This article will describe building and installing OpenCV 3.1.
Table of Contents
1 Build and install OpenCV
Install package required by OpenCV 2.4 of Ubuntu 16.04.
sudo apt-get build-dep -y opencv
Build and install OpenCV 3.1. OpenCV 3.1 will be installed to /usr/local, so please run export LD_LIBRARY_PATH=/usr/local/lib.
$ sudo apt-get build-dep -y opencv $ git clone https://github.com/Itseez/opencv $ cd opencv $ git checkout 3.1.0 -b 3.1.0 $ cmake -G 'Unix Makefiles' \ -DCMAKE_VERBOSE_MAKEFILE=ON \ -DCMAKE_BUILD_TYPE=Release \ -DBUILD_EXAMPLES=ON \ -DINSTALL_C_EXAMPLES=ON \ -DINSTALL_PYTHON_EXAMPLES=ON \ -DBUILD_NEW_PYTHON_SUPPORT=ON \ -DWITH_FFMPEG=ON \ -DWITH_GSTREAMER=OFF \ -DWITH_GTK=ON \ -DWITH_JASPER=ON \ -DWITH_JPEG=ON \ -DWITH_PNG=ON \ -DWITH_TIFF=ON \ -DWITH_OPENEXR=ON \ -DWITH_PVAPI=ON \ -DWITH_UNICAP=OFF \ -DWITH_EIGEN=ON \ -DWITH_XINE=OFF \ -DBUILD_TESTS=OFF \ -DCMAKE_SKIP_RPATH=ON \ -DWITH_CUDA=OFF \ -DENABLE_PRECOMPILED_HEADERS=OFF \ -DENABLE_SSE=ON -DENABLE_SSE2=ON -DENABLE_SSE3=OFF \ -DWITH_OPENGL=ON -DWITH_TBB=ON -DWITH_1394=ON -DWITH_V4L=ON $ make && sudo make install
2 Excecution result
Trying to create thumbnail from movie with OpenCV python. Interface cv2.cv in OpenCV 2.4 is changed to cv2 in OpenCV 3.1.
#!/usr/bin/env python
import sys
import cv2
def create_thumbnail(movie_name, image_name):
capture = cv2.VideoCapture(movie_name)
max_frame = int(capture.get(cv2.CAP_PROP_FRAME_COUNT))
half_frame = max_frame // 2
capture.set(cv2.CAP_PROP_POS_FRAMES, half_frame)
retval, image = capture.read()
if not retval:
return False
cv2.imwrite(image_name, image)
return True
if __name__ == '__main__':
argv = sys.argv
if len(argv) != 3:
print('Create thumbnail of movie at half position.')
print('usage: %s [Input movie] [Output thumbnail]' % argv[0])
exit(1)
create_thumbnail(argv[1], argv[2])
PNG file is created from MP4 file.
$ export LD_LIBRARY_PATH=/usr/local/lib $ python create-thumbnaiil.py input.mp4 output.png $ file output.png output.png: PNG image data, 480 x 360, 8-bit/color RGB, non-interlaced