Ubuntu 20.04 LTS 安装OpenCV 4.5.5

1 安装FFmpeg

wget http://ffmpeg.org/releases/ffmpeg-4.4.1.tar.bz2
tar jxvf ffmpeg-4.4.1.tar.bz2 
cd ffmpeg-4.4.1/
./configure --enable-shared --prefix=/usr/local/ffmpeg
make
make install

在/etc/profile中添加以下内容：

export LD_LIBRARY_PATH=/usr/local/ffmpeg/lib:$LD_LIBRARY_PATH
export PKG_CONFIG_PATH=/usr/local/ffmpeg/lib/pkgconfig:$PKG_CONFIG_PATH

2 安装numpy

sudo pip3 install numpy

3 下载ippicv_2020_lnx_intel64_20191018_general.tgz

到这个地址： https://github.com/opencv/opencv_3rdparty/tree/ippicv/master_20191018

按“Download ZIP”的方式下载。将下载下来的文件解压后，从里面拿出ippicv_2020_lnx_intel64_20191018_general.tgz。

4 安装OpenCV

wget https://codeload.github.com/opencv/opencv/zip/4.5.5
mv 4.5.5 opencv-4.5.5.zip
unzip opencv-4.5.5.zip 
cd opencv-4.5.5/

将ippicv_2020_lnx_intel64_20191018_general.tgz 放在opencv-4.5.5/3rdparty/ippicv/下，然后修改ippicv.cmake文件的第42行：

  ocv_download(FILENAME ${OPENCV_ICV_NAME}
               HASH ${OPENCV_ICV_HASH}
               URL
                 "${OPENCV_IPPICV_URL}"
                 "$ENV{OPENCV_IPPICV_URL}"
                 "file:///home/macroice/develop/cpp/opencv-4.5.5/3rdparth/ippicv/"
                 #"https://raw.githubusercontent.com/opencv/opencv_3rdparty/${IPPICV_COMMIT}/ippicv/"
               DESTINATION_DIR "${THE_ROOT}"
               ID IPPICV
               STATUS res
               UNPACK RELATIVE_URL)

继续执行以下命令：

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release \
-DCMAKE_INSTALL_PREFIX=/usr/local/opencv \
-DINSTALL_PYTHON_EXAMPLES=OFF \
-DINSTALL_C_EXAMPLES=OFF \
-DBUILD_EXAMPLES=OFF \
-DBUILD_TEST=OFF \
-DENABLE_FAST_MATH=1 \
-DOPENCV_ENABLE_NONFREE=ON \
-DWITH_TBB=ON ..
make
make install
ln -s /usr/local/opencv/lib/python3.8/site-packages/cv2/python-3.8/cv2.cpython-38-x86_64-linux-gnu.so /usr/local/lib/python3.8/dist-packages/cv2.so

参考

OpenCV: Install OpenCV-Python in Ubuntuhttps://docs.opencv.org/4.5.4/d2/de6/tutorial_py_setup_in_ubuntu.html