Successfully installed opencv 4.5.4 in windows under mingw evironment. I was able to compile opencv applications. But is there any easy way to give reference to libraries instead of typing long list of opencv libraries (i.e. something like pkg-config in windows)
For a simple opencv program I need to give reference to 4 libraries.
g++ rotate.cpp -lopencv_core454 -lopencv_highgui454 -lopencv_imgproc454 -lopencv_imgcodecs454
instead do we have some option to give list of libraries through some flags in windows environment.
Thanks
You can actually use pkg-config in Windows. If you use MSYS2 shell is is usually available or it can be installed via pacman.
Related
Having Gstreamer 1.22 successfully installed I'm not able to configure the project to build OpenCV. CMake isn't able to find GStreamer on my machine. Any ideas how two address this issue?
Just found the solution:
Cmake is using FindGstreamerWindows.cmake to find GStreamer on Windows, which is using internal an environment variable called "GSTREAMER_DIR" pointing to ..\gstreamer\1.0\x86_64.
Please make sure GSTREAMER_DIR exists on your machine.
I recently compile Opencv 4.2 with GStreamer on Windows. I use settings for GStreamer as on the following pictures. Make sure you point to correct .lib and include directories. all_Library is gstapp-1.0.lib etc, when configuraing CMAKE to compile OpenCV.
I use Opencv 4.2, CMake 3.17.0 release candidate and Gstreamer 1.16.2 MSVC 64-bit (VS 2019) developer and runtime installer. The whole process is described here install OpenCV on windows GStreamer tutorial
The important part is to set up environmental variables to find Gstreamer Runtime. Into system variable path: add
xxx\1.0\x86_64\bin
xxx\1.0\x86_64\lib
xxx\1.0\x86_64\lib\gstreamer-1.0
Gstreamer pipe from c++ opencv program to the web.
I ran clang++ -v testfile.cpp and found that many standard headers were missing from the directory C:\LLVM\lib\clang\3.9.0\include. I downloaded a pre-built binary of clang 3.9.0 for 32 bit windows from this link.
Can someone please help me sort out this mess and explain me why the standard libraries are missing in the pre-build version of clang? I've searched the web for hours to get the answer and solution to this problem but couldn't find one. Thanks in advance.
why the standard libraries are missing in the pre-build version of clang?
Your Windows binary download comprises only binary build tools
plus a handful of clang-specific headers because you are supposed
to use clang, on Windows, in lieu of another native compiler that provides your
standard library. Similarly if you install clang on Linux you'll build against
the GCC standard library by default.
Your internet search seemingly failed to lead you to Installing clang++ to compile and link on Windows, which
explains how to integrate clang with the mingw-w64 GCC standard library for 32- and/or 64-bit work
in the manner that clang for Windows expects and supports.
Does anybody know how to build cvBlobsLib using MinGW? On official page http://opencv.willowgarage.com/wiki/cvBlobsLib there is only instruction for VS.
There is also linux version of this lib http://opencv.willowgarage.com/wiki/cvBlobsLib?action=AttachFile&do=view&target=cvblobs8.3_linux.tgz , but its makefile cannot be used in windows as i see.
If you use eclipse then you dont have a lot of work:
Create a new project, using MinGW toolchain.
Go to the project properties, and under C/C++ General >> Paths and Symbols add the openCV library paths.
compile the project and it should be OK.
Use this
http://opencv.willowgarage.com/wiki/cvBlobsLib#Build_intructions
if you have more problems (especially NOTE 3)
Z3's dependency on libgmp.so.3 is unresolved in the linux package, leaving the user to provide this library. However, this library is very old and is not readily available.
Does anyone know a method for getting around this issue? I am currently running x86_64 and cannot get around this missing dependency without a great deal of hassle.
Is it possible the linux packages could be fixed such they include the expected library in the distribution?
You can get GMP3 by executing sudo apt install libgmp3-dev.
I'm not a Linux expert, but this is the command I used to install GMP before I compiled Z3.
When I installed the virtual machine for running Linux 64, I think I didn't find a package for the more recent versions of GMP.
I will try again. If it doesn't work, I will download the most recent GMP tar ball and build it from scratch.
BTW, the Z3 for Linux 32 comes with two .so files. One of them has GMP statically linked.
The trick I used for building this .so file didn't work for the 64 bit version.
As I said, I'm not a Linux expert, any suggestions on how to build a better Z3 library for Linux x86_64 users are welcome.
The Accelerate framework is a Mac-specific framework that provides things like image convolutions and LAPACK, supposedly optimized to be as fast as possible on Macs. My question: Does OpenCV take advantage of this? Specifically, does the function "filter2D" use Accelerate?
It does not use the Accelerate framework, but it looks like it has been speeded up using the CUDA stuff in 2.2
The relevant files in OpenCV2.2 ...
/modules/gpu/include/opencv2/gpu/gpu.hpp
/modules/gpu/src/filtering.cpp
and
modules/imgproc/src/filter.cpp
for the non-gpu stuff
Not a mac expert but AFAIK openCV uses IPP (if installed) TBB (build option) and NVidia-CUDA (build option)
If you use the MacPorts version, you can specify the options
$ port variants opencv
opencv has the variants:
debug: Enable debug binaries
python26: Add Python 2.6 bindings
* conflicts with python27
python27: Add Python 2.7 bindings
* conflicts with python26
tbb: Use Intel TBB
universal: Build for multiple architectures
I have used
sudo port install py26-numpy
sudo port install opencv +python26 +tbb
with success. Concerning the Accelerate.framework specifically, this blog entry says "# Add Accelerate.framework which is used internally from OpenCV library.", but I have no clue as to know if it is the case here.