Python OpenCV 包与 Linux 不兼容？
Python OpenCV package not compatible with Linux?
我在 windows 上测试了一些代码，效果很好。在我的 VPS (Debian) 上导出它时，我遇到了一些错误。这是否意味着它根本不可能在 linux 上运行（我对此无能为力？）？
这是我在包裹页面上找到的内容：
MacOS and Linux wheels have currently some limitations:
- video related functionality is not supported (not compiled with FFmpeg)
- for example ``cv2.imshow()`` will not work (not compiled with GTK+ 2.x or Carbon support)
这是输出错误：
root@vps324173:~/Test# python main.py
* Running on http://myserverip:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
* Debugger PIN: 296-193-487
myclientip - - [05/May/2017 04:33:52] "GET / HTTP/1.1" 200 -
a
OpenCV Error: Unknown error code -10 (Raw image encoder error: Empty JPEG image (DNL not supported)) in throwOnEror, file /io/opencv/modules/imgcodecs/src/grfmt_base.cpp, line 139
OpenCV Error: Unknown error code -10 (Raw image encoder error: Empty JPEG image (DNL not supported)) in throwOnEror, file /io/opencv/modules/imgcodecs/src/grfmt_base.cpp, line 139
Debugging middleware caught exception in streamed response at a point where response headers were already sent.
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/werkzeug/wsgi.py", line 704, in __next__
return self._next()
File "/usr/local/lib/python2.7/dist-packages/werkzeug/wrappers.py", line 81, in _iter_encoded
for item in iterable:
File "/root/Test/main.py", line 14, in gen
frame = camera.get_frame()
File "/root/Test/camera.py", line 42, in get_frame
ret, jpeg = cv2.imencode('.jpg', image)
error: /io/opencv/modules/imgcodecs/src/grfmt_base.cpp:139: error: (-10) Raw image encoder error: Empty JPEG image (DNL not supported) in function throwOnEror
myclientip - - [05/May/2017 04:33:52] "GET /video_feed HTTP/1.1" 200 -
感谢您的帮助！
你说的可能是pypi中的opencv-python。这是一个非常具有误导性的项目（经常在 pypi、成熟等中找到），可能对一些难以安装 opencv 的纯 OS 有用。不要在 Debian 风格上使用它 Linux。进一步说明：
- python-opencv 是 Debian 软件包（推荐，包含视频支持）
- opencv-python是外部项目（不推荐，集成的opencv缺少视频支持）
所以对于 Debian(,..) 我们有这些可能性：
从 Debian 软件包安装
sudo aptitude install libopencv-dev python-opencv
# /usr/lib/python2.7/dist-packages/cv2.x86_64-linux-gnu.so
sudo aptitude purge libopencv-dev python-opencv # uninstall
从源安装 (github.com/opencv/opencv):
默认支持视频（有关详细信息，请参阅 cmake 的 WITH_FFMPEG 标志）
sudo aptitude install build-essential cmake
sudo aptitude install python-dev python-numpy
sudo aptitude install libavdevice-dev libavformat-dev libavfilter-dev libavcodec-dev libswscale-dev libavutil-dev
sudo aptitude install libgtk2.0-common libgtk2.0-bin libgtk2.0-dev libdc1394-22-dev libv4l-dev libgstreamer-plugins-base1.0-dev
sudo pip install cmake
mkdir build/
cd build/
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..
# check output if FFMPEG status is YES
make
sudo make install --or-- sudo checkinstall --pkgname opencv
# /usr/local/lib/python2.7/dist-packages/cv2.so
sudo make uninstall --or-- sudo dpkg -r opencv # uninstall
opencv-python项目（不用用！）：opencv WITHOUT VIDEO support
sudo pip install opencv-python
# /usr/local/lib/python2.7/dist-packages/cv2/cv2.so
sudo pip uninstall opencv-python # uninstall
编解码器语法：
try:
codec = cv2.VideoWriter_fourcc(*'MJPG') # newer syntax
except AttributeError:
codec = cv2.cv.CV_FOURCC(*'MJPG') # older syntax
我在 windows 上测试了一些代码，效果很好。在我的 VPS (Debian) 上导出它时，我遇到了一些错误。这是否意味着它根本不可能在 linux 上运行（我对此无能为力？）？
这是我在包裹页面上找到的内容：
MacOS and Linux wheels have currently some limitations:
- video related functionality is not supported (not compiled with FFmpeg)
- for example ``cv2.imshow()`` will not work (not compiled with GTK+ 2.x or Carbon support)
这是输出错误：
root@vps324173:~/Test# python main.py
* Running on http://myserverip:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
* Debugger PIN: 296-193-487
myclientip - - [05/May/2017 04:33:52] "GET / HTTP/1.1" 200 -
a
OpenCV Error: Unknown error code -10 (Raw image encoder error: Empty JPEG image (DNL not supported)) in throwOnEror, file /io/opencv/modules/imgcodecs/src/grfmt_base.cpp, line 139
OpenCV Error: Unknown error code -10 (Raw image encoder error: Empty JPEG image (DNL not supported)) in throwOnEror, file /io/opencv/modules/imgcodecs/src/grfmt_base.cpp, line 139
Debugging middleware caught exception in streamed response at a point where response headers were already sent.
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/werkzeug/wsgi.py", line 704, in __next__
return self._next()
File "/usr/local/lib/python2.7/dist-packages/werkzeug/wrappers.py", line 81, in _iter_encoded
for item in iterable:
File "/root/Test/main.py", line 14, in gen
frame = camera.get_frame()
File "/root/Test/camera.py", line 42, in get_frame
ret, jpeg = cv2.imencode('.jpg', image)
error: /io/opencv/modules/imgcodecs/src/grfmt_base.cpp:139: error: (-10) Raw image encoder error: Empty JPEG image (DNL not supported) in function throwOnEror
myclientip - - [05/May/2017 04:33:52] "GET /video_feed HTTP/1.1" 200 -
感谢您的帮助！
你说的可能是pypi中的opencv-python。这是一个非常具有误导性的项目（经常在 pypi、成熟等中找到），可能对一些难以安装 opencv 的纯 OS 有用。不要在 Debian 风格上使用它 Linux。进一步说明：
- python-opencv 是 Debian 软件包（推荐，包含视频支持）
- opencv-python是外部项目（不推荐，集成的opencv缺少视频支持）
所以对于 Debian(,..) 我们有这些可能性：
从 Debian 软件包安装
sudo aptitude install libopencv-dev python-opencv
# /usr/lib/python2.7/dist-packages/cv2.x86_64-linux-gnu.so
sudo aptitude purge libopencv-dev python-opencv # uninstall
从源安装 (github.com/opencv/opencv):
默认支持视频（有关详细信息，请参阅 cmake 的 WITH_FFMPEG 标志）
sudo aptitude install build-essential cmake
sudo aptitude install python-dev python-numpy
sudo aptitude install libavdevice-dev libavformat-dev libavfilter-dev libavcodec-dev libswscale-dev libavutil-dev
sudo aptitude install libgtk2.0-common libgtk2.0-bin libgtk2.0-dev libdc1394-22-dev libv4l-dev libgstreamer-plugins-base1.0-dev
sudo pip install cmake
mkdir build/
cd build/
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..
# check output if FFMPEG status is YES
make
sudo make install --or-- sudo checkinstall --pkgname opencv
# /usr/local/lib/python2.7/dist-packages/cv2.so
sudo make uninstall --or-- sudo dpkg -r opencv # uninstall
opencv-python项目（不用用！）：opencv WITHOUT VIDEO support
sudo pip install opencv-python
# /usr/local/lib/python2.7/dist-packages/cv2/cv2.so
sudo pip uninstall opencv-python # uninstall
编解码器语法：
try:
codec = cv2.VideoWriter_fourcc(*'MJPG') # newer syntax
except AttributeError:
codec = cv2.cv.CV_FOURCC(*'MJPG') # older syntax