如何将 Imagemagick 库链接到 Qt(windows)

Question

I have developed an application with mac and for one month now, Im trying to link Qt with ImageMagick on windows.

I just cant find the files and the version of Imagemagick library that need to be linked to Qt in order to make my application work on windows.

I have tried most of the libraries from here

Thats the only thing I added to the .pro file while I was developing on a mac

INCLUDEPATH += . /opt/local/include/ImageMagick
LIBS += -L/opt/local/lib -lMagick++

When I add this to my .pro

INCLUDEPATH += C:/im6/include/ImageMagick
LIBS += C:/im6/lib/libMagickWand.a
LIBS += C:/im6/lib/libMagick++.a
LIBS += C:/im6/lib/libMagickCore.a
C:/im6/lib/libMagick++.a

I get 10.000 + simmilar errors to that:

(Image.o):C:\msys\1.0\home\cristy\ImageMagick-6.6.6-0/Magick++/lib/Image.cpp:4157: undefined reference to `__gxx_personality_sj0'
    
    C:/im6/lib/libMagick++.a(Image.o):C:\msys\1.0\home\cristy\ImageMagick-6.6.6-0/Magick++/lib/Image.cpp:4157: undefined reference to `_Unwind_SjLj_Register'
    
    C:/im6/lib/libMagick++.a(Image.o):C:\msys\1.0\home\cristy\ImageMagick-6.6.6-0/Magick++/lib/Image.cpp:4178: undefined reference to `_Unwind_SjLj_Unregister'

For more errors check this

Has anyone tried to build and deploy an ImageMagick application using qt on windows ? Which files do I need to link while building and which files while deploying ?

Answer 1

1. The error message tells me that you use mingw (with qtcreator). Your library might not work with this compiler. You need a mingw version of the library, probably named libmagick.a.

2. LIBS += -L$$quote(c:/Program Files/ImageMagick-6.6.5-Q16/lib) -lmagick (see the documentation about qmake Project Files

Answer 2

Please go get ImageMagick source package.

I can't give direct instructions how to work with MinGW of Qt Creator, but basically following. I prefer to use qtvars.bat that comes with binary distributions of Qt to set environment.

1. Open Windows cmd
2. Set PATH to have /path/to/mingw/bin and /path/to/qt/bin before other paths
3. Go to directory where you have extracted ImageMagick source
4. read README, INSTALL and such to compile the ImageMagick (most likely just ./configure ; mingw32-make, but never be sure)
5. Edit your .pro file with something like LIBS += -L$$quote(/path/to/imagemagick/lib/dir) -lmagick . The lib may be in bin dir or in lib dir. See hmuelner's answer for more information.

At this point, the configuration should be ready. Compilation at Qt Creator should work, but you can as well use this cmd windows to compile your program: go to program directory, run “qmake” and “mingw32-make”.

Answer 3

You cannot link against a ImageMagick++ library built with MSVC, as mingw and MSVC DLLs are incompatible for C++ libraries. You can't link a MSVC-built C++ library into a mingw project, nor vice versa. C-only libraries work fine. Also, according to this fortum thread , using builds against old mingw-versions with current mingw versions doesn't work as the exception handling changed (as you get more errors than that, I wouldn't expect that to be the only problem though). If there is no binary package for your mingw version (and I don't see any on the imagemagick website), your only option is to use a source package, as Smar suggests.

Another option of course is to install Visual Studio, download Qt for MSVC and build your project with MSVC.

Answer 4

I have found that the minGW tool set is very much treated as a "stepchild" in the Windows world. I know it doesn't help your particular situation, but we had numerous problems with third-party libs while trying to use Qt with minGW. There were always extra steps, or non-existent build instructions that we had to figure out or tweak.

Once we switched to the MSVC version, all of those problems went away. Note that this doesn't mean you have to use Visual Studio (you can still use Qt creator), it just means that the Visual Studio compiler is being used. You can get the compiler for free using the Platform SDK. If this is an option, you might save yourself a lot of pain by switching now. It's unfortunate, but that is just the current status quo, at least as we discovered.