(int num)



{

stringstream temp_stream;

temp_stream << num;

return temp_stream.str();



}

// FUNCTION : given an image containing positive object instances, add all the object

// annotations to a known stringstream


bool get_annotations(Mat input_image, stringstream* output_stream)



{

// Make it possible to exit the annotation

bool stop = false;

// Reset the num_of_rec element at each iteration

// Make sure the global image is set to the current image



num_of_rec = 0;

image = input_image;

// Init window interface and couple mouse actions

namedWindow(window_name, WINDOW_AUTOSIZE);



setMouseCallback(window_name, on_mouse);

imshow(window_name, image);

stringstream temp_stream;

int key_pressed = 0;

do



{

// Keys for processing

// You need to select one for confirming a selection and one to continue to the next image

// Based on the universal ASCII code of the keystroke: http://www.asciitable.com/

// c = 99 add rectangle to current image

// n = 110 save added rectangles and show next image

// = 27 exit program



key_pressed = 0xFF & waitKey(0);

switch( key_pressed )



{

case 27:



destroyWindow(window_name);

stop = true;

case 99:

// Add a rectangle to the list



num_of_rec++;

// Draw initiated from top left corner

if(roi_x0



{

temp_stream << " " << int2string(roi_x0) << " " << int2string(roi_y0) << " " << int2string(roi_x1-roi_x0) << " " << int2string(roi_y1-roi_y0);



}

// Draw initiated from bottom right corner

if(roi_x0>roi_x1 && roi_y0>roi_y1)



{

temp_stream << " " << int2string(roi_x1) << " " << int2string(roi_y1) << " " << int2string(roi_x0-roi_x1) << " " << int2string(roi_y0-roi_y1);



}

// Draw initiated from top right corner

if(roi_x0>roi_x1 && roi_y0



{

temp_stream << " " << int2string(roi_x1) << " " << int2string(roi_y0) << " " << int2string(roi_x0-roi_x1) << " " << int2string(roi_y1-roi_y0);



}

// Draw initiated from bottom left corner

if(roi_x0roi_y1)



{

temp_stream << " " << int2string(roi_x0) << " " << int2string(roi_y1) << " " << int2string(roi_x1-roi_x0) << " " << int2string(roi_y0-roi_y1);



}

rectangle(input_image, Point(roi_x0,roi_y0), Point(roi_x1,roi_y1), Scalar(0,255,0), 1);

break;



}

// Check if escape has been pressed

if(stop)



{

return false;



}

}

// Continue as long as the next image key has not been pressed

while(key_pressed != 110);

// If there are annotations AND the next image key is pressed

// Write the image annotations to the file

if(num_of_rec>0 && key_pressed==110)



{

*output_stream << " " << num_of_rec << temp_stream.str() << endl;



}

// Close down the window



destroyWindow(window_name);

return true;



}

int main( int argc, const char** argv )



{

// If no arguments are given, then supply some information on how this tool works

if( argc == 1 ){

cout << "Usage: " << argv[0] << endl;

cout << " -images [example - /data/testimages/]" << endl;

cout << " -video [example - /data/video.mp4/]" << endl;

cout << " -annotations [example - /data/annotations.txt]" << endl;

return -1;



}

// Read in the input arguments

string image_folder;

string annotations;

string video_file;

bool image_annotation = false;

bool video_annotation = false;

for(int i = 1; i < argc; ++i )



{

if( !strcmp( argv[i], "-images" ) )



{

image_folder = argv[++i];

image_annotation = true;



}

else if( !strcmp( argv[i], "-annotations" ) )



{

annotations = argv[++i];



}

else if( !strcmp( argv[i], "-videos" ) )



{

video_file = argv[++i];

video_annotation = true;



}

}

// Create the outputfilestream

ofstream output(annotations.c_str());

if(image_annotation)



{

// Return the image filenames inside the image folder

vector<String> filenames;

String folder(image_folder);



glob(folder, filenames);

// Loop through each image stored in the images folder

// Create and temporarily store the annotations

// At the end write everything to the annotations file

for (size_t i = 0; i < filenames.size(); i++){

// Read in an image

Mat current_image = imread(filenames[i]);

// Perform annotations & generate corresponding output

stringstream output_stream;



get_annotations(current_image, &output_stream);

// Store the annotations, write to the output file

if (output_stream.str() != ""){



output << filenames[i] << output_stream.str();

}

}

}

if(video_annotation)



{

VideoCapture cap(video_file);

if(!cap.isOpened())



{

cout << "could not open the video file"<

return -1;



}

int frame_no = 0;





while(1)



{

// Read in an image

Mat current_image;

bool bSuccess = cap.read(current_image);

if(!bSuccess)



{

cout << "cannot read the frames from the video file" <

break;



}

// Perform annotations & generate corresponding output

stringstream output_stream;

bool success = get_annotations(current_image, &output_stream);

if(!success)

break;

// Store the annotations, write to the output file

if (output_stream.str() != ""){

output << "frame_number = " << frame_no++ << ":" << output_stream.str();



}

}

}

return 0;



}

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