Master OpenCV with Pratical Computer Vision Projects——如何编译Cartoonifier_Android

由于《Master OpenCV with Pratical Computer Vision Projects》对其Android例子的环境配置没有详细介绍，所以我通过自己的摸索，把相关经验拿来与大家分享，希望大家能够少走点弯路。

我的环境及对应的保存路径如下：

Cygwin——【C:\Cygwin_】

android-ndk-r9——【C:\Work\android-ndk-r9】（我自己用了r8编译报错，r9却没问题，错误如下所示）

C:/AndroidSDK_Eclipse/android-ndk-r8/toolchains/arm-linux-androideabi-4.4.3/prebuilt/windows/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/ld.exe: ./obj/local/armeabi-v7a/libopencv_contrib.a: No such file: Permission denied
/cygdrive/c/AndroidSDK_Eclipse/android-ndk-r8/build/core/build-binary.mk:369: recipe for target `obj/local/armeabi-v7a/libcartoonifier.so' failed
collect2: ld returned 1 exit status
make: *** [obj/local/armeabi-v7a/libcartoonifier.so] Error 1

OpenCV-2.4.6-android-sdk——【C:\Work\OpenCV4Android\OpenCV-2.4.6-android-sdk】

具体步骤如下：

1.首先，将Cartoonifier_Android放在C:\Work\OpenCV4Android\OpenCV-2.4.6-android-sdk\samples目录下（如果不放在这目录下，需要在Android.mk中更改相应的OpenCV.mk路径），并从Cartoonifier_Desktop中把cartoon.cpp、cartoon.h、ImageUtils_0.7.cpp、ImageUtils.h放在jni目录下；

当然，我们也在该目录下新建一个includeOpenCV.mk文件来指定OpenCV文件的位置，内容如下

OPENCV_MK_PATH:=C:\Work\OpenCV4Android\OpenCV-2.4.6-android-sdk\sdk\native\jni\OpenCV.mk

2.接着，我们来看一下Android.mk文件的中需要修改的内容：

#/****************************************************************************
#*   Cartoonifier, for Android.
#*****************************************************************************
#*   by Shervin Emami, 5th Dec 2012 ([email protected])
#*   http://www.shervinemami.info/
#*****************************************************************************
#*   Ch1 of the book "Mastering OpenCV with Practical Computer Vision Projects"
#*   Copyright Packt Publishing 2012.
#*   http://www.packtpub.com/cool-projects-with-opencv/book
#****************************************************************************/


LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

OPENCV_LIB_TYPE:=STATIC
OPENCV_INSTALL_MODULES:=on

# Path to OpenCV.mk file, which is generated when you build OpenCV for Android.
# include C:\OpenCV\android\build\OpenCV.mk
# include ~/OpenCV/android/build/OpenCV.mk
#include ../includeOpenCV.mk //把这句话注释
include ../../sdk/native/jni/OpenCV.mk //加上这句话，前提是我们的工程是放在OpenCV-2.4.6-android-sdk\samples目录下的
ifeq ("$(wildcard $(OPENCV_MK_PATH))","")
    #try to load OpenCV.mk from default install location
    #include $(TOOLCHAIN_PREBUILT_ROOT)/user/share/OpenCV/OpenCV.mk
else
    #include $(OPENCV_MK_PATH)
endif

LOCAL_MODULE    := cartoonifier
LOCAL_LDLIBS +=  -llog -ldl

# Since we have source + headers files in an external folder, we need to show where they are.
LOCAL_SRC_FILES := jni_part.cpp
LOCAL_SRC_FILES += cartoon.cpp //把desk_top项目中的源文件拷贝到Android目录下一起编译
LOCAL_SRC_FILES += ImageUtils_0.7.cpp
LOCAL_C_INCLUDES += $(LOCAL_PATH)

include $(BUILD_SHARED_LIBRARY)

3.之后，在eclipse的项目属性中选择C/C++ Builder->Environment，并定义NDK和PATH这两个环境变量

4.最后，还需要在Build Path->Configure Build Path中添加opencv library。

5.如果ImageUtils_0.7.cpp报错：format not a string literal and no format arguments，简单的办法只需要把相关的LOG注释掉就行了。

还有一些小细节可能会报错，通过修改project.properties和AndroidManifest.xml就OK了。

通过以上5步就可以右键选择build-all来编译生成动态库了。