编译opencv for android

build opencv for android

1）add script ‘android_hard.sh’ to ‘opencv-3.1.0/platforms/scripts/’

#!/bin/sh
cd `dirname $0`/..

mkdir -p build_android_arm
cd build_android_arm

cmake -DANDROID_ABI="armeabi-v7a-hard with NEON" \
-DANDROID_NATIVE_API_LEVEL=android-19 \
-DBUILD_ANDROID_EXAMPLES=OFF \
-DBUILD_DOCS=OFF \
-DBUILD_EXAMPLES=OFF \
-DWITH_CUDA=OFF \
-DCMAKE_BUILD_WITH_INSTALL_RPATH=ON \
-DCMAKE_TOOLCHAIN_FILE=../android/android.toolchain.cmake $@ ../..

2）run ‘./android_hard.sh’

# if libopencv_java3.so were not to be built
# run the following commends at first
# then re-run 'android_hard.sh'
sudo apt-get install libeigen3-dev
sudo apt-get install ant

3）cd build_android_arm

4）make -j4

5）make install