1. Install OpenCV in Ubuntu:

(1) Update the list of package repositories:

(2) Remove prevIoUsly installed FFMPEG and x264 libraries:

(4) Make a directory to download and build OpenCV:

(5) Download the OpenCV sources for Linux,then unzip it:

(6) Create a directory to compile the OpenCV sources:

(7) Building OpenCV sources with CMake and install:

(8) Make and install:

(9) Restart the system for everything to take effect:

2. Test OpenCV in Ubuntu:

(1) Create a directory DisplayImage for test project:

(2) Create DisplayImage.cpp and edit it:

Then edit the DisplayImage.cpp:

(3) Create a CMake file:

Then edit the CMakeLists.txt:

(4) Generate the executable file:

(5) Execute it:

lena.jpg is the test image

ffmpeg error:

cmake ........ -D WITH_FFMPEG=OFF