This is what my code looks like, I got the undefined reference to imread and so on:
#include <iostream>
#include <opencv2/opencv.hpp>
using namespace std;
using namespace cv;
int main( int argc, const char** argv )
{
Mat img = imread("MyPicture.jpg", CV_LOAD_IMAGE_UNCHANGED); //read the image data in the file "MyPic.JPG" and store it in 'img'
if (img.empty()) //check whether the image is loaded or not
{
cout << "Error : Image cannot be loaded..!!" << endl;
//system("pause"); //wait for a key press
return -1;
}
namedWindow("MyWindow", CV_WINDOW_AUTOSIZE); //create a window with the name "MyWindow"
imshow("MyWindow", img); //display the image which is stored in the 'img' in the "MyWindow" window
waitKey(0); //wait infinite time for a keypress
destroyWindow("MyWindow"); //destroy the window with the name, "MyWindow"
return 0;
}
I am using Codeblocks and the g++ compiler. Also I have linked the opencv_world310d.lib to debug and opencv_world310.lib to release.
Plus I have given the path in searchdirectory compiler and linker.
Any hints?
Related
The code is:
#include <iostream>
#include <opencv2/opencv.hpp>
int main (int argc, char** argv) {
auto path = "C:/Users/huhua/Pictures/11.jpg";
auto img = cv::imread(path);
if (img.empty()) {
std::cout << "is empty" << std::endl;
return 1;
}
cv::imshow("demo", img);
cv::waitKey(0);
return 0;
}
The 11.jpg exist. And if I use another 11.bmp. It works well.
After debug. The error is throw at libjpeg-trubo/src/jdatasr.c
fill_input_buffer(j_decompress_ptr cinfo)
{
my_src_ptr src = (my_src_ptr)cinfo->src;
size_t nbytes;
// error is throw at here
nbytes = JFREAD(src->infile, src->buffer, INPUT_BUF_SIZE);
// ...
}
Is my libjpeg issue??
How to fix this?
The 11.jpg image:
Update:
The OpenCV info
Update on 2021/10/19:
The reason is I set the cmake_toolchain_path after project(xxx). I should set the cmake_toolchain_path before project.
https://github.com/microsoft/vcpkg/discussions/20802
I know this question has been asked a number of times and I'm trying to implement their answers but its causing an exception in my code.
OS: Windows 7
OpenCV: 2.4.9
Here is my code:
#include "stdafx.h"
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
using namespace cv;
using namespace std;
int main( int argc, char** argv )
{
VideoCapture cap(0); //capture the video from webcam
if ( !cap.isOpened() ) // if not success, exit program
{
cout << "Cannot open the web cam" << endl;
return -1;
}
Mat imgHSV;
_sleep(100); //give the camera a chance to wake up
while (true)
{
Mat imgOriginal;
bool success = cap.read(imgOriginal);
if (!success) //if not success, break loop
{
cout << "Cannot read a frame from video stream" << endl;
break;
}
cvtColor(imgOriginal, imgHSV, COLOR_BGR2HSV); //Convert the captured frame from BGR to HSV
vector<Mat> hsv_planes;
split( imgHSV, hsv_planes );
//hsv_planes[0] // H channel
//hsv_planes[1] // S channel
//hsv_planes[2] // V channel
imshow(thresholded_window, hsg_planes[2]); //show the S channel
if (waitKey(30) == 27) //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
{
cout << "esc key is pressed by user" << endl;
break;
}
}
return 0;
}
Exception is thrown on the split line: "Unhandled exception at 0x62B978C9 (opencv_core249.dll) in TrackColour.exe: 0xC0000005: Access violation writing location 0xFEEEFEEE."
I figured out my problem, incase this happens to anyone else.
In VS I was doing a debug build but I was linking to the non debug versions of opencv. Notice in my error message opencv_core249, it should have been opencv_core249d (Note the 'd'). I updated my CV linking to use the debug libraries and it works.
The other opencv calls performed fine using the wrong libraries, something must be unique with split.
I'm running this code:
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
using namespace cv;
using namespace std;
int main( int argc, char** argv ) {
if( argc != 2)
{
cout <<" Usage: display_image ImageToLoadAndDisplay" << endl;
return -1;
}
Mat image;
image = imread(argv[1], CV_LOAD_IMAGE_COLOR); // Read the file
if(! image.data ) // Check for invalid input
{
cout << "Could not open or find the image" << std::endl ;
return -1;
}
namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
imshow( "Display window", image ); // Show our image inside it.
waitKey(0); // Wait for a keystroke in the window
return 0; }
But it isn't working for me because it shows this error on my screen when I write cmake . in terminal:
cv.h: file not found.
Could anyone help me? It was working one month ago.
you have linking problem, try this out;
g++ `pkg-config --cflags --libs opencv` filename.cpp -o filename
You can change the linker properties in case of Visual studio.
For Makefile you need to make sure that the opencv_dir is set correctly.
Newbie question and yes I have spent a lot of time sifting through similar questions and Answers with no luck.
What I am trying to do is save frames from a video file in a sequential order. I have managed to save one image using c and I cannot seem to save images after that. I have started using c++ in opencv instead of c and all I can do is view the video and not save any jpg's from it.
I am using opencv2.4.4a on mac if that helps.
below is my c example
#include <stdio.h>
#include <stdlib.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <iostream>
using namespace cv;
using namespace std;
int main (int argc, char** argv)
{
//initializing capture from file
CvCapture * capture = cvCaptureFromAVI ("/example/example.mov");
//Capturing a frame
IplImage* img = 0;
if(!cvGrabFrame(capture)) //capture a frame
{
printf)Could not grab a fram\n\7");
exit(0);
}
img=cvRerieveFrame(capture); //retrieve the captured frame
//writing an image to a file
if (!cvSaveImage("/frames/test.jpg", img))
printf("Could not save: %s\n","test.jpg");
//free resources
cvReleaseCapture(&capture);
}
Thank you in advance
edit to the above.
I have added to the above code which results in an image to be saved with the test.jpg and then gets rewritten with the next frame. How do I tell opencv to not copy over the last image and rename the next frame to test_2.jpg eg, test_1.jpg, test_2.jpg and so on?
double num_frames = cvGetCaptureProperty (capture, CV_CAP_PROP_FRAME_COUNT);
for (int i = 0; i < (int)num_frames; i++)
{
img = cvQueryFrame(capture);
cvSaveImage("frames/test.jpg", img);
}
cvReleaseCapture(&capture);
}
This is my code... I tryed a lot and finally made it
this is c++ using opencv 3... hope it works
#include "opencv2/opencv.hpp"
#include <sstream>
#include <iostream>
using namespace cv;
using namespace std;
Mat frame,img;
int counter;
int main(int,char**)
{
VideoCapture vid("video3.avi");
while (!vid.isOpened())
{
VideoCapture vid("video2.MOV");
cout << "charging" << endl;
waitKey(1000);
}
cout << "Video opened!" << endl;
while(1)
{
stringstream file;
vid.read(frame);
if(frame.empty()) break;
file << "/home/pedro/workspace/videoFrame/Debug/frames/image" << counter << ".jpg";
counter++;
imwrite(file.str(),frame);
char key = waitKey(10);
if ( key == 27)
{break;}
}
}
Use an index that will keep track of the number part in the filename. In the image capturing loop, add the index with the filename and build the final filename.
here is an example :
while(1)
{
cap.read ( frame);
if( frame.empty()) break;
imshow("video", frame);
char filename[80];
sprintf(filename,"C:/Users/cssc/Desktop/testFolder/test_%d.png",i);
imwrite(filename, frame);
i++;
char key = waitKey(10);
if ( key == 27) break;
}
This is my way to do in Python3.0. Have to have CV2 3+ version for it to work.
This function saves images with frequency given.
import cv2
import os
print(cv2.__version__)
# Function to extract frames
def FrameCapture(path,frame_freq):
# Path to video file
video = cv2.VideoCapture(path)
success, image = video.read()
# Number of frames in video
fps = int(video.get(cv2.CAP_PROP_FPS))
length = int(video.get(cv2.CAP_PROP_FRAME_COUNT))
print('FPS:', fps)
print('Extracting every {} frames'.format(frame_freq))
print('Total Frames:', length)
print('Number of Frames Saved:', (length // frame_freq) + 1)
# Directory for saved frames
try:
frame_dir = path.split('.')[0]
os.mkdir(frame_dir)
except FileExistsError:
print('Directory ({}) already exists'.format(frame_dir))
# Used as counter variable
count = 0
# checks whether frames were extracted
success = 1
# vidObj object calls read
# function extract frames
while count < length :
video.set(cv2.CAP_PROP_POS_FRAMES , count)
success, image = video.read()
# Saves the frames with frame-count
cv2.imwrite(frame_dir + "/frame%d.jpg" % count, image)
count = count + frame_freq
I am running my below code in eclipse, i have include the path and libraries successfuly, but when run the code it shows an error.
#include <cv.h>
#include<stdio.h>
#include <highgui.h>
//using namespace cv;
int main()
{
Mat image;
image = imread( argv[1], 1 );
if( argc != 2 || !image.data )
{
printf( "No image data \n" );
return -1;
}
namedWindow( "Display Image", CV_WINDOW_AUTOSIZE );
imshow( "Display Image", image );
waitKey(0);
printf("this is open cv programming");
return 0;
}
Your main() signature is incomplete
try
int main(int argc, char* argv[])
these parameters represent:
argc // an int indicating the number of arguments passed in to the function
argv[] // an array of character strings, the actual arguments.
The first argument argv[0] is the program name ... so argc is always a minimum of 1.
The second argument, argv[1] will be the first argument your user passes in, bringing argc up to 2. That is what your program is expecting, a single argument from the user, argc == 2.
Try to use the latest version of OpenCV i.e. 2.4.3....however right now you can try to link the debug libraries e.g. opencv_core2.4.xd and run the program to get the Mat image format working.
what is the version of opencv you are using?
try the following code and test...get some picture and run it....
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;
int main()
{
Mat im = imread("C:\\some_picture.jpg");
if(im.empty())
return -1;
imshow("TEST",im);
waitKey();
return 0;
}