图像特征关键点及关键点匹配绘制函数

http://www.opencv.org.cn/opencvdoc/2.3.2/html/modules/features2d/doc/drawing_function_of_keypoints_and_matches.html#id1

drawMatches

给定两幅图像，绘制寻找到的特征关键点及其匹配.

C++: void drawMatches(const Mat& img1, const vector<KeyPoint>& keypoints1, const Mat& img2, const vector<KeyPoint>& keypoints2, const vector<DMatch>& matches1to2, Mat& outImg, const Scalar& matchColor=Scalar::all(-1), const Scalar& singlePointColor=Scalar::all(-1), const vector<char>& matchesMask=vector<char>(), int flags=DrawMatchesFlags::DEFAULT )

C++: void drawMatches(const Mat& img1, const vector<KeyPoint>& keypoints1, const Mat& img2, const vector<KeyPoint>& keypoints2, const vector<vector<DMatch>>& matches1to2, Mat& outImg, const Scalar& matchColor=Scalar::all(-1), const Scalar& singlePointColor=Scalar::all(-1), const vector<vector<char>>& matchesMask=vector<vector<char> >(), int flags=DrawMatchesFlags::DEFAULT )

Parameters: img1 – First source image.keypoints1 – Keypoints from the first source image.img2 – Second source image.keypoints2 – Keypoints from the second source image.matches – Matches from the first image to the second one, which means that keypoints1[i] has a corresponding point in keypoints2[matches[i]] .outImg – Output image. Its content depends on the flags value defining what is drawn in the output image. See possible flags bit values below.matchColor – Color of matches (lines and connected keypoints). If matchColor==Scalar::all(-1) , the color is generated randomly.singlePointColor – Color of single keypoints (circles), which means that keypoints do not have the matches. If singlePointColor==Scalar::all(-1) , the color is generated randomly.matchesMask – Mask determining which matches are drawn. If the mask is empty, all matches are drawn.flags – Flags setting drawing features. Possible flags bit values are defined by DrawMatchesFlags.

This function draws matches of keypoints from two images in the output image. Match is a line connecting two keypoints (circles). The structure DrawMatchesFlags is defined as follows:

struct DrawMatchesFlags { enum { DEFAULT = 0, // Output image matrix will be created (Mat::create), // i.e. existing memory of output image may be reused. // Two source images, matches, and single keypoints // will be drawn. // For each keypoint, only the center point will be // drawn (without a circle around the keypoint with the // keypoint size and orientation). DRAW_OVER_OUTIMG = 1, // Output image matrix will not be // created (using Mat::create). Matches will be drawn // on existing content of output image. NOT_DRAW_SINGLE_POINTS = 2, // Single keypoints will not be drawn. DRAW_RICH_KEYPOINTS = 4 // For each keypoint, the circle around // keypoint with keypoint size and orientation will // be drawn. }; };

drawKeypoints

绘制特征关键点.

C++: void drawKeypoints(const Mat& image, const vector<KeyPoint>& keypoints, Mat& outImg, const Scalar& color=Scalar::all(-1), int flags=DrawMatchesFlags::DEFAULT )

Parameters: image – Source image.keypoints – Keypoints from the source image.outImg – Output image. Its content depends on the flags value defining what is drawn in the output image. See possible flags bit values below.color – Color of keypoints.flags – Flags setting drawing features. Possible flags bit values are defined by DrawMatchesFlags. See details above in drawMatches() .