I want to load an image with opencv. Everything is working properly but it doesn't show me the image. Code what I usin is here:
#include
#include
#include
using namespace cv;
using namespace std;
int main( int argc, const char** argv )
{
IplImage *img = cvLoadImage("D:/C++/ MGC.JPG");
cvNamedWindow("MyWindow", 1); //create a window with the name "MyWindow"
cvMoveWindow("MyWindow", 100, 100);
cvShowImage("MyWindow", img);
cvWaitKey(0); //wait infinite time for a keypress
cvDestroyWindow("MyWindow"); //destroy the window with the name, "MyWindow"
return 0;
}
Is there a specific reason you chose to use the C interface? If not, you should be using the C++ interface
int main( int argc, const char** argv )
{
cv::Mat image = cv::imread("D:/C++/ MGC.JPG");
cv::namedWindow("MyWindow", 256);
cv::imshow("MyWindow", image );
cv::waitKey();
return 0;
}
Related
I'm trying to get the stream and defining the ROI and tracking an object within ROI using dlib correlation tracker but there is a error in compilation, not found any code or explanation which can describe any solution of this error. Thanks in advance.
cvcap.cpp
#include <stdio.h>
#include <opencv2/opencv.hpp>
#include "dlib/image_processing.h"
#include "dlib/gui_widgets.h"
#include "dlib/image_io.h"
#include "dlib/dir_nav.h"
using namespace dlib;
using namespace std;
int main(int argc, char * argv[]){
CvCapture* camera = cvCaptureFromFile(argv[1]);
if (camera==NULL)
printf("camera is null\n");
else
printf("camera is not null\n");
cvNamedWindow("CvCapture");
while (cvWaitKey(1000)!=atoi("q")){
double t1 = (double)cvGetTickCount();
IplImage *img = cvQueryFrame(camera);
cvSetImageROI(img, cvRect(140, 150, 340, 150));
IplImage *img1 = cvCreateImage(cvGetSize(img), img->depth, img->nChannels);
cvCopy(img, img1, NULL);
cvResetImageROI(img);
cvShowImage("ROI",img1);
correlation_tracker tracker;
tracker.start_track(img1, centered_rect(point(120,100), 80, 150));
image_window win;
tracker.update(img1);
win.set_image(img1);
win.clear_overlay();
win.add_overlay(tracker.get_position());
cout << "hit enter to process next frame" << endl;
cin.get();
double t2=(double)cvGetTickCount();
printf("time: %gms fps: %.2g\n",(t2-t1)/(cvGetTickFrequency()*1000.), 1000./((t2-t1)/(cvGetTickFrequency()*1000.)));
cvShowImage("CvCapture",img1);
}
cvReleaseCapture(&camera);
}
the error is :
In file included from dlib/image_processing.h:24:0,
from cvcap.cpp:3:
dlib/image_processing/correlation_tracker.h: In instantiation of ‘dlib::point_transform_affine dlib::correlation_tracker::make_chip(const image_type&,
dlib::drectangle, std::vector<dlib::matrix<std::complex<double> > >&) const [with image_type = _IplImage*]’:
dlib/image_processing/correlation_tracker.h:65:47: required from ‘void dlib::correlation_tracker::start_track(const image_type&, const dlib::drectang
le&) [with image_type = _IplImage*]’
cvcap.cpp:36:70: required from here
dlib/image_processing/correlation_tracker.h:301:67: error: invalid use of incomplete type ‘struct dlib::image_traits<_IplImage*>’
typedef typename image_traits<image_type>::pixel_type pixel_type;
Update
i edited my code and now it is compiling but when i'm running my code, tracking box appears but it is not tracking the objects.
for(;;) {
if(!vcap.read(image)) {
std::cout << "No frame" << std::endl;
break;
} else {
std::cout << "Starting" << std::endl;
array2d<rgb_pixel> img;
assign_image(img, cv_image<rgb_pixel>(image));
tracker.start_track(img, centered_rect(point(413,260), 98, 126));
for (unsigned long i = 0; i < img.size(); i++) {
tracker.update(img);
win.set_image(img);
win.clear_overlay();
win.add_overlay(tracker.get_position());
}
}
}
You're passing an IplImage to the dlib routine. But if you look at the docs it says you have to convert your opencv images to cv_images before passing them to dlib functions. And you can see this with the error pointing out IplImage doesn't have a pixel_type trait. A fix would be.
IplImage *img1 = cvCreateImage(cvGetSize(img), img->depth, img->nChannels);
...
correlation_tracker tracker;
// Not sure if the tracker wants a single channel image
// change rgb_alpha_pixel to uchar in that case.
tracker.start_track(dlib::cv_image<dlib::rgb_alpha_pixel>(img1), centered_rect(point(120,100), 80, 150));
Pixel types and the Correlation tracker
EDIT: Passed your stuff to opencv 3 and this is compiling for me. Do you really need to use opencv 2?
#include <stdio.h>
#include <opencv2/opencv.hpp>
#include "dlib/image_processing.h"
#include "dlib/gui_widgets.h"
#include "dlib/image_io.h"
#include "dlib/dir_nav.h"
#include <dlib/opencv/cv_image.h>
using namespace cv;
using namespace dlib;
using namespace std;
int main(int argc, char * argv[]){
VideoCapture cap(0);
Mat frame;
while (cap.read(frame)) {
cvtColor(frame, frame, CV_RGB2GRAY);
cv_image<unsigned char> img(frame);
correlation_tracker tracker;
tracker.start_track(img, centered_rect(point(120,100), 80, 150));
image_window win;
tracker.update(img);
win.set_image(img);
win.clear_overlay();
win.add_overlay(tracker.get_position());
cout << "hit enter to process next frame" << endl;
cv::waitKey(0);
}
}
and with an uglier opencv 2..
#include <stdio.h>
#include <opencv2/opencv.hpp>
#include "dlib/image_processing.h"
#include "dlib/gui_widgets.h"
#include "dlib/image_io.h"
#include "dlib/dir_nav.h"
#include <dlib/opencv/cv_image.h>
using namespace cv;
using namespace dlib;
using namespace std;
int main(int argc, char * argv[]){
CvCapture* camera = cvCaptureFromFile(argv[1]);
if (camera==NULL)
printf("camera is null\n");
else
printf("camera is not null\n");
cvNamedWindow("CvCapture");
while (cvWaitKey(1000)!=atoi("q")) {
double t1 = (double)cvGetTickCount();
IplImage *img = cvQueryFrame(camera);
cvSetImageROI(img, cvRect(140, 150, 340, 150));
IplImage *img1 = cvCreateImage(cvGetSize(img), img->depth, img->nChannels);
cvCopy(img, img1, NULL);
cvResetImageROI(img);
cvShowImage("ROI",img1);
cvCvtColor(img1, img1, CV_RGB2GRAY);
cv_image<unsigned char> img2(img1);
correlation_tracker tracker;
tracker.start_track(img2, centered_rect(point(120,100), 80, 150));
image_window win;
tracker.update(img2);
win.set_image(img2);
win.clear_overlay();
win.add_overlay(tracker.get_position());
cout << "hit enter to process next frame" << endl;
cin.get();
double t2=(double)cvGetTickCount();
printf("time: %gms fps: %.2g\n",(t2-t1)/(cvGetTickFrequency()*1000.), 1000./((t2-t1)/(cvGetTickFrequency()*1000.)));
cvShowImage("CvCapture",img1);
}
cvReleaseCapture(&camera);
}
As you see the error came exactly from what I told you before.
I have recently used this piece of code to save frame data from a webcam
#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <opencv2/opencv.hpp>
using namespace cv;
#include <fstream>
using namespace std;
int main(int argc, char** argv)
{
VideoCapture cap(0); // open the default camera
if (!cap.isOpened()) // check if we succeeded
return -1;
cap.set(CV_CAP_PROP_FPS, 15);
Mat edges;
namedWindow("image", 1);
std::vector<cv::Mat> images(100);
for (int i = 0; i < 100; ++i) {
// this is optional, preallocation so there's no allocation
// during capture
images[i].create(480, 640, CV_8UC3);
}
for (int i = 0; i < 100; ++i)
{
Mat frame;
cap >> frame; // get a new frame from camera
frame.copyTo(images[i]);
}
cap.release();
for (int i = 0; i < 100; ++i)
{
imshow("image", images[i]);
if (waitKey(30) >= 0) break;
}
After this, I want to use imread to analyse the newly splitted frames. However, I cannot think of a way to accomplish this.
I tried: Mat colorImage = imread(images[i]);
However, it leads to:
error C2664: 'cv::Mat cv::imread(const cv::String &,int)': cannot convert argument 1 from 'std::vector<cv::Mat,std::allocator<_Ty>>' to 'const cv::String &'
with
[
_Ty=cv::Mat
]
Thanks a lot in advance :)
imread function is used to open the image from disk.
You already have vector of images so you just do:
Mat colorImage = images[i];
and btw. there is no need for this:
for (int i = 0; i < 100; ++i) {
// this is optional, preallocation so there's no allocation
// during capture
images[i].create(480, 640, CV_8UC3);
}
because you are allocating new space anyway except you capture the frames directly like this:
cap >> images[i];
I am having doubt in opencv. I'm trying to implement SURF algorithm. When I trying to build the code but I'm getting the following error.
*****error LNK2019: unresolved external symbol _cvExtractSURF referenced in function _main
1>SAMPLE.obj : error LNK2019: unresolved external symbol _cvSURFParams referenced in function _main*****
I have gone through all the posts related to my topic in this forum, but couldn't figure out the problem with my code. Please help me in resolving my problem.
code :
#include <stdio.h>
#include <opencv2/features2d/features2d.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc_c.h>
#include <opencv2\objdetect\objdetect.hpp>
#include <opencv2\calib3d\calib3d.hpp>
#include <opencv2\core\core.hpp>
#include <opencv2\legacy\legacy.hpp>
#include <opencv2\legacy\compat.hpp>
#include <opencv2/nonfree/nonfree.hpp>
#include <opencv\opensurf\surf.h>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
CvMemStorage* storage = cvCreateMemStorage(0);
cvNamedWindow("Image", 1);
int key = 0;
static CvScalar red_color[] ={0,0,255};
IplImage* capture= cvLoadImage( "testface.jpg");
CvMat* prevgray = 0, *image = 0, *gray =0;
while( key != 'q' )
{
int firstFrame = gray == 0;
IplImage* frame =capture;
if(!frame)
break;
if(!gray)
{
image = cvCreateMat(frame->height, frame->width, CV_8UC1);
}
//Convert the RGB image obtained from camera into Grayscale
cvCvtColor(frame, image, CV_BGR2GRAY);
//Define sequence for storing surf keypoints and descriptors
CvSeq *imageKeypoints = 0, *imageDescriptors = 0;
int i;
//Extract SURF points by initializing parameters
CvSURFParams params = cvSURFParams(500,1);
cvExtractSURF( image, 0, &imageKeypoints, &imageDescriptors, storage, params );
printf("Image Descriptors: %d\n", imageDescriptors->total);
//draw the keypoints on the captured frame
for( i = 0; i < imageKeypoints->total; i++ )
{
CvSURFPoint* r = (CvSURFPoint*)cvGetSeqElem( imageKeypoints, i );
CvPoint center;
int radius;
center.x = cvRound(r->pt.x);
center.y = cvRound(r->pt.y);
radius = cvRound(r->size*1.2/9.*2);
cvCircle( frame, center, radius, red_color[0], 1, 8, 0 );
}
cvShowImage( "Image", frame );
cvWaitKey(0);
}
cvDestroyWindow("Image");
return 0
}
Thank you,
Sreelakshmi Priya
Can any one tell what wrong with the below code. I am getting segmentation fault while mouse moving last portion of the image. I am just printing R,G,B value according to the mouse position.
#include <iostream>
#include <stdio.h>
#include <opencv2/opencv.hpp>
using namespace cv;
using namespace std;
Mat image;
char window_name[20]="Pixel Value Demo";
static void onMouse( int event, int x, int y, int f, void* ){
Vec3b pix=image.at<Vec3b>(x,y);
int B=pix.val[0];
int G=pix.val[1];
int R=pix.val[2];
cout<<R<<endl<<G<<endl<<B<<endl;
}
int main( int argc, char** argv )
{
namedWindow( window_name, CV_WINDOW_AUTOSIZE );
image = imread( "src.jpg");
imshow( window_name, image );
setMouseCallback( window_name, onMouse, 0 );
waitKey(0);
return 0;
}
Thanks in advance......
Vec3b pix=image.at<Vec3b>(x,y);
should be :
Vec3b pix=image.at<Vec3b>(y,x); // row,col !!
I have configure all the libraries and path required for running open cv in c/c++ mode in eclipse, i have written the below code, but i don't know how to build and debug,
my code is
#include "cv.h"
#include "highgui.h"
//using namespace cv;
int main(int argc, char *argv[])
{
cvNamedWindow( "Example1", CV_WINDOW_AUTOSIZE );
IplImage* img = cvLoadImage("prado.jpg",1);
cvShowImage("Example1", img );//*/
cvWaitKey(0);
return 0;
}