Runtime errors when coding OpenCV programs using codeBlocks in linux - c++

When I try to compile a C++ program which uses the openCV library in CodeBlocks it gives me a runtime error :
error while loading shared libraries: libopencv_calib3d.so.2.2:
cannot open shared object file: no such file or directory
This is in spite of the fact that I have added all the required libraries using linker settings for the Code Blocks IDE (including the one named libopencv_calib3d.so.2.2 which is a symbolic link).
However I'm able to compile the program using the command line by issuing the command :
g++ hello-world.cpp -o hello-world \
-I /usr/local/include/opencv -L /usr/local/lib
\ -lm -lcv -lhighgui -lcvaux
Can somebody advise me on how I can get to run the same using Code Blocks.
Thanks!

The file libopencv_calib3d.so.2.2 is part of OpenCV 2.2. There is, however, no libcv, libhighgui or libcvaux part of OpenCV 2.2. This means that your g++ call links against another version of OpenCV.
To link against OpenCV 2.2, you would need flags like -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann.
You should also not put them in manually, but instead use
export PKG_CONFIG_PATH=/usr/local/share/opencv/:$PKG_CONFIG_PATH
g++ `pkg-config --cflags --libs opencv` hello-world.cpp -o hello-world

I would recommend installing a reasonably up-to-date version of OpenCV for Linux, 2.4.9 for example, at this time of writing, appears to build with the current version of gcc that I have (4.8.2). There are a few steps you need to complete in order to get a simple OpenCV example up and running in Code::Blocks. The OpenCV documentation tells you to create a build directory within your OpenCV root directory and run cmake, make, sudo make install etc in order to generate the libraries your project may need to link to, including the libopencv_calib3d.so you mention:
This blog posting gives explanations on how to install OpenCV and configure it's use for Code::Blocks in Ubuntu Linux environments:
http://www.technical-recipes.com/2014/using-opencv-in-codeblocks-in-linux/

Related

Error loading SDL2 shared libraries while executing program on another pc

I'm trying to compile a program i made using SDL2 to work on others computers (or testing VM in this case).
I've been compiling it with what i think are the correct flags, e.g. g++ main.cpp -o main -lSDL2, however when i try executing it on another Ubuntu installation i get this error.
error while loading shared libraries: libSDL2-2.0.so.0: cannot open shared object file: No such file or directory
From my understanding it's not a problem in my compiling but with how i expect it to work on another Linux installation; I've cross-compiled (using mingw32) and tested it (using a freshly installed VM) on Windows adding the correct dlls with the exe (seems to work fine) and I was expecting for it to work in a similar fashion.
What's the standard in this cases? Should i write a setup scripts to install the library dependencies on the target machine? Is there another way I'm not aware of? I've never released an application for Linux (nor Windows) and I'm struggling to find the resources to do things "the right way".
Thanks for everyone suggestions, I ended up settling for the easy way, compiling the "easy to install" libraries dynamically e.g.-lSDL2 and the others statically (checked the licenses and it should be fine) like so:
g++ main.cpp -o main -Wl,-Bdynamic -lSDL2 -lSDL2_image -lSDL2_ttf -Wl,-Bstatic -lSDL2_gfx -static-libgcc -static-libstdc++
I'll put in my documentation how to install the required SDL2 libraries.
I am not sure how familiar you are with pkg-config, but the output for sdl2 is this:
-D_REENTRANT -I/usr/include/SDL2 -lSDL2
This was found from running this:
pkg-config --cflags --libs sdl2
Basically, you need to point to where SDL2 is located BEFORE you actually link to it.
The tool pkg-config is designed to tell you the information you need when you want to link to a package in Linux. You were linking with the library, but you forgot to tell GCC where the library is located.
If you want to compile you code, try this:
g++ main.cpp -o runme `pkg-config --cflags --libs sdl2`
This will automatically grab all of the flags that you need to compile with SDL2 included.
Oh, and you should note, ORDER MATTERS WHEN ADDING FLAGS AND LIBRARIES!!!
There are many questions on SO where the order of compiler options caused all of the problems. Do not be like those people. I suggest you search SO for more info on that.

Building GDAL with all libraries static

I want to develop a small program that checks which polygons from a shapefile intersect a given rectangle. This program is to be used in a website (with PHP's exec() command). The problem is, my webserver cannot install GDAL, for reasons unknown to me. So I can't link to the shared libraries. Instead, I must link to static libraries, but these aren't given.
I've downloaded the GDAL source code from here (2.3.2 Latest Stable Release - September 2018), and followed the build instructions from here. Since I already have GDAL working on my Debian, and don't want to mess with it, I followed the "Install in non-root directory" instructions, with some adjusts from the last item in the "Some caveats" section:
cd /home/rodrigo/Downloads/gdal232/gdal-2.3.2
mkdir build
./configure --prefix=/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/ --without-ld-shared --disable-shared --enable-static
make
make install
export PATH=/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/bin:$PATH
export LD_LIBRARY_PATH=/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/lib:$LD_LIBRARY_PATH
export GDAL_DATA=/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/share/gdal
/usr/bin/gdalinfo --version
build/bin/gdalinfo --version
The first /usr/bin/gdalinfo --version gives 2.1.2 (the previous installed version). The second, build/bin/gdalinfo --version, gives 2.3.2 (the version just built).
By now, my program only uses the ogrsf_frmts.h header, which is in /usr/include/gdal/ or /home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/include/ directory, depending on the build. There's no ogrsf_frmts.a file, but only a libgdal.a. Is this the file I should be linking against? If so, how? I've tried so far:
gcc geofragc.cpp -l:libgdal.a
gcc geofragc.cpp -Wl,-Bstatic -l:libgdal.a
gcc geofragc.cpp -Wl,-Bstatic -l:/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/lib/libgdal.a
gcc geofragc.cpp -Wl,-Bstatic -l/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/lib/libgdal.a
gcc geofragc.cpp /home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/lib/libgdal.a
gcc geofragc.cpp -l/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/lib/libgdal.a
gcc geofragc.cpp -l:/home/rodrigo/Downloads/gdal232/gdal-2.3.2/build/lib/libgdal.a
but nothing works. What am I missing?
EDIT
The second trial (gcc geofragc.cpp -Wl,-Bstatic -l:libgdal.a) is giving the following error:
/usr/bin/ld: cannot find -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/6/../../../../lib/libgdal.a(gdalclientserver.o): In function `GDALServerSpawnAsync()':
(.text+0x1f5e): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: cannot find -lgcc_s
collect2: error: ld returned 1 exit status
You can use the gdal-config program to get correct options for compilation and linking. This program is a part of the GDAL library and it has its own options:
hekto#ubuntu:~$ gdal-config --help
Usage: gdal-config [OPTIONS]
Options:
[--prefix[=DIR]]
[--libs]
[--dep-libs]
[--cflags]
[--datadir]
[--version]
[--ogr-enabled]
[--gnm-enabled]
[--formats]
You have to make sure this program is on your search path, or you can create an alias - for example:
alias gdal-config='/home/rodrigo/Downloads/gdal232/gdal-2.3.2/bin/gdal-config'
Now your compilation and linking command becomes the following one:
g++ `gdal-config --cflags` geofragc.cpp `gdal-config --libs` `gdal-config --dep-libs`
You have to use the g++ compiler to link with C++-built libraries.
Another option is to create a Makefile with these lines:
CXXFLAGS += ${shell gdal-config --cflags}
LDLIBS += ${shell gdal-config --libs}
LDLIBS += ${shell gdal-config --dep-libs}
geofragc: geofragc.cpp
and just call make with this Makefile.
I hope, it'll help.

Qt5.5 static build cannot find -IGL on ubuntu14

I have compiled qt 5.5 for static building and it works fine.
However, when I add the widgets "QT += widgets" in the pro file I get the link error "cannot find -IGL"
From what I read this is to do with the Open GL libs. I have tried the following:
sudo apt-get install libglu1-mesa-dev
and
sudo apt-get install libgl1-mesa-dev
But no luck here... I am wondering if I need a static version of this? or maybe a symlink is missing, but I can't figure out the next step :(
Edit This is the actual error message:
g++ -static -static-libgcc -static-libstdc++ -Wl,-O1 -o ../targetRel/McpSupervisor main.o cconfig.o cconfigxml.o mcpprocessbase.o rpeprocess.o supervisor.o cipcomms.o mcpsupervisor_plugin_import.o moc_mcpprocessbase.o moc_supervisor.o moc_cipcomms.o -L/usr/lib/i386-linux-gnu/mesa -L/usr/local/Qt-5.5.1/lib -lQt5Xml -lQt5Widgets -L/usr/local/Qt-5.5.1/plugins/bearer -lqconnmanbearer -lqgenericbearer -lqnmbearer -lQt5Network -L/usr/local/Qt-5.5.1/plugins/platforms -lqxcb -L/usr/local/Qt-5.5.1/plugins/xcbglintegrations -lqxcb-glx-integration -lxcb-glx -lQt5XcbQpa -lX11-xcb -lXi -lxcb-render-util -lxcb-render -lxcb -lxcb-image -lxcb-icccm -lxcb-sync -lxcb-xfixes -lxcb-shm -lxcb-randr -lxcb-shape -lxcb-keysyms -lxcb-xkb -lQt5PlatformSupport -lfontconfig -lfreetype -lQt5DBus -lXrender -lXext -lX11 -L/usr/local/Qt-5.5.1/plugins/imageformats -lqdds -lqicns -lqico -lqjp2 -lqmng -lqtga -lqtiff -lqwbmp -lqwebp -lQt5Gui -lpng -lqtharfbuzzng -lQt5Core -lz -licui18n -licuuc -licudata -lqtpcre -lm -ldl -pthread -lgthread-2.0 -lglib-2.0 -lrt -lGL -lpthread
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libX11.a(CrGlCur.o): In function open_library':
(.text+0x33): warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: cannot find -lGL
/usr/local/Qt-5.5.1/plugins/imageformats/libqjp2.a(jas_stream.o): In functionjas_stream_tmpfile':
jas_stream.c:(.text+0x7a4): warning: the use of tmpnam' is dangerous, better usemkstemp'
/usr/local/Qt-5.5.1/lib/libQt5Core.a(qfilesystemengine_unix.o): In function QFileSystemEngine::resolveGroupName(unsigned int)':
qfilesystemengine_unix.cpp:(.text+0x943): warning: Using 'getgrgid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libglib-2.0.a(libglib_2_0_la-gutils.o): In functiong_get_user_database_entry':
(.text+0x25a): warning: Using 'getpwuid' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/libglib-2.0.a(libglib_2_0_la-gutils.o): In function g_get_user_database_entry':
(.text+0xa3): warning: Using 'getpwnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/local/Qt-5.5.1/lib/libQt5Core.a(qfilesystemengine_unix.o): In functionQFileSystemEngine::resolveUserName(unsigned int)':
qfilesystemengine_unix.cpp:(.text+0x592): warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/local/Qt-5.5.1/lib/libQt5Network.a(qhostinfo_unix.o): In function `QHostInfoAgent::fromName(QString const&)':
qhostinfo_unix.cpp:(.text+0x580): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
collect2: error: ld returned 1 exit status
make: *** [../targetRel/McpSupervisor] Error 1
09:49:17: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project qtMain (kit: Qt 5.5.1 GCC 32bit Static)
When executing step "Make"
09:49:17: Elapsed time: 00:08.
What is your actual problem :
You have unmet dependencies .
You are thinking that you have all the required dependencies because you installed
sudo apt-get install libglu1-mesa-dev
sudo apt-get install libgl1-mesa-dev
The problem is that you have a i386 system that is x32 system.
But you have installed development files for x64 systems using the commands above
Here is the ANSWER :
Intsall the following things
sudo apt-get install libgl1-mesa-dev:i386
sudo apt-get install libglu1-mesa-dev:i386
Now it should work ;)
Some other helpful stuff for visitors to this particular question
The lines below were my attempt to solve the problem but they did not work because the person who asked the question has a x32 system but the comments below work for x64 systems . But never the less the meta answer below will serve well for people who have the same problem and x64 systems. And also it will help problem to understand what are the basic steps to do after a similar problem occurs
# code_fodder I wanted to ask a question by making a comment below your question but I do not have 50 reputations to do so.
So I have to use the answer submission form to do so. :(
Do you have Miscellaneous Mesa GL utilities ?
If you dont have them then install using
sudo apt-get install mesa-utils
If you want to use OpenGl ES then you have to install Miscellaneous Mesa utilies (opengles, egl) using
sudo apt-get install mesa-utils-extra
Let me know if that works .
POSTING NEW INFORMATION ON 17-DEC-2015
I will post a portion of my project.pro file here . It specifically contains the library linking methods that I used for a simple OpenGL project.
I am using GLEW with OpenGL and SDL2
TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle
CONFIG -= qt
SOURCES += main.cpp \
mesh.cpp \
display.cpp \
shader.cpp
HEADERS += \
mesh.h \
display.h\
shader.h
unix|win32: LIBS += -lGL \
-lGLEW \
/usr/local/lib/libSDL2-2.0.so
As you can notice I am using both static and dynamically linked libraries.
You may need to add:
unix | win32: LIBS += -L/usr/lib/x86_64-linux-gnu/mesa/ to your .pro file. However the path may be different for 32 bit systems. In that folder there are is the required mesa library files. These are the files for my system.
zehel#zehel-PC:/usr/lib/x86_64-linux-gnu/mesa$ ls
ld.so.conf libGL.so libGL.so.1 libGL.so.1.2.0
Try compiling now and see if that works
If that doesn't then either you have unmet dependencies or you are using old OpenGL.
Now after running the sudo apt-get install mesa-utils you will be able to use a command called glxinfo . It will show you all required information about your graphics card.
Run glxinfo | grep "OpenGl version string"
It will show you what version of OpenGl and mesa you have
mine is like this
OpenGL version string: 3.0 Mesa 10.3.2
If they are less than 3.0 then you are not using modern OpenGL and you may want to update your graphics drivers.
But if they are 3.0 or above then you are probably okay.
I cant reproduce your problem so I think that you have missing dependencies
See this posts on the QT forum where people with same problem as you are saying that there problems were fixed after installing the dependencies
http://forum.qt.io/topic/36282/solved-qt-5-2-0-and-lgl-issue
The last answer in the qt forum is quite good please refer it.
Update me whether it works or not .
Hope That helps .
You might need to specify the path where the GL library can be found, for exmaple by using the -L option to GCC, which has the following man page description:
-Ldir
Add directory dir to the list of directories to be searched for -l.

Opencv + Boost: Undefined references

I have a computer vision source code that is related to find copy and move portions in a forged image. I cannot compile this source code that uses openCV and Boost, some of the errors include undefined references to OpenCv stuff, for example:.
main.cpp:(.text+0x3cc1): undefined reference to `cvSetZero'
My makefile is the following. I think I correctly indicate the boost and opencv libraries. What could be wrong?
# Boost library is required
BOOST_LIBS=-L/usr/include/boost -lboost_system -lboost_random
BOOST_INCLUDE=-I/usr/include/boost
BOOST_VERSION=103500
OPENCV_INCLUDE=-I/usr/include/opencv2/
OPENCV_LIBS=-L/usr/include/opencv2/ -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_flann -lopencv_calib3d
OPENCV_LIBS=-L/usr/lib/opencv2/ -lopencv_core ...
^^^
You might want to check if OpenCV is installed correctly and where this installation is located. Afterwards you can adjust your makefile. How to do this depends on your OS.
E.g. on Linux you might want to search for the opencv_core.so (e.g. via locate -b opencv_core).
In my case it would be
OPENCV_LIBS=-L/usr/lib/ -lopencv_core
if you have pkg-config installed, and if it knows where OpenCV is, you can try
OPENCV_INCLUDE=$$(pkg-config --cflags opencv)
OPENCV_LIBS=$$(pkg-config --libs opencv)

Problem with cmake and OpenCV 2.0 in Ubuntu

Goodnight, I'm working in a project where we use Cmake and OpenCV 2.0 in Ubuntu 10.04, everyone in the team(we are a micro-mouse contest team) can compile code just fine, but I cant.
This is what Cmake says to me:
tiago#tiago-laptop:~/bioloid/build$ cmake ..
-- Checking GNUCXX version 3/4 to determine OpenCV /opt/net/ path
CMake Error at CMakeModules/FindOpenCV.cmake:348 (MESSAGE):
OpenCV required but some headers or libs not found. Please specify it's
location with OpenCV_ROOT_DIR env. variable.
Call Stack (most recent call first):
CMakeLists.txt:45 (FIND_PACKAGE)
-- Configuring incomplete, errors occurred!
If I try to export the variable like this:
export OpenCV_ROOT_DIR=/usr/local/lib
It keeps giving the same error, this is the output from pkg-config --cflags --libs opencv:
-I/usr/local/include/opencv -I/usr/local/include -L/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann
No one in the team knows what do do, I have already removed and re-instaled opencv, is there any chance that this is because I also have opencv 2.2 instaled in my computer?
As you are using a custom Find macro to find opencv (CMakeModules/FindOpenCV.cmake) you should actually check which libraries this macro requires to find. As it looks like this macro is actually under your control, I would just add debug messages to its processing to find out at which point it fails. If the macro uses a call to MARK_AS_ADVANCED a good strategy could be print out all variables that are passed into this macro. All variables need to have a value that is not empty, false or XXX-NOTFOUND.
Apart from that, making the code of this find macro available to us would help in debugging.