MacOS 下编译 opencv 3.4.1 （整合opencv_contrib 3.4.1）的Android SDK

在opencv 3+的版本中，由于将SIFT，SURF这些有专利的算法单独提取到了opencv_contrib模块，所以按照 http://blog.csdn.net/martin20150405/article/details/53284442 （或者 https://www.jianshu.com/p/4864af795969  ）操作之后还是不能在项目中使用 SIFT，SURF算法的。因为官方给出的release版本中没有预先编译 opencv_contrib 至opencv库，要想使用这些算法，我们需要自己编译opencv_contrib opencv源码，从而获得opencv android sdk。

所以编译Opencv Android Sdk的步骤如下：

参考于： http://yangchao.me/post/build-opencv-android-sdk/ 

1. 重要的是 使用： 

https://dl.google.com/android/repository/android-ndk-r10e-darwin-x86_64.zip

以及

http://dl-ssl.google.com/android/repository/tools_r25.2.5-macosx.zip

不使用这两个文件进行编译的话会报错。

并按照 http://yangchao.me/post/build-opencv-android-sdk/ 中的进行替换：

Note: please degrade the Android SDK tools version, 25.2.4 is fine for me http://dl-ssl.google.com/android/repository/tools_r25.2.5-macosx.zip Go to ~/Library/Android/sdk, rename tools to tools.bak, then unzip the tools_rxxx.zip to sdk/tools directory. Why? because otherwise, android command has been deprecated)

这篇文章安装的是3.3.1版本，在我这边3.4.1以下的版本都会失败，会报一个 ninja的错误。上网查了很久，发现这是在mac使用ninja编译的opencv bug，这个bug在opencv 3.4.1 中解决了。参考链接：https://github.com/opencv/opencv/pull/10515 

于是将 opencv_contrib 和 opencv都切换到 3.4.1版本，在 opencv的 /Users/xujian/Library/opencv/platforms/android 目录中执行  

> python build_sdk.py /Users/xujian/Library/opencv_android /Users/xujian/Library/opencv --sdk_path=/Users/xujian/Library/Android/sdk --ndk_path=/Users/xujian/Downloads/android-ndk-r10e --extra_modules_path=/Users/xujian/Library/opencv_contrib/modules 

正常开始编译，花了很长的时间，成功生成了整合所有opencv_contrib的opencv android sdk。最后将生成的Android sdk（我的在文件夹 /Users/xujian/Library/opencv_android/OpenCV-android-sdk 下）引入android studio项目（引入的步骤还是跟 http://blog.csdn.net/martin20150405/article/details/53284442 这篇博文相同 ），测试SURF算法成功。

最后附上我编译出来的 opencv android sdk文件（基于opencv 3.4.1 编译，系统：macOS 10.13.3）：

 http://download.csdn.net/download/u010671073/10263482 

附上我最终的 CMakeLists.txt 文件：

# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html

# Sets the minimum version of CMake required to build the native library.

cmake_minimum_required(VERSION 3.4.1)

# opencv config
set(CMAKE_VERBOSE_MAKEFILE on)
set(libs "${CMAKE_SOURCE_DIR}/src/main/jniLibs")
include_directories(${CMAKE_SOURCE_DIR}/src/main/cpp/include)

add_library(libopencv_java3 SHARED IMPORTED )
set_target_properties(libopencv_java3 PROPERTIES
    IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_java3.so")

#add_library(libopencv_java SHARED IMPORTED )
#set_target_properties(libopencv_java PROPERTIES
#    IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_java.so")

add_library(libopencv_saliency STATIC IMPORTED )
set_target_properties(libopencv_saliency PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_saliency.a")

add_library(libopencv_photo STATIC IMPORTED )
set_target_properties(libopencv_photo PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_photo.a")

add_library(libopencv_bgsegm STATIC IMPORTED )
set_target_properties(libopencv_bgsegm PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_bgsegm.a")

add_library(libopencv_videoio STATIC IMPORTED )
set_target_properties(libopencv_videoio PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_videoio.a")

add_library(libopencv_surface_matching STATIC IMPORTED )
set_target_properties(libopencv_surface_matching PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_surface_matching.a")

add_library(libopencv_datasets STATIC IMPORTED )
set_target_properties(libopencv_datasets PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_datasets.a")

add_library(libopencv_dnn_objdetect STATIC IMPORTED )
set_target_properties(libopencv_dnn_objdetect PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_dnn_objdetect.a")

add_library(libopencv_calib3d STATIC IMPORTED )
set_target_properties(libopencv_calib3d PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_calib3d.a")

add_library(libopencv_xphoto STATIC IMPORTED )
set_target_properties(libopencv_xphoto PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_xphoto.a")

add_library(libopencv_features2d STATIC IMPORTED )
set_target_properties(libopencv_features2d PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_features2d.a")

add_library(libopencv_img_hash STATIC IMPORTED )
set_target_properties(libopencv_img_hash PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_img_hash.a")

add_library(libopencv_dnn STATIC IMPORTED )
set_target_properties(libopencv_dnn PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_dnn.a")

add_library(libopencv_core STATIC IMPORTED )
set_target_properties(libopencv_core PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_core.a")

add_library(libopencv_rgbd STATIC IMPORTED )
set_target_properties(libopencv_rgbd PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_rgbd.a")

add_library(libopencv_plot STATIC IMPORTED )
set_target_properties(libopencv_plot PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_plot.a")

add_library(libopencv_imgcodecs STATIC IMPORTED )
set_target_properties(libopencv_imgcodecs PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_imgcodecs.a")

add_library(libopencv_highgui STATIC IMPORTED )
set_target_properties(libopencv_highgui PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_highgui.a")

add_library(libopencv_fuzzy STATIC IMPORTED )
set_target_properties(libopencv_fuzzy PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_fuzzy.a")

add_library(libopencv_structured_light STATIC IMPORTED )
set_target_properties(libopencv_structured_light PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_structured_light.a")

add_library(libopencv_video STATIC IMPORTED )
set_target_properties(libopencv_video PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_video.a")

add_library(libopencv_tracking STATIC IMPORTED )
set_target_properties(libopencv_tracking PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_tracking.a")

add_library(libopencv_superres STATIC IMPORTED )
set_target_properties(libopencv_superres PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_superres.a")

add_library(libopencv_reg STATIC IMPORTED )
set_target_properties(libopencv_reg PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_reg.a")

add_library(libopencv_xobjdetect STATIC IMPORTED )
set_target_properties(libopencv_xobjdetect PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_xobjdetect.a")

add_library(libopencv_text STATIC IMPORTED )
set_target_properties(libopencv_text PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_text.a")

add_library(libopencv_ml STATIC IMPORTED )
set_target_properties(libopencv_ml PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_ml.a")

add_library(libopencv_ccalib STATIC IMPORTED )
set_target_properties(libopencv_ccalib PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_ccalib.a")

add_library(libopencv_objdetect STATIC IMPORTED )
set_target_properties(libopencv_objdetect PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_objdetect.a")

add_library(libopencv_stereo STATIC IMPORTED )
set_target_properties(libopencv_stereo PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_stereo.a")

add_library(libopencv_videostab STATIC IMPORTED )
set_target_properties(libopencv_videostab PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_videostab.a")

add_library(libopencv_aruco STATIC IMPORTED )
set_target_properties(libopencv_aruco PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_aruco.a")

add_library(libopencv_face STATIC IMPORTED )
set_target_properties(libopencv_face PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_face.a")

add_library(libopencv_stitching STATIC IMPORTED )
set_target_properties(libopencv_stitching PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_stitching.a")

add_library(libopencv_phase_unwrapping STATIC IMPORTED )
set_target_properties(libopencv_phase_unwrapping PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_phase_unwrapping.a")

add_library(libopencv_xfeatures2d STATIC IMPORTED )
set_target_properties(libopencv_xfeatures2d PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_xfeatures2d.a")

add_library(libopencv_ximgproc STATIC IMPORTED )
set_target_properties(libopencv_ximgproc PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_ximgproc.a")

add_library(libopencv_shape STATIC IMPORTED )
set_target_properties(libopencv_shape PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_shape.a")

add_library(libopencv_line_descriptor STATIC IMPORTED )
set_target_properties(libopencv_line_descriptor PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_line_descriptor.a")

add_library(libopencv_dpm STATIC IMPORTED )
set_target_properties(libopencv_dpm PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_dpm.a")

add_library(libopencv_flann STATIC IMPORTED )
set_target_properties(libopencv_flann PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_flann.a")

add_library(libopencv_hfs STATIC IMPORTED )
set_target_properties(libopencv_hfs PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_hfs.a")

add_library(libopencv_bioinspired STATIC IMPORTED )
set_target_properties(libopencv_bioinspired PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_bioinspired.a")

add_library(libopencv_imgproc STATIC IMPORTED )
set_target_properties(libopencv_imgproc PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_imgproc.a")

add_library(libopencv_optflow STATIC IMPORTED )
set_target_properties(libopencv_optflow PROPERTIES IMPORTED_LOCATION "${libs}/${ANDROID_ABI}/libopencv_optflow.a")


set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11 -fexceptions -frtti")


# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             src/main/cpp/native-lib.cpp )

# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              log )

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
                       native-lib
                       android
                       log
                       libopencv_java3
#                       libopencv_java
                       libopencv_saliency
                       libopencv_photo
                       libopencv_bgsegm
                       libopencv_videoio
                       libopencv_surface_matching
                       libopencv_datasets
                       libopencv_dnn_objdetect
                       libopencv_calib3d
                       libopencv_xphoto
                       libopencv_features2d
                       libopencv_img_hash
                       libopencv_dnn
                       libopencv_core
                       libopencv_rgbd
                       libopencv_plot
                       libopencv_imgcodecs
                       libopencv_highgui
                       libopencv_fuzzy
                       libopencv_structured_light
                       libopencv_video
                       libopencv_tracking
                       libopencv_superres
                       libopencv_reg
                       libopencv_xobjdetect
                       libopencv_text
                       libopencv_ml
                       libopencv_ccalib
                       libopencv_objdetect
                       libopencv_stereo
                       libopencv_videostab
                       libopencv_aruco
                       libopencv_face
                       libopencv_stitching
                       libopencv_phase_unwrapping
                       libopencv_xfeatures2d
                       libopencv_ximgproc
                       libopencv_shape
                       libopencv_line_descriptor
                       libopencv_dpm
                       libopencv_flann
                       libopencv_hfs
                       libopencv_bioinspired
                       libopencv_imgproc
                       libopencv_optflow
                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )