【openCV踩坑日记】openCV3.X.X: nonfree模块的安装、调试和使用(SIFT的使用)
opencv2/nonfree的安装
看了好多讲解怎么使用openCV-contrib的nonfree模块的内容，要么整不了，要么太麻烦了，今天花了一下午的时候调试通了，做个记录。(前提是你先安装了openCV_contrib，并且是Ubuntu系统)
要想用SIFT，
就需要#include
但是在编译的时候，会报错：
fatal error: opencv2/nonfree.hpp: No such file or directory
所以说这个时候，你就需要安装openCV的nonfree模块，输入以下内容，
sudo apt-get update
sudo add-apt-repository --yes ppa:xqms/opencv-nonfree
sudo apt-get update
sudo apt-get install libopencv-nonfree-dev
此时会报错：
sudo apt-get install libopencv-nonfree-dev
正在读取软件包列表... 完成
正在分析软件包的依赖关系树
正在读取状态信息... 完成
有一些软件包无法被安装。如果您用的是 unstable 发行版，这也许是
因为系统无法达到您要求的状态造成的。该版本中可能会有一些您需要的软件
包尚未被创建或是它们已被从新到(Incoming)目录移出。
下列信息可能会对解决问题有所帮助：
下列软件包有未满足的依赖关系：
libopencv-nonfree-dev : 依赖: libopencv-features2d-dev (= 2.4.9.1+dfsg-1.5ubuntu1xqms2~xenial1) 但是 2.4.9.1+dfsg-1.5ubuntu1.1 正要被安装
依赖: libopencv-nonfree2.4v5 (= 2.4.9.1+dfsg-1.5ubuntu1xqms2~xenial1) 但是它将不会被安装
E: 无法修正错误，因为您要求某些软件包保持现状，就是它们破坏了软件包间的依赖关系。
这个时候，一般人都会卡住…
解决办法：下载依赖检查的功能强大的包管理工具 aptitude！
sudo apt-get install aptitude
sudo aptitude install libopencv-nonfree-dev
第一个选no，之后的选yes！！！！
说多了都是泪，我当时第一个手太快选了yes，导致ros被删了，又得重新下载ros！可是在下载ros 的时候，即sudo rosdep init 的时候，又出现了Website may be down.的报错！又花了好长时间才解决！
这个办法是在Ubuntu上对缺少依赖的一种万能解法！
然后openCV的nonfree模块就安装成功了！！
对nonfree.hpp的修改
但是，好不容易装完了，谁能想到，编译的时候又会报错：
In file included from /usr/include/opencv2/nonfree/nonfree.hpp:46:0,
from /home/XXX/SLAM/XXX/SLAM/feature_tester/test_on_image/TestOnImage/feature_tester.cpp:8:
/usr/include/opencv2/nonfree/features2d.hpp:73:21: error: ‘vector’ has not been declared
vector<KeyPoint>& keypoints) const;
^
/usr/include/opencv2/nonfree/features2d.hpp:73:27: error: expected ‘,’ or ‘...’ before ‘<’ token
vector<KeyPoint>& keypoints) const;
^
/usr/include/opencv2/nonfree/features2d.hpp:77:21: error: ‘vector’ has not been declared
vector<KeyPoint>& keypoints,
^
/usr/include/opencv2/nonfree/features2d.hpp:77:27: error: expected ‘,’ or ‘...’ before ‘<’ token
vector<KeyPoint>& keypoints,
^
/usr/include/opencv2/nonfree/features2d.hpp:76:10: error: ‘void cv::SIFT::operator()(cv::InputArray, cv::InputArray, int) const’ cannot be overloaded
void operator()(InputArray img, InputArray mask,
^
/usr/include/opencv2/nonfree/features2d.hpp:72:10: error: with ‘void cv::SIFT::operator()(cv::InputArray, cv::InputArray, int) const’
void operator()(InputArray img, InputArray mask,
^
/usr/include/opencv2/nonfree/features2d.hpp:81:5: error: ‘AlgorithmInfo’ does not name a type
AlgorithmInfo* info() const;
^
/usr/include/opencv2/nonfree/features2d.hpp:83:49: error: ‘vector’ has not been declared
void buildGaussianPyramid( const Mat& base, vector<Mat>& pyr, int nOctaves
^
/usr/include/opencv2/nonfree/features2d.hpp:83:55: error: expected ‘,’ or ‘...’ before ‘<’ token
void buildGaussianPyramid( const Mat& base, vector<Mat>& pyr, int nOctaves
^
/usr/include/opencv2/nonfree/features2d.hpp:84:33: error: ‘vector’ does not name a type
void buildDoGPyramid( const vector<Mat>& pyr, vector<Mat>& dogpyr ) const;
^
/usr/include/opencv2/nonfree/features2d.hpp:84:39: error: expected ‘,’ or ‘...’ before ‘<’ token
void buildDoGPyramid( const vector<Mat>& pyr, vector<Mat>& dogpyr ) const;
^
/usr/include/opencv2/nonfree/features2d.hpp:85:39: error: ‘vector’ does not name a type
void findScaleSpaceExtrema( const vector<Mat>& gauss_pyr, const vector<Mat>
^
/usr/include/opencv2/nonfree/features2d.hpp:85:45: error: expected ‘,’ or ‘...’ before ‘<’ token
void findScaleSpaceExtrema( const vector<Mat>& gauss_pyr, const vector<Mat>
^
/usr/include/opencv2/nonfree/features2d.hpp:89:40: error: ‘vector’ has not been declared
void detectImpl( const Mat& image, vector<KeyPoint>& keypoints, const Mat&
^
/usr/include/opencv2/nonfree/features2d.hpp:89:46: error: expected ‘,’ or ‘...’ before ‘<’ token
void detectImpl( const Mat& image, vector<KeyPoint>& keypoints, const Mat&
^
/usr/include/opencv2/nonfree/features2d.hpp:90:41: error: ‘vector’ has not been declared
void computeImpl( const Mat& image, vector<KeyPoint>& keypoints, Mat& descr
^
/usr/include/opencv2/nonfree/features2d.hpp:90:47: error: expected ‘,’ or ‘...’ before ‘<’ token
void computeImpl( const Mat& image, vector<KeyPoint>& keypoints, Mat& descr
^
/usr/include/opencv2/nonfree/features2d.hpp:125:28: error: ‘vector’ has not been declared
CV_OUT vector<KeyPoint>& keypoints) const;
^
/usr/include/opencv2/nonfree/features2d.hpp:125:34: error: expected ‘,’ or ‘...’ before ‘<’ token
CV_OUT vector<KeyPoint>& keypoints) const;
^
In file included from /usr/include/opencv2/nonfree/nonfree.hpp:46:0,
from /home/huruiqi/SLAM/orbbec/SLAM/feature_tester/test_on_image/TestOnImage/feature_tester.cpp:8:
/usr/include/opencv2/nonfree/features2d.hpp:128:28: error: ‘vector’ has not been declared
CV_OUT vector<KeyPoint>& keypoints,
^
/usr/include/opencv2/nonfree/features2d.hpp:128:34: error: expected ‘,’ or ‘...’ before ‘<’ token
CV_OUT vector<KeyPoint>& keypoints,
^
/usr/include/opencv2/nonfree/features2d.hpp:127:10: error: ‘void cv::SURF::operator()(cv::InputArray, cv::InputArray, int) const’ cannot be overloaded
void operator()(InputArray img, InputArray mask,
^
In file included from /usr/include/opencv2/nonfree/nonfree.hpp:46:0,
from /home/huruiqi/SLAM/orbbec/SLAM/feature_tester/test_on_image/TestOnImage/feature_tester.cpp:8:
/usr/include/opencv2/nonfree/features2d.hpp:124:10: error: with ‘void cv::SURF::operator()(cv::InputArray, cv::InputArray, int) const’
void operator()(InputArray img, InputArray mask,
^
In file included from /usr/include/opencv2/nonfree/nonfree.hpp:46:0,
from /home/huruiqi/SLAM/orbbec/SLAM/feature_tester/test_on_image/TestOnImage/feature_tester.cpp:8:
/usr/include/opencv2/nonfree/features2d.hpp:132:5: error: ‘AlgorithmInfo’ does not name a type
AlgorithmInfo* info() const;
^
/usr/include/opencv2/nonfree/features2d.hpp:142:40: error: ‘vector’ has not been declared
void detectImpl( const Mat& image, vector<KeyPoint>& keypoints, const Mat&
^
/usr/include/opencv2/nonfree/features2d.hpp:142:46: error: expected ‘,’ or ‘...’ before ‘<’ token
void detectImpl( const Mat& image, vector<KeyPoint>& keypoints, const Mat&
^
/usr/include/opencv2/nonfree/features2d.hpp:143:41: error: ‘vector’ has not been declared
void computeImpl( const Mat& image, vector<KeyPoint>& keypoints, Mat& descr
^
/usr/include/opencv2/nonfree/features2d.hpp:143:47: error: expected ‘,’ or ‘...’ before ‘<’ token
void computeImpl( const Mat& image, vector<KeyPoint>& keypoints, Mat& descr
然后，根据路径/usr/include/opencv2/nonfree/features2d.hpp找到这个文件，首先
sudo chmod 777 features2d.cpp
然后打开，加上以下内容：
#include 在namespace cv里加上声明：
class AlgorithmInfo;
保存，终于可以用SIFT了！！
原图：
SIFT角点：
