I am using OpenCV 2.4.10 and I want to take image from my Asus Xtion Pro Live. When I'm trying to execute the code below, I get this error: "Can not open capture."
I tried everything, like Sensor update, opencv with openni compiling and opencv re-installing (even the version 2.4.6).
OpenNI and Sensor are working properly since I am able to run examples such as NiViewer. But the example openni_capture.cpp (on opencv-2.4.10/samples/cpp) cannot run properly.
The code:
#include "opencv2/opencv.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char* argv[])
{
VideoCapture capture;
capture.open(CV_CAP_OPENNI_ASUS);
if ( !capture.isOpened() )
{
cout << "Error opening capture" << endl;
return -1;
}
if( !capture.grab() )
{
cout << "Can not grab image" << endl;
}
return 0;
}
The compiling is done with the following command:
g++ capture.cpp -o capture pkg-config --cflags opencv --libs opencv
How can i fix this error? Is there any problem with the opencv version that i use?
I did what is being said on Can not grab image from VideoCapture OpenCV with Asus Xtion Pro Live
but the problem still exists.
What serial ports are listed when you print out the list as you're doing ? Have you checked to see what serial port your camera is connected to ? On Linux you can list mounted devices with :
lsusb
Related
I am trying to learn glib and gObject for a networking project.
Here is the command used to compile (after using pkg-config to get output):
gcc socket1.c -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -lgobject-2.0 -lglib-2.0
socket1.c, after stripping, to identify the problem is:
#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <gio/gio.h>
static GSocket *mySocket;
int main(int argc, char **argv) {
GError *err1 = NULL;
mySocket = g_socket_new ( G_SOCKET_FAMILY_IPV4,
G_SOCKET_TYPE_STREAM,
G_SOCKET_PROTOCOL_TCP,
&err1);
}
The error is:
/tmp/ccKIEXOi.o: In function `main':
socket1.c:(.text+0x3d): undefined reference to `g_socket_new'
collect2: error: ld returned 1 exit status
I have tried to use readelf -Ws and nm to see if I could see g_new_socket in any of the .so files linked. I did not see any. Is there a separate library I need to link to? Where/which is it?
You need to link to libgio-2.0.so, which is the third part of GLib (GLib, GObject, GIO). You can get its compiler and linker flags from pkg-config using pkg-config --cflags --libs gio-2.0.
You can tell GSocket is in GIO by looking at the documentation — it’s in the GIO manual: https://developer.gnome.org/gio/stable/GSocket.html.
Hi Im trying to display the lena.jpg which is the first demostration for Instant OpenCV Starter Book.
I can build and play 'hello world' easy enough.
The problem code
// opencv header files
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/core.hpp"
// namespaces declaration
using namespace cv;
using namespace std;
// create a variable to store the image
Mat image;
int main( int argc, char** argv )
{
// open the image and store it in the 'image' variable
// Replace the path with where you have downloaded the image
// image=imread("<path to image">/lena.jpg");
image=imread("/home/nigel/Documents/ffmpeg/tests/lena.jpg");
// create a window to display the image
namedWindow( "Display window", CV_WINDOW_AUTOSIZE );
// display the image in the window created
imshow( "Display window", image );
// wait for a keystroke
waitKey(0);
return 0;
}
The error
g++ -Wall -fexceptions 'pkg-config --cflags opencv' -g "pkg-config --cflags
opencv' -c/home/nigel/Drone/Test2/main.cpp -o obj/Debug/Drone/Test2/main.o
g++:fatal error:no input files
compilation terminated
process terminated with status 1 (0 minutes, 0 seconds)
I have tried different paths for the lena.jpg, I changed the lena.jpg from lena.pnm not sure if I have the path right maybe ?
New to using OpenCv would appreciate some help
This error occurs when no source code file is passed in to g++. This leads me to believe there is an error in your command line arguments.
Some spots to look at:
It looks like there may be a stray quote before the second pkg-config in the line
'pkg-config --cflags opencv' -g "pkg-config --cflags opencv'
It also looks like you are missing a space between the -c and the /home/.../main.cpp
I am using OpenCV 2.4.5 on Ubuntu 12.04 64-bit. I would like to be able to set the resolution of the input from my Logitech C310 webcam. The camera supports up to 1280x960 at 30fps, and I am able to view the video at this resolution in guvcview. But OpenCV always gets the video at only 640x480.
Trying to change the resolution with cap.set(CV_CAP_PROP_FRAME_WIDTH, 1280) and cap.set(CV_CAP_PROP_FRAME_HEIGHT, 960) immediately after the VideoCapture cap is created has no effect; trying to set them immediately before getting every frame causes the program to crash immediately. I cannot reduce the resolution with this method either. I am also getting the error "HIGHGUI ERROR: V4L/V4L2: VIDIOC_S_CROP". I think this may be related, because it appears once when the VideoCapture is created, and once when I try to set the width and height (but, oddly, not if I try to set only one of them).
I know I'm not the first to have this problem, but I have yet to find a solution after much Googling and scouring of SO and elsewhere on the internet (among the many things I've already tried to no avail is the answer to this StackOverflow question: Increasing camera capture resolution in OpenCV). Is this a bug in OpenCV? If so, it's a rather glaring one.
Here's an example of code that exhibits the problem (just a modified version of OpenCV's video display code):
#include <cv.h>
#include <highgui.h>
using namespace cv;
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_FRAME_WIDTH, 160);
cap.set(CV_CAP_PROP_FRAME_HEIGHT, 120);
Mat image;
namedWindow("Video", CV_WINDOW_AUTOSIZE);
while(1)
{
// cap.set(CV_CAP_PROP_FRAME_WIDTH, 160);
// cap.set(CV_CAP_PROP_FRAME_HEIGHT, 120);
cap >> image;
imshow("Video", image);
if(waitKey(10) == 99 ) break;
}
return
}
As it is, that gets me two "HIGHGUI ERROR"s as described above and I get a 640x480 output. I know that 160x120 is a resolution that my camera supports from running v4l2-ctl --list-formats-ext. If I uncomment the two commented-out lines in the while loop, the program crashes immediately.
These might be related or have possible solutions: http://answers.opencv.org/question/11427/decreasing-capture-resolution-of-webcam/, http://answers.opencv.org/question/30062/error-setting-resolution-of-video-capture-device/
This is a bug in the v4l "version" (build) of OpenCV 2.4 (including 2.4.12), but the bug is not in the libv4l version. For OpenCV 3.1.0, neither the v4l nor the libv4l version has the bug.
(Your error error message HIGHGUI ERROR: V4L/V4L2: VIDIOC_S_CROP indicates that you have the v4l version; the message is in cap_v4l.cpp, see code, but not in cap_libv4l.cpp.)
A workaround to get the v4l version of OpenCV 2.4 to work at a fixed resolution other than 640x480 is
changing the values for DEFAULT_V4L_WIDTH and DEFAULT_V4L_HEIGHT in
modules/highgui/src/cap_v4l.cpp and re-building OpenCV, kudos to this
answer.
If you want to build the libv4l version instead, all you likely need to do is
install libv4l-dev and rebuild OpenCV; WITH_LIBV4L was enabled by default for me. If it is not, your cmake command should contain
-D WITH_LIBV4L=ON
The cmake output (or version_string.tmp) for a libv4l build contains something like
Video I/O:
...
V4L/V4L2: Using libv4l1 (ver 0.8.6) / libv4l2 (ver 0.8.6)
(For a v4l build, it is just V4L/V4L2: NO/YES.)
Just wanted to add my CMAKE options to build with Java on the Raspberry Pi 3 based on Ulrich's comprehensive answer for OpenCV 3.2.0. Make a /build folder a in the same folder as OpenCV CMakeList.txt and execute this script for the new /build folder:
sudo cmake -D CMAKE_BUILD_TYPE=RELEASE -D WITH_OPENCL=OFF -D BUILD_PERF_TESTS=OFF -D BUILD_SHARED_LIBS=OFF -D JAVA_INCLUDE_PATH=$JAVA_HOME/include -D JAVA_AWT_LIBRARY=$JAVA_HOME/jre/lib/arm/libawt.so -D JAVA_JVM_LIBRARY=$JAVA_HOME/jre/lib/arm/server/libjvm.so -D CMAKE_INSTALL_PREFIX=/usr/local -D BUILD_TESTS=OFF -D WITH_MATLAB=OFF -D WITH_CUFFT=OFF -D WITH_CUDA=OFF -D WITH_CUBLAS=OFF -D WITH_GTK=OFF -D WITH_WEBP=OFF -D BUILD_opencv_apps=OFF -D BUILD_PACKAGE=OFF -D WITH_LIBV4L=ON ..
You can use v4l2-ctl to set frame size of captured video like below.
v4l2-ctl --set-fmt-video=width=1920,height=1080,pixelformat=1
You can find more information at this link
Maybe you can try this, but I am not sure if this is what you want:
#include <X11/Xlib.h>
Display* disp = XOpenDisplay(NULL);
Screen* scrn = DefaultScreenOfDisplay(disp);
int height = scrn->height;
int width = scrn->width;
//Create window for the ip cam video
cv::namedWindow("Front", CV_WINDOW_NORMAL);
cvSetWindowProperty( "Front", CV_WND_PROP_FULLSCREEN, CV_WINDOW_FULLSCREEN );
//Position of the screen where the video is shows
cvMoveWindow("Front", 0, 0);
cvResizeWindow( "Front", width, height );
Like this you get the full screen for any screen.
I have a small OpenCV code:
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
using namespace cv;
int
main(int argc, char* argv[])
{
cv::Mat mask_img = cv::imread("image.png");
cv::imshow("window",mask_img);
return 0;
}
Yet when running I get the following error:
OpenCV Error: Assertion failed (0 <= _dims && _dims <= CV_MAX_DIM) in
setSize, file /home/box/OpenCV-2.4.3/modules/core/src/matrix.cpp, line
88 terminate called after throwing an instance of 'cv::Exception'
what(): /home/box/OpenCV-2.4.3/modules/core/src/matrix.cpp:88: error:
(-215) 0 <= _dims && _dims <= CV_MAX_DIM in function setSize
Aborted
I'm using OpenCV 2.4.3 on kubuntu linux, compiled from source.
How can I resolve this error?
I solved it myself, just use
g++ bla2.cpp `pkg-config opencv --cflags --libs` -o bla
Do not use your own linking libraries in addition like -lopencv_core etc
Is your image read properly? Try adding these lines of code after imread: if (image.empty()){ std::cerr << "Failed to read image" << std::endl; return 0;}
I have a problem with the linking simpliest test program in QTCreator:
CODE:
#include <QtCore/QCoreApplication>
#include <cv.h>
#include <highgui.h>
#include <cxcore.hpp>
using namespace cv;
int _tmain(int argc, _TCHAR* argv[])
{
cv::Mat M(7,7,CV_32FC2,Scalar(1,3));
return 0;
}
.pro file:
QT -= gui
TARGET = testopencv
CONFIG += console
CONFIG -= app_bundle
INCLUDEPATH += C:/OpenCV2_1/include/opencv
TEMPLATE = app
LIBS += C:/OpenCV2_1/lib/cxcore210d.lib \
C:/OpenCV2_1/lib/cv210d.lib \
C:/OpenCV2_1/lib/highgui210d.lib\
C:/OpenCV2_1/lib/cvaux210d.lib
SOURCES += main.cpp
I've tried to use -L and -l like LIBS += -LC:/OpenCV2_1/lib -lcxcored
And in .pro file:
QMAKE_LIBDIR += C:/OpenCV2_1/lib/Debug
LIBS += -lcxcore210d \
-lcv210d \
-lhighgui210d
The errors are like:
debug/main.o:C:\griskin\test\app\testopencv/../../../../OpenCV2_1/include/opencv/cxcore.hpp:97: undefined reference to cv::format(char const*, ...)'
Could anyone help me? Thanks!
In Visual Studio it works but I need it works in QTCreator..
Qt uses the MinGW compiler and linker. It will happily link OpenCV .libs when you use the C interface. However due to ABI issues, it will not link C++ modules.
You will have to either restrict yourself to the C interfaces only (i.e. no cv::Mat), or get OpenCV to compile with MinGw (or compile Qt in/with VS). Also, see this thread.
This is what my .pro file looks like
INCLUDEPATH += C:\\opencv\\release\\install\\include\
LIBS += -LC:\\opencv\\release\\install\\bin \
-lopencv_core240 \
-lopencv_highgui240 \
-lopencv_imgproc240 \
-lopencv_features2d240 \
-lopencv_calib3d240 \
and replace
#include <cv.h>
with
#include <opencv/cv.h>
Above .pro file works perfect for me. I have used mingw to compile OpenCV and using mingw compiler tool chain in Qt.
It seems that QtCreator cannot locate lib files.
Try specifying the include file and libs as follows.
INCLUDEPATH += C:/OpenCV2_1/build/include/
LIBS += C:/OpenCV2_1/build/gpu/x86/lib/cxcore210d.lib
you should refer to build folder if you're using pre-build version of opencv.
(I recommend pre-build version if you're not that familiar with opencv)