I wrote code to embed opencv window in picture box in MFC. The successful state should be opencv window in the MFC and display pics in MFC. However, my code still make the opencv window flowing around. And I can't find where the problem would be. Any one can help me out?
I will appreciate it.
BOOL SENSEIDlg_XQ::OnInitDialog(){
CDialog::OnInitDialog();
namedWindow("VIDEO",0);
HWND hWnd_video = (HWND)cvGetWindowHandle("VIDEO");
::SetParent(hWnd_video,GetDlgItem(IDC_STATIC_PIC1)->m_hWnd);
HWND video_parent = ::GetParent(hWnd_video);
::ShowWindow(video_parent,SW_HIDE);
return TRUE;
The IDC_STATIC_PIC1 is a picture box in a Cdialog.
I've already figured it out. Write out the solutions for other users who may bump into the same problems. change namedWindow into cvNamedWindow. Apparently, C library is better than C++ here. If you guys bump into the same problem try this.
Related
I am trying to use C++ AMP in Visual C++ 2017 on Windows 10 (updated to the latest) and I find the archived FFT library from C++ AMP team on codeplex. I try to run the sample code, however the program throws ran out of memory error when creating DirectX FFT. I solve that problem by following the thread on Microsoft forum.
However, the problem doesn't stop. When the FFT library tries to create Unordered Access View, it throws error of CLIPBRD_E_CANT_OPEN. I did not try to operate on clipboard anyhow.
Thank you for reading this!
It seems I solve the problem. The original post mentioned that we need to create a new DirectX device and then create accelerator view upon it. Then I pass that view to ctor of fft as the second parameter.
fft(
concurrency::extent<_Dim> _Transform_extent,
const concurrency::accelerator_view& _Av = concurrency::accelerator().default_view,
float _Forward_scale = 0.0f,
float _Inverse_scale = 0.0f)
However, I still have crashes of the CLIPBRD_E_CANT_OPEN.
After reading the code, I realize that I need to create array on that DirectX views too. So I started to change:
array<std::complex<float>,dims> transformed_array(extend, directx_acc_view);
The idea comes from the different behaviors of create_uav(). The internal buffers and the precomputing caused no problem, but the samples' calls trigger the clipboard error. I guess the device matters here, so I do that change.
I hope my understanding is correct and anyway there is no such errors now.
I'm trying to use the OSVR IR camera in OpenCV 3.1.
Initialization works OK.
Green LED is lit on camera.
When I call VideoCapture.read(mat) it returns false and mat is empty.
Other cameras work fine with the same code and VLC can grab the stream from the OSVR camera.
Some further testing reveals: grab() return true, whereas retrieve(mat) again returns false.
Getting width and height from the camera yields expected results but MODE and FORMAT gets me 0.
Is this a config issue? Can it be solved by a combination of VideoCapture.set calls?
Alternative Official answer received from the developers (after my own solution below):
The reason my camera didn't work out of the box with OpenCV might be that it has old firmware (pre-v7).
Work around (or just update firmware):
I found the answer here while browsing anything remotely linked to the issue:
Fastest way to get frames from webcam
You need to specify that it should use DirectShow.
VideoCapture capture( CV_CAP_DSHOW + id_of_camera );
ok, what i am trying to do is retrieve a frame from an existing video file, do some work on the frame and then save it to a new file,
what actually happens is that it writes some frames and then crashes as the code is quite fast,
if i don't put cvWaitKey() i get the same error i get when writing video frames with AVFoundation Library without using
AVAssetWriterInput.readyForMoreMediaData
OpenCV video writer is implemented using AVFoundation classes but we lose access to
AVAssetWriterInput.readyForMoreMediaData
or am i missing something ?
here is the code similar to what i'm trying to do,
while (grabResult&&frameResult) {
grabResult = cvGrabFrame(capture); // capture a frame
if(grabResult){
img = cvRetrieveFrame(capture, 0); // retrieve the captured frame
cvFlip(img,NULL,0); // edit img
frameResult = cvWriteFrame(writer,img); // add the frame to the file
cvWaitKey(-1); or anything that helps to finish adding the previous frame
}
}
I am trying to convert a video file using OpenCV (without displaying)
in my iPhone/iPad app, everything works except cvWaitKey() function
and I get this error:
OpenCV Error: Unspecified error (The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script) in cvWaitKey,
Without this function frames are dropped as there's no way to know if
the video writer is ready, is there an alternative to my problem?
I am using OpenCV 2.4.2 and I get same error with the latest
precompiled version of OpenCV.
Repaint the UIImageView:
[[NSRunLoop currentRunLoop]runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.0f]];
followed by your imshow or cvShowImage
I don't know anything about iOS development, but did you try calling the C++ interface method waitKey()?
I'm trying to use line-mod (in special line-2d) in opencv 2.4 to compare images. At the moment I try to change the test-implementation linemod.cpp to use an input images instead of the camera, but without any success.
I tried to load an image via imread('...', CV_LOAD_IMAGE_COLOR); and pushed that in the sources vector but got a 'OpenCV Error: Assertion failed (response_map.rows % T == 0) in linearize' error.
If I load a CV_LOAD_IMAGE_GRAYSCALE image the run stops at detector->match with the error 'Thread 1: EXC_BAD_ACCESS (code=1, address=0x11310f000)'.
I don't understand what makes the difference between images coming from a VideoCapturer and from imread...
Is there anyone out there that may help me? I'm totally lost ... again ;-)
(For example sample code for matching two objects from images with linemod would be absolutely great!)
I use opencv 2.4 with xcode on a mac.
Maybe it is too late for an answer, but I am also interested in the algorithm
In the OpenCV Minutes 2012-06-26 ( http://code.opencv.org/projects/opencv/wiki/2012 ) you can read:
Will work with Stefan Hinterstoisser for final version of LINEMOD by September
So if you did not already solve it, you may want to wait.
I'm using OpenCV 2.2 with visual studio 2010 on a win 7 64 bit pc.
I'm able to display pictures and play AVI files through OpenCV as given in the book "Learning OpenCV" but I'm not able to capture webcam images. Even the samples given along with the OpenCV files cant access the webcam.
I get asked for " video source -> capture source" and there are two options: HP webcam Splitter and HP webcam. If I select HP webcam the window closes immediately without displaying any error. (i think any error message is too fast to be seen before it closes). If I select HP Webcam splitter then the new window, where the webcam images(video) are supposed to come, is filled with uniform gray. The webcam LED is on but no video is seen. My webcam works fine with flash (www.testmycam.com) and with DirectShow http://www.codeproject.com/KB/audio-video/WebcamUsingDirectShowNET.aspx
I did try getting some error message by using this:
#include "cv.h"
#include "highgui.h"
#include <iostream>
using namespace cv;
using namespace std;
int main(int, char**)
{
VideoCapture cap("0"); // open the default camera
if(!cap.isOpened()) // check if we succeeded
{
cout << "Error opening camera!";
getchar();
return -1;
}
Mat edges;
namedWindow("edges",1);
for(;;)
{
Mat frame;
cap >> frame; // get a new frame from camera
cvtColor(frame, edges, CV_BGR2GRAY);
GaussianBlur(edges, edges, Size(7,7), 1.5, 1.5);
Canny(edges, edges, 0, 30, 3);
imshow("edges", edges);
if(waitKey(30) >= 0) break;
}
// the camera will be deinitialized automatically in VideoCapture destructor
return 0;
}
And the error message I got was:
warning: Error opening file (C:\Users\vp\work\ocv\opencv\modules\highgui\src\cap
_ffmpeg.cpp:454)
Error opening camera!
I don't know what this "cap_ffmpeg.cpp" is and I don't know if this is any issue with the nosy "HP Media Smart" stuff.
Any help will be greatly appreciated.
I had the same issue on Windows 7 64-bit. I had to recompile opencv_highgui changing the "Preprocesser Definitions" in the C/C++ panel of the properties page to include:
HAVE_VIDEOINPUT
HAVE_DSHOW
Hope this helps
The cap_ffmpeg.cpp is the source file which uses ffmpeg to perform capturing of the device. If the default example given from OpenCV doesn't work with your webcam, you are out of luck. I suggest you buy another one that is supported.
Recently I have installed OpenCV 2.2 and NetBeans 6.9.1. I had a problem with camera capture, the image in the window was black but the program runs perfectly, without errors. I had to run NetBeans as admin user to fix this problem.
I hope this can help you all.
I just switched to OpenCV 2.2 and am having essentially the same problem but a 32 bit compture running Vista. The webcam would start but I'd get an error message setting the width property for the camera. If I specifically request the DirectShow camera, the cvCreateCameraCapture would fail.
What I think is going on is that the distribution version of HighGUI was build excluding the DirectShow camera. The favored Windows camera on OpenCV used to be Video For Windows, VFW but that has been deprecated since Windows Vista came out and has created all sorts of problems. Why they don't just include it, I don't know. Check the source file cap.cpp
My next step is to rebuild HighGUI myself and make sure the flag HAVE_DSHOW is set. I seem to remember having the same problem with the last version of OpenCV I've been using until I rebuilt it making sure the DirectShow version was enabled.
I experienced the same problem. My Vaio Webcam LED is on but no image on the screen.
Then I tried to export the first frame to a JPEG file and its working. Then I tried to insert a delay of 33ms before capture any frame, this time it works like a charm. Hope this'll help.
Here's an article I wrote some time back. It uses the videoInput library to get input from webcams. It uses DirectX, so it works with almost every webcam out there. Capturing images with DirectX
Once you create the cv::VideoCapture you should give an integer not a string (since string implies the input is a file).
To open the default camera, open the stream with
cv::VideoCapture capture(0);
and it will work fine.
CMAKE GUI, MSVC++10E, Vista 32bit, OpenCV2.2
It looks like HAVE_VIDEOINPUT/WITH_VIDEOINPUT option doesn't work.
However adding: /D HAVE_DSHOW /D HAVE_VIDEOINPUT to CMAKE_CXX_FLAGS, and CMAKE_C_FLAGS did the trick for me (there will be warns due to macro redefinitions).