Как в Ubuntu установить OpenCV

Хотя

 dpkg -l | grep libopencv

выдало :

ii  libopencv-calib3d-dev:amd64                4.2.0+dfsg-5                        amd64        development files for libopencv-calib3d4.2
ii  libopencv-calib3d4.2:amd64                 4.2.0+dfsg-5                        amd64        computer vision Camera Calibration library
ii  libopencv-contrib-dev:amd64                4.2.0+dfsg-5                        amd64        development files for libopencv-contrib4.2
ii  libopencv-contrib4.2:amd64                 4.2.0+dfsg-5                        amd64        computer vision contrlib library
ii  libopencv-core-dev:amd64                   4.2.0+dfsg-5                        amd64        development files for libopencv-core4.2
ii  libopencv-core4.2:amd64                    4.2.0+dfsg-5                        amd64        computer vision core library
ii  libopencv-dev                              4.2.0+dfsg-5                        amd64        development files for opencv
ii  libopencv-dnn-dev:amd64                    4.2.0+dfsg-5                        amd64        development files for libopencv-dnn4.2
ii  libopencv-dnn4.2:amd64                     4.2.0+dfsg-5                        amd64        computer vision Deep neural network module
ii  libopencv-features2d-dev:amd64             4.2.0+dfsg-5                        amd64        development files for libopencv-features2d4.2
ii  libopencv-features2d4.2:amd64              4.2.0+dfsg-5                        amd64        computer vision Feature Detection and Descriptor Extraction library
ii  libopencv-flann-dev:amd64                  4.2.0+dfsg-5                        amd64        development files for libopencv-flann4.2
ii  libopencv-flann4.2:amd64                   4.2.0+dfsg-5                        amd64        computer vision Clustering and Search in Multi-Dimensional spaces library
ii  libopencv-highgui-dev:amd64                4.2.0+dfsg-5                        amd64        development files for libopencv-highgui4.2
ii  libopencv-highgui4.2:amd64                 4.2.0+dfsg-5                        amd64        computer vision High-level GUI and Media I/O library
ii  libopencv-imgcodecs-dev:amd64              4.2.0+dfsg-5                        amd64        development files for libopencv-imgcodecs4.2
ii  libopencv-imgcodecs4.2:amd64               4.2.0+dfsg-5                        amd64        computer vision Image Codecs library
ii  libopencv-imgproc-dev:amd64                4.2.0+dfsg-5                        amd64        development files for libopencv-imgproc4.2
ii  libopencv-imgproc4.2:amd64                 4.2.0+dfsg-5                        amd64        computer vision Image Processing library

может что то и стоит. Похоже установилось, но не в ту папку, нежеле в 18 убунте.