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2021-03-26 07:07:02 -0500 received badge  Notable Question (source)
2020-07-07 04:36:09 -0500 received badge  Popular Question (source)
2019-10-28 04:27:41 -0500 received badge  Popular Question (source)
2019-09-04 15:55:46 -0500 received badge  Popular Question (source)
2019-08-27 00:37:15 -0500 received badge  Popular Question (source)
2019-02-26 04:44:56 -0500 asked a question How to use OpenCL cache

How to use OpenCL cache clBuildProgram() can be slow, but its results are cached (by OpenCV and by some OpenCL implement

2019-01-23 10:56:37 -0500 edited question How to detect workgroup size used?

How to detect wourkgroup sized used? Hello, I am trying to understand more DNN module with OpenCL backend. It seems by

2019-01-23 10:00:40 -0500 asked a question How to detect workgroup size used?

How to detect wourkgroup sized used? Hello, I am trying to understand more DNN module with OpenCL backend. It seems by

2019-01-23 09:57:37 -0500 edited question OPENCV_OCL4DNN_DISABLE_AUTO_TUNING

OPENCV_OCL4DNN_DISABLE_AUTO_TUNING Hello, I would like to use OPENCV_OCL4DNN_DISABLE_AUTO_TUNING option to tune opencl

2019-01-23 09:57:07 -0500 asked a question OPENCV_OCL4DNN_DISABLE_AUTO_TUNING

OPENCV_OCL4DNN_DISABLE_AUTO_TUNING Hello, I would like to use OPENCV_OCL4DNN_DISABLE_AUTO_TUNING option to tune opencl

2018-12-18 07:04:28 -0500 commented question OpenCV dnn import quantized model

Can dnn module leverage on that (some speed-up) if used quantized model?

2018-12-18 01:37:29 -0500 commented question OpenCV dnn import quantized model

So what's benifit of that though?

2018-12-18 01:34:58 -0500 edited question OpenCV dnn import quantized model

OpenCV dnn import quantized model Is it possible to load NN quantized model of tensorflow? The nodes and weights of a n

2018-12-17 09:01:56 -0500 asked a question OpenCV dnn import quantized model

OpenCV dnn import quantized model Is it possible to load NN quantized model of tensorflow? Ifso how? Thank you.

2018-12-11 05:35:26 -0500 edited question How to set WORK GROUP SIZE?

CL_INVALID_WORK_GROUP_SIZE I have short test program trying to use OpenCL version of functions ... cv::ocl::setUseOpenC

2018-12-11 05:34:29 -0500 edited question How to set WORK GROUP SIZE?

CL_INVALID_WORK_GROUP_SIZE I have short test program trying to use OpenCL version of functions ... cv::ocl::setUseOpenC

2018-12-11 03:46:22 -0500 edited question How to set WORK GROUP SIZE?

CL_INVALID_WORK_GROUP_SIZE I have short test program trying to use OpenCL version of functions ... cv::ocl::setUseOpenC

2018-12-11 03:31:14 -0500 asked a question How to set WORK GROUP SIZE?

CL_INVALID_WORK_GROUP_SIZE I have short test program trying to use OpenCL version of functions ... cv::ocl::setUseOpenC

2018-12-11 03:28:56 -0500 asked a question How to set WORK GROUP SIZE?

CL_INVALID_WORK_GROUP_SIZE I have short test program trying to use OpenCL version of functions ... cv::ocl::setUseOpenC

2018-12-10 15:18:26 -0500 edited question How to convert Mat <-> UMat back-and-forth

How to convert Mat <-> UMat back-and-forth I'd like to know how to convert UMat image onto Mat and back-and-forth.

2018-12-10 12:30:23 -0500 edited question How to convert Mat <-> UMat back-and-forth

How to convert Mat <-> UMat back-and-forth I'd like to know how to convert UMat image onto Mat and back-and-forth.

2018-12-10 12:29:33 -0500 edited question How to convert Mat <-> UMat back-and-forth

How to convert Mat <-> UMat back-and-forth I'd like to know how to convert UMat image onto Mat and back-and-forth.

2018-12-10 12:28:35 -0500 asked a question How to convert Mat <-> UMat back-and-forth

How to convert Mat <-> UMat back-and-forth I'd like to know how to convert UMat image onto Mat and back-and-forth.

2018-12-05 13:48:27 -0500 commented question OpenCV Development Enviroment

how about Eclipse?

2018-12-05 04:46:58 -0500 asked a question OpenCV Development Enviroment

OpenCV Development Enviroment I am looking for an advice how to effectivelly develop within OpenCV. How to setup develop

2018-11-09 03:04:11 -0500 asked a question DNN Importer

DNN Importer Are there any plans or actual use of Machinelareaning framerworks importer such as ONNX or NNEF?

2018-08-13 05:35:08 -0500 received badge  Notable Question (source)
2017-09-10 03:26:12 -0500 commented question Hog compilation error

Access HOG from within OpenVX framework

2017-09-09 18:34:41 -0500 commented answer How to visualize the 32 dimension HOG from DPM?

in my case I have HOGDescriptor d1(Size(512, 512), Size(16, 16), Size(16, 16), Size(16, 16), 9); by calling Mat r1 = g

2017-09-09 17:04:43 -0500 commented question Hog compilation error

have you got any cv knowledge yourself?

2017-09-09 13:29:16 -0500 asked a question Hog compilation error

Hog compilation error Dears, I'm trying to understand HOG descriptor which I am using e.g. //extraction of HoG feature

2017-09-05 04:32:00 -0500 commented answer Histogram of Oriented Gradients

Hi Steven, can I advice where to extract from?

2017-09-05 01:53:54 -0500 asked a question Histogram of Oriented Gradients

Histogram of Oriented Gradients Hello, I'm looking for an example of Histogram of Oriented Gradients, is it implented w

2017-05-18 14:23:31 -0500 received badge  Popular Question (source)
2016-10-05 11:40:32 -0500 asked a question Chapter4_StructureFromMotion

Hello,

I'm trying to use Chapter4_StructureFromMotion example from https://github.com/MasteringOpenCV/code abd its book. I use now opencv 3.1.0 andby compiling that I got

/Chapter4_StructureFromMotion/GPUSURFFeatureMatcher.h:10:31: fatal error: opencv2/gpu/gpu.hpp: No such file or directory

How to port it to newer version of opencv, particularly for gpu? Thanks.

Regards, Peter

2016-08-27 01:59:33 -0500 asked a question blockmatching.h:0: Note: No relevant classes found.

Dears,

I'm trying to use OpenCVBM application from https://github.com/DLuensch/StereoVis... that use OpenCV but by compiling I am getting:

pb@pb:~/work/StereoVision-ADCensus-master/OpenCVBM/build$ make
[  6%] Generating ui_blockmatchingimage.h
[ 13%] Generating src/moc_OpenCVBMWindow.cxx
[ 20%] Generating src/moc_blockmatchingimage.cxx
[ 26%] Generating src/moc_blockmatching.cxx
/home/r59400/work/StereoVision-ADCensus-master/OpenCVBM/src/blockmatching.h:0: Note: No relevant classes found. No output generated.
[ 33%] Generating src/moc_sgblockmatching.cxx
/home/work/StereoVision-ADCensus-master/OpenCVBM/src/sgblockmatching.h:0: Note: No relevant classes found. No output generated.
[ 40%] Generating ui_OpenCVBMWindow.h
Scanning dependencies of target OpenCVBM
[ 46%] Building CXX object CMakeFiles/OpenCVBM.dir/src/main.cpp.o
[ 53%] Building CXX object CMakeFiles/OpenCVBM.dir/src/OpenCVBMWindow.cpp.o
[ 60%] Building CXX object CMakeFiles/OpenCVBM.dir/src/blockmatchingimage.cpp.o
[ 66%] Building CXX object CMakeFiles/OpenCVBM.dir/src/blockmatching.cpp.o
/home/r59400/work/StereoVision-ADCensus-master/OpenCVBM/src/blockmatching.cpp: In member function ‘cv::Mat BlockMatching::updateBM()’:
/home/r59400/work/StereoVision-ADCensus-master/OpenCVBM/src/blockmatching.cpp:165:13: error: base operand of ‘->’ has non-pointer type ‘cv::StereoBM’
     this->bm->compute(this->imageLeft, this->imageRight, res);
             ^
make[2]: *** [CMakeFiles/OpenCVBM.dir/src/blockmatching.cpp.o] Error 1
make[1]: *** [CMakeFiles/OpenCVBM.dir/all] Error 2
make: *** [all] Error 2

Do you have any advice what's root-cause of this? I would appreciate your help.

Thank you.

2016-02-16 14:23:44 -0500 received badge  Student (source)
2016-02-05 15:29:32 -0500 commented answer Build OpenCV for Python

Since I am building python2 why should I need to have python3.4? Does it mean that opencv 3.1 does not support python2?

2016-01-24 06:22:48 -0500 asked a question Build OpenCV for Python

Dears,

I'm trying to build OpenCV including with CMAKE option "BUILD_opencv_python2" - I finshed always with errors:

CMAKE configurtion says:

Detected version of GNU GCC: 53 (503)
CUDA compilation is disabled (due to only Visual Studio compiler supported on your platform).
Could NOT find PythonInterp: Found unsuitable version "2.7.10", but required is at least "3.4" (found C:/Python27/python.exe)
Could NOT find PythonInterp: Found unsuitable version "2.7.10", but required is at least "3.2" (found C:/Python27/python.exe)

General configuration for OpenCV 3.1.0-dev =====================================
  Version control:               1cd3c6f

  Platform:
    Host:                        Windows 6.1.7601 AMD64
    CMake:                       3.4.2
    CMake generator:             MinGW Makefiles
    CMake build tool:            C:/mingw-w64/i686-5.3.0-posix-dwarf-rt_v4-rev0/mingw32/bin/mingw32-make.exe
    Configuration:               Release
  C/C++:
    Built as dynamic libs?:      YES
    C++ Compiler:                C:/mingw-w64/i686-5.3.0-posix-dwarf-rt_v4-rev0/mingw32/bin/g++.exe  (ver 5.3.0)
    C++ flags (Release):         -fsigned-char -mstackrealign -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -march=i686 -fomit-frame-pointer -msse -msse2 -mfpmath=sse -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -O2 -DNDEBUG  -DNDEBUG
    C++ flags (Debug):           -fsigned-char -mstackrealign -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -march=i686 -fomit-frame-pointer -msse -msse2 -mfpmath=sse -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -g  -O0 -DDEBUG -D_DEBUG
    C Compiler:                  C:/mingw-w64/i686-5.3.0-posix-dwarf-rt_v4-rev0/mingw32/bin/gcc.exe
    C flags (Release):           -fsigned-char -mstackrealign -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -fdiagnostics-show-option -march=i686 -fomit-frame-pointer -msse -msse2 -mfpmath=sse -ffunction-sections -fvisibility=hidden -O2 -DNDEBUG  -DNDEBUG
    C flags (Debug):             -fsigned-char -mstackrealign -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -fdiagnostics-show-option -march=i686 -fomit-frame-pointer -msse -msse2 -mfpmath=sse -ffunction-sections -fvisibility=hidden -g  -O0 -DDEBUG -D_DEBUG
    Linker flags (Release):      
    Linker flags (Debug):        
    Precompiled headers:         YES
    Extra dependencies:          comctl32 gdi32 ole32 setupapi ws2_32 vfw32 winmm
    3rdparty dependencies:       zlib libjpeg libwebp libpng libtiff libjasper IlmImf

  OpenCV modules:
    To be built:                 core flann imgproc ml photo video imgcodecs shape videoio highgui objdetect superres ts features2d calib3d stitching videostab python2
    Disabled:                    world
    Disabled by dependency:      -
    Unavailable:                 cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev java python3 viz

  Python 2:
    Interpreter:                 C:/Python27/python.exe (ver 2.7.10)
    Libraries:                   C:/Python27/libs/libpython27.a (ver 2.7.10+)
    numpy:                       C:/Python27/Lib/site-packages/numpy/core/include (ver 1.9.2)
    packages path:               C:/Python27/Lib/site-packages

  Python (for build):            C:/Python27/python.exe

I have installed python, numpy - it's working.

First question: Do not understand why CMAKE says: Found unsuitable version "2.7.10", but required is at least "3.4" ?

Secondly - when "make" runs to build it ends up with:

[ 98%] Linking CXX shared module ..\..\lib\cv2.pyd
C:/Python27/libs/libpython27.a: error adding symbols: File format not recognized
collect2.exe: error ...
(more)
2016-01-24 03:52:44 -0500 commented answer Python & Video - freeze

Thanks for your help! I got it - my fault :( I just copied "python examples" from https://opencv-python-tutroals.readth... - I should better check - Thank very much helping me out!

2016-01-24 03:48:10 -0500 commented question Python & OpenCV

Thanks a lot! I got it. Then I check it with "whos" command in python console and img is really empty - so that's why not working - I fix it - now works. I moved img source same directory as python script. Anyway need to check first img if not empty or cv2.imshow should probably return "img empty" instead of "error" - just little comments. Thanks for your help!

2016-01-23 10:18:08 -0500 asked a question Python & Video - freeze

Dears,

I got running exampe

import numpy as np
import cv2

cap = cv2.VideoCapture('vtest.avi')

while(cap.isOpened()):
    ret, frame = cap.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame',gray)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()

When video finishes I got error at Python console and freeze

Traceback (most recent call last):

  File "<ipython-input-1-2cc765029316>", line 1, in <module>
    runfile('C:/tmp/untitled1.py', wdir='C:/tmp')

  File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 685, in runfile
    execfile(filename, namespace)

  File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 71, in execfile
    exec(compile(scripttext, filename, 'exec'), glob, loc)

  File "C:/tmp/untitled1.py", line 16, in <module>
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

error: ..\..\..\modules\imgproc\src\color.cpp:3739: error: (-215) scn == 3 || scn == 4 in function cv::cvtColor

What correctly to stop video?

Best regards, Peter

2016-01-23 09:11:19 -0500 asked a question Python & OpenCV

Dears,

I try to use OpenCV in Python, and running example such as

import numpy as np
import cv2

img = cv2.imread('messi5.jpg',0)

cv2.namedWindow('image', cv2.WINDOW_NORMAL)
cv2.imshow('image',img)
cv2.waitKey(0) 
cv2.destroyAllWindows()import numpy as np
import cv2

img = cv2.imread('messi5.jpg',0)

cv2.namedWindow('image', cv2.WINDOW_NORMAL)
cv2.imshow('image',img)
cv2.waitKey(0) 
cv2.destroyAllWindows()

Unfortunately I'm not able to dislpay image and getting errors such as

Traceback (most recent call last):

  File "<ipython-input-1-0d251b5710ac>", line 1, in <module>
    runfile('C:/Python27/Scripts/untitled1.py', wdir='C:/Python27/Scripts')

  File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 685, in runfile
    execfile(filename, namespace)


  File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 71, in execfile
    exec(compile(scripttext, filename, 'exec'), glob, loc)

  File "C:/Python27/Scripts/untitled1.py", line 14, in <module>
    cv2.imshow('image',img)

error: ..\..\..\modules\highgui\src\window.cpp:269: error: (-215) size.width>0 && size.height>0 in function cv::imshow

what;s the propoer way to handle images and displaying hem in python?

Thank you. Peter

2016-01-22 14:44:37 -0500 asked a question Compilation error

Dears,

I got latest OpenCV sources from github. I got error compiling it:

Scanning dependencies of target opencv_videoio
[ 37%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap.cpp.obj
[ 37%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_images.cpp.obj
[ 37%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_mjpeg_encoder.cpp.obj
[ 37%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_mjpeg_decoder.cpp.obj
[ 37%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_cmu.cpp.obj
[ 37%] Building CXX object modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_dshow.cpp.obj
In file included from C:\tmp\opencv_latest\opencv\modules\videoio\src\cap_dshow.cpp:337:0:
C:\tmp\opencv_latest\opencv\modules\videoio\src\cap_dshow.cpp: In member function 'void videoInput::getMediaSubtypeAsString(GUID, char*)':
C:\tmp\opencv_latest\opencv\modules\videoio\src\cap_dshow.cpp:2187:41: error: 'sprintf_instead_use_StringCbPrintfA_or_StringCchPrintfA' was not declared in this scope
     if( type == MEDIASUBTYPE_RGB24)     sprintf(tmpStr, "RGB24");
                                         ^
C:\tmp\opencv_latest\opencv\modules\videoio\src\cap_dshow.cpp:2187:57: warning: left operand of comma operator has no effect [-Wunused-value]
     if( type == MEDIASUBTYPE_RGB24)     sprintf(tmpStr, "RGB24");

.
.
.
.
.
.
.

C:\tmp\opencv_latest\opencv\modules\videoio\src\cap_dshow.cpp:2323:31: warning: right operand of comma operator has no effect [-Wunused-value]
     else sprintf(tmpStr, "%u",prop);
                               ^
In file included from C:\tmp\opencv_latest\opencv\modules\videoio\src\cap_dshow.cpp:337:0:
C:/mingw-w64/i686-5.3.0-posix-dwarf-rt_v4-rev0/mingw32/i686-w64-mingw32/include/strsafe.h: At global scope:
C:/mingw-w64/i686-5.3.0-posix-dwarf-rt_v4-rev0/mingw32/i686-w64-mingw32/include/strsafe.h:507:12: warning: inline function 'HRESULT StringCbVPrintfA(STRSAFE_LPSTR, size_t, STRSAFE_LPCSTR, va_list)' used but never defined
 STRSAFEAPI StringCbVPrintfA(STRSAFE_LPSTR pszDest,size_t cbDest,STRSAFE_LPCSTR pszFormat,va_list argList);
            ^
modules\videoio\CMakeFiles\opencv_videoio.dir\build.make:187: recipe for target 'modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_dshow.cpp.obj' failed
mingw32-make[2]: *** [modules/videoio/CMakeFiles/opencv_videoio.dir/src/cap_dshow.cpp.obj] Error 1
CMakeFiles\Makefile2:4420: recipe for target 'modules/videoio/CMakeFiles/opencv_videoio.dir/all' failed
mingw32-make[1]: *** [modules/videoio/CMakeFiles/opencv_videoio.dir/all] Error 2
Makefile:159: recipe for target 'all' failed
mingw32-make: *** [all] Error 2

C:\tmp\opencv_latest\build>

Can anyone help me what issue is it?

Thank you.

Best regards, Peter

2015-12-20 03:48:30 -0500 asked a question python & imshow with pyplot

Hello all,

I'm trying to get running this example

import numpy as np
import cv2
from matplotlib import pyplot as plt

img = cv2.imread('messi5.jpg',0)
plt.imshow(img, cmap = 'gray', interpolation = 'bicubic')
plt.xticks([]), plt.yticks([])  # to hide tick values on X and Y axis
plt.show()

Examples shows image but the code at plt.show() get stopped and now further command promt avialable from python. I'm running it within

Python 2.7.10 (default, May 23 2015, 09:40:32) [MSC v.1500 32 bit (Intel)] on win32

Thank you for your advice.

Regards,Peter

2015-10-02 05:11:26 -0500 commented question protobuf opencv_contrib

I did report an issue. I use CMake GUI howto do "cmake -DBUILD_opencv_dnn=OFF" within GUI?

2015-10-02 03:49:35 -0500 asked a question protobuf opencv_contrib

Dears,

I'm trying to compile opencv_contrib and I am getting errors as follows

[ 54%] Building CXX object modules/dnn/3rdparty/protobuf/CMakeFiles/libprotobuf.dir/src/google/protobuf/compiler/importer.cc.obj
In file included from  C:\opencv\sources_contrib\modules\dnn\3rdparty\protobuf\src\google\protobuf\compiler\importer.cc:38:0:
c:\mingw\include\unistd.h:78:11: error: '_cdecl' does not name a type
 _EXTERN_C _cdecl __MINGW_NOTHROW
           ^
In file included from C:\opencv\sources_contrib\modules\dnn\3rdparty\protobuf\src\google\protobuf\compiler\importer.cc:38:0:
c:\mingw\include\unistd.h:104:1: error: '_cdecl' does not name a type
 _cdecl __MINGW_NOTHROW
 ^
c:\mingw\include\unistd.h: In function 'int nanosleep(const timespec*, timespec*)':
c:\mingw\include\unistd.h:114:51: error: '__mingw_sleep' was not declared in this scope
     ? (unsigned)(-1) : (unsigned)(period->tv_nsec));
                                                   ^
c:\mingw\include\unistd.h: At global scope:
c:\mingw\include\unistd.h:125:28: error: expected initializer before 'usleep'
 int _cdecl __MINGW_NOTHROW usleep( useconds_t )__MINGW_ATTRIB_DEPRECATED;
                            ^
c:\mingw\include\unistd.h: In function 'int usleep(useconds_t)':
c:\mingw\include\unistd.h:129:73: error: '__mingw_sleep' was not declared in this scope
 int usleep( useconds_t period ){ return __mingw_sleep( 0, 1000 * period ); }
                                                                         ^
c:\mingw\include\unistd.h: At global scope:
c:\mingw\include\unistd.h:138:33: error: expected initializer before 'sleep'
 unsigned _cdecl __MINGW_NOTHROW sleep( unsigned );
                                 ^
c:\mingw\include\unistd.h: In function 'unsigned int sleep(unsigned int)':
c:\mingw\include\unistd.h:142:68: error: '__mingw_sleep' was not declared in this scope
 unsigned sleep( unsigned period ){ return __mingw_sleep( period, 0 ); }
                                                                    ^
c:\mingw\include\unistd.h: At global scope:
c:\mingw\include\unistd.h:153:12: error: expected initializer before 'ftruncate'
 int _cdecl ftruncate( int, off_t );
            ^
In file included from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\cmath:44:0,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\random:38,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\bits\stl_algo.h:65,
                 from c:\mingw\lib\gcc\mingw32\4.8.1\include\c++\algorithm:62,
                 from C:\opencv\sources_contrib\modules\dnn\3rdparty\protobuf\src\google\protobuf\compiler\importer.cc:45:
c:\mingw\include\math.h: In function 'float hypotf(float, float)':
c:\mingw\include\math.h:635:30: error: '_hypot' was not declared in this scope
 { return (float)(_hypot (x, y)); }
                              ^
modules\dnn\3rdparty\protobuf\CMakeFiles\libprotobuf.dir\build.make:62: recipe for target 'modules/dnn/3rdparty/protobuf/CMakeFiles/libprotobuf.dir/src/google/protobuf/compiler/importer.cc.obj' failed
mingw32-make[2]: *** [modules/dnn/3rdparty/protobuf/CMakeFiles/libprotobuf.dir/src/google/protobuf/compiler/importer.cc.obj] Error 1
CMakeFiles\Makefile2:5306: recipe for target 'modules/dnn/3rdparty/protobuf/CMakeFiles/libprotobuf.dir/all' failed
mingw32-make[1]: *** [modules/dnn/3rdparty/protobuf/CMakeFiles/libprotobuf.dir/all] Error 2
Makefile:148: recipe for target 'all' failed
mingw32-make: *** [all] Error 2

Did you experienced such behavior? Is there any solution for this?

Thank you.

Best regards.

2015-09-22 13:11:26 -0500 asked a question Qt & OpenCV @ Eclipse

Dears,

I'd like to use Qt with OpenCV and use Eclipse as IDE. Now I did not build OpenCV WITH_QT option. Do I need to rebuild OpenCV WITH_QT option to be able to use Qt? What WITH_QT option real means?

Thank you for your advice.

Best regards, Peter