Dlib 在Android的编译

Dlib 在Android的编译

1.首先下载最新的Dlib源码，地址：http://dlib.net, 代码依赖一个模型,下载地址：http://dlib.net/files/shape_predictor_68_face_landmarks.dat.bz2

2.新建一个Native C++的工程，如图所示:

3.把第一步下载的文件全部copy到cpp下面，如图所示：

4.如下修改CMakeLists.txt

​

# 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)

set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -s -03 -Wall")
set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -s -03 -Wall")

include(./dlib-19.19/dlib/cmake)

add_library( # Sets the name of the library.
        bzfacetrack
        # Sets the library as a shared library.
        SHARED

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

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)

target_link_libraries( # Specifies the target library.
        bzfacetrack

        # Links the target library to the log library
        # included in the NDK.
        dlib ${log-lib} android jnigraphics)

5.最后写测试代码,把第一步下载的模型文件shape_predictor_68_face_landmarks.dat放到SD卡上，测试代码用到的IMG_25_small.jpg，是一张包含人脸的图片，请自行准备，这个代码运行一次需要20秒左右，后续代码会优化，请持续关注

#include 
#include 
#include 
#include 
#include 
#include 
#include "common/BZLogUtil.h"
#include "common/bz_time.h"

using namespace dlib;
using namespace std;

int test_face_landmark() {
// We need a face detector.  We will use this to get bounding boxes for
    // each face in an image.
    frontal_face_detector detector = get_frontal_face_detector();
    // And we also need a shape_predictor.  This is the tool that will predict face
    // landmark positions given an image and face bounding box.  Here we are just
    // loading the model from the shape_predictor_68_face_landmarks.dat file you gave
    // as a command line argument.

    int64_t startTime = getCurrentTime();
    shape_predictor sp;
    deserialize("/sdcard/bzmedia/shape_predictor_68_face_landmarks.dat") >> sp;
    BZLogUtil::logD("deserialize 耗时=%lld", getCurrentTime() - startTime);

    array2d img;
//    load_image(img, "/sdcard/bzmedia/IMG_25.jpg");
    load_image(img, "/sdcard/bzmedia/IMG_25_small.jpg");

    // Now tell the face detector to give us a list of bounding boxes
    // around all the faces in the image.
    startTime = getCurrentTime();
    std::vector dets = detector(img);
    BZLogUtil::logD("detector 耗时=%lld", getCurrentTime() - startTime);

    BZLogUtil::logD("Number of faces detected: %lld", dets.size());

    // Now we will go ask the shape_predictor to tell us the pose of
    // each face we detected.
    std::vector shapes;
    for (unsigned long j = 0; j < dets.size(); ++j) {
        startTime = getCurrentTime();
        full_object_detection shape = sp(img, dets[j]);
        BZLogUtil::logD("sp 耗时=%lld", getCurrentTime() - startTime);

        BZLogUtil::logD("number of parts: %d", shape.num_parts());
        BZLogUtil::logD("pixel position of first part: x=%ld y=%ld", shape.part(0).x(),
                        shape.part(0).y());
        BZLogUtil::logD("pixel position of second part: x=%ld y=%ld", shape.part(1).x(),
                        shape.part(1).y());
        shapes.push_back(shape);
    }

    BZLogUtil::logD("---finish---");
    return 0;
}

extern "C" JNIEXPORT jint JNICALL
Java_com_luoye_dlibdemo_MainActivity_nativeTest(
        JNIEnv *env,
        jobject /* this */) {

    test_face_landmark();

    return 0;
}

6.修改build.gradle，如下，修改cmake，ndk：

 defaultConfig {
        applicationId "com.luoye.dlibdemo"
        minSdkVersion 17
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                arguments '-DANDROID_PLATFORM=android-16', '-DANDROID_TOOLCHAIN=clang',
                        '-DANDROID_STL=c++_static', '-DDLIB_NO_GUI_SUPPORT=1', '-DCMAKE_BUILD_TYPE=Release ..'
                cppFlags "-std=c++11 -o3", '-frtti', '-fexceptions'
            }
        }
        ndk {
            abiFilters 'armeabi-v7a', 'arm64-v8a'
        }
    }

7.至此已经完成编译测试，代码地址https://github.com/bookzhan/bzdlib.git，在分支dlib_src上，请注意区分