Cv2.imshow() error

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1

I’ve installed opencv multiple times even compiled it but the error keeps returning.

cv2.imshow(“Frame”,frame)
cv2.error: OpenCV(4.4.0) /tmp/pip-req-build-sfexxcdo/opencv/modules/highgui/src/window.cpp:651: error: (-2:Unspecified error) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function ‘cvShowImage’

so I installed install libgtk2.0-dev and pkg-config, still get this error.
so what’s wrong?
why does it keep returning?
is there a “right” way to install this? because I tried pip install, apt-get install and the compile instructions.

This has been frustrating.
thanks

2

welcome.

run print(cv2.getBuildInformation()) as python code and post the output

you have several options. focus on one.

pip install opencv-python, that should have been built with Qt or GTK. what precisely does it say when you install that (and only that) and try imshow?

3

@ stupidsignup R u using raspberry pi? Ur problem can be solved in 5 minutes. No needed to do pip install opencv-python. U shouldn’t used pip. If u r using python 3 , then u do pip3. The pip is for python 2.

1 Like
4

Already tried that, as I wrote all the things I tried

5

I’ve got python 3 running, terminal doesn’t recognise pip, only pip3. so I already tried that.

6

Decided to remove opencv and go for tensorflow

7

I’m not asking you to try something you tried already. I’m asking you to gather information to track down the problem.

existing packages should have given you GUI capability. if they didn’t, we need to investigate why, not give up and ask for other things to try without knowing what went wrong.

you’re free to build OpenCV yourself. I’d recommend using cmake-gui for configuring variables and seeing the configuration results. it’s not a black box. it tells you why it fails.

as for the pip comment, on linux the naming convention is python3 and pip3 for v3 versions. the tool is canonically called pip and the python 3 version responds to that command on non-linux platforms. it is generally understood not to use python 2 anymore, so there should be no ambiguity.

8

those two libraries aren’t interchangeable. they do mostly different things. the only thing they have in common is inference. tensorflow doesn’t do most of what OpenCV does (image processing and vision algorithms), and OpenCV doesn’t do most of what tensorflow does (e.g. training).

1 Like
9

General configuration for OpenCV 4.5.1 =====================================
Version control: 4.5.1-dirty

Platform:
Timestamp: 2021-01-02T13:00:02Z
Host: Linux 4.15.0-1077-gcp x86_64
CMake: 3.18.4
CMake generator: Unix Makefiles
CMake build tool: /bin/gmake
Configuration: Release

CPU/HW features:
Baseline: SSE SSE2 SSE3
requested: SSE3
Dispatched code generation: SSE4_1 SSE4_2 FP16 AVX AVX2 AVX512_SKX
requested: SSE4_1 SSE4_2 AVX FP16 AVX2 AVX512_SKX
SSE4_1 (15 files): + SSSE3 SSE4_1
SSE4_2 (1 files): + SSSE3 SSE4_1 POPCNT SSE4_2
FP16 (0 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 AVX
AVX (4 files): + SSSE3 SSE4_1 POPCNT SSE4_2 AVX
AVX2 (29 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2
AVX512_SKX (4 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2 AVX_512F AVX512_COMMON AVX512_SKX

C/C++:
Built as dynamic libs?: NO
C++ standard: 11
C++ Compiler: /usr/lib/ccache/compilers/c++ (ver 9.3.1)
C++ flags (Release): -Wl,-strip-all -fsigned-char -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 -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG
C++ flags (Debug): -Wl,-strip-all -fsigned-char -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 -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG
C Compiler: /usr/lib/ccache/compilers/cc
C flags (Release): -Wl,-strip-all -fsigned-char -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 -Wuninitialized -Wno-comment -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG
C flags (Debug): -Wl,-strip-all -fsigned-char -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 -Wuninitialized -Wno-comment -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -g -O0 -DDEBUG -D_DEBUG
Linker flags (Release): -Wl,–exclude-libs,libippicv.a -Wl,–exclude-libs,libippiw.a -L/root/ffmpeg_build/lib -Wl,–gc-sections -Wl,–as-needed
Linker flags (Debug): -Wl,–exclude-libs,libippicv.a -Wl,–exclude-libs,libippiw.a -L/root/ffmpeg_build/lib -Wl,–gc-sections -Wl,–as-needed
ccache: YES
Precompiled headers: NO
Extra dependencies: ade Qt5::Core Qt5::G ui Qt5::Widgets Qt5::Test Qt5::Concurrent /lib64/libpng.so /lib64/libz.so dl m pthread rt
3rdparty dependencies: ittnotify libprotobuf libjpeg-turbo libwebp libtiff libopenjp2 IlmImf quirc ippiw ippicv

OpenCV modules:
To be built: calib3d core dnn features2d flann gapi highgui imgcodecs imgproc ml objdetect photo python3 stitching video videoio
Disabled: world
Disabled by dependency: -
Unavailable: java python2 ts
Applications: -
Documentation: NO
Non-free algorithms: NO

GUI:
QT: YES (ver 5.15.0)
QT OpenGL support: NO
GTK+: NO
VTK support: NO

Media I/O:
ZLib: /lib64/libz.so (ver 1.2.7)
JPEG: libjpeg-turbo (ver 2.0.6-62)
WEBP: build (ver encoder: 0x020f)
PNG: /lib64/libpng.so (ver 1.5.13)
TIFF: build (ver 42 - 4.0.10)
JPEG 2000: build (ver 2.3.1)
OpenEXR: build (ver 2.3.0)
HDR: YES
SUNRASTER: YES
PXM: YES
PFM: YES

Video I/O:
DC1394: NO
FFMPEG: YES
avcodec: YES (58.109.100)
avformat: YES (58.61.100)
avutil: YES (56.60.100)
swscale: YES (5.8.100)
avresample: NO
GStreamer: NO
v4l/v4l2: YES (linux/videodev2.h)

Parallel framework: pthreads

Trace: YES (with Intel ITT)

Other third-party libraries:
Intel IPP: 2020.0.0 Gold [2020.0.0]
at: /tmp/pip-req-build-ms668fyv/_skbuild/linux-x86_64-3.8/cmake-build/3rdparty/ippicv/ippicv_lnx/icv
Intel IPP IW: sources (2020.0.0)
at: /tmp/pip-req-build-ms668fyv/_skbuild/linux-x86_64-3.8/cmake-build/3rdparty/ippicv/ippicv_lnx/iw
Lapack: NO
Eigen: NO
Custom HAL: NO
Protobuf: build (3.5.1)

OpenCL: YES (no extra features)
Include path: /tmp/pip-req-build-ms668fyv/opencv/3rdparty/include/opencl/1.2
Link libraries: Dynamic load

Python 3:
Interpreter: /opt/python/cp38-cp38/bin/python (ver 3.8.6)
Libraries: libpython3.8.a (ver 3.8.6)
numpy: /tmp/pip-build-env-qm375ina/overlay/lib/python3.8/site-packages/numpy/core/include (ver 1.17.3)
install path: python

Python (for build): /bin/python2.7

Java:
ant: NO
JNI: NO
Java wrappers: NO
Java tests: NO

Install to: /tmp/pip-req-build-ms668fyv/_skbuild/linux-x86_64-3.8/cmake-install

idk what happend but it’s working now, consider it solved, can’t answer how.

[edit] no wait, still some errors, but the image is showing, cant stop it tho