OpenCV 中 GrabCut 的可运行代码
参考:http://www.cnblogs.com/tornadomeet/archive/2012/11/09/2763271.html
真的很佩服这个算法!
- #include "opencv2/highgui/highgui.hpp"#include "opencv2/imgproc/imgproc.hpp"#include < iostream > using namespace std;
- using namespace cv;
- static void help() {
- cout << "\nThis program demonstrates GrabCut segmentation -- select an object in a region\n""and then grabcut will attempt to segment it out.\n""Call:\n""./grabcut <image_name>\n""\nSelect a rectangular area around the object you want to segment\n" << "\nHot keys: \n""\tESC - quit the program\n""\tr - restore the original image\n""\tn - next iteration\n""\n""\tleft mouse button - set rectangle\n""\n""\tCTRL+left mouse button - set GC_BGD pixels\n""\tSHIFT+left mouse button - set CG_FGD pixels\n""\n""\tCTRL+right mouse button - set GC_PR_BGD pixels\n""\tSHIFT+right mouse button - set CG_PR_FGD pixels\n" << endl;
- }
- const Scalar RED = Scalar(0, 0, 255);
- const Scalar PINK = Scalar(230, 130, 255);
- const Scalar BLUE = Scalar(255, 0, 0);
- const Scalar LIGHTBLUE = Scalar(255, 255, 160);
- const Scalar GREEN = Scalar(0, 255, 0);
- const int BGD_KEY = CV_EVENT_FLAG_CTRLKEY; //Ctrl键
- const int FGD_KEY = CV_EVENT_FLAG_SHIFTKEY; //Shift键
- static void getBinMask(const Mat & comMask, Mat & binMask) {
- if (comMask.empty() || comMask.type() != CV_8UC1) CV_Error(CV_StsBadArg, "comMask is empty or has incorrect type (not CV_8UC1)");
- if (binMask.empty() || binMask.rows != comMask.rows || binMask.cols != comMask.cols) binMask.create(comMask.size(), CV_8UC1);
- binMask = comMask & 1; //得到mask的最低位,实际上是只保留确定的或者有可能的前景点当做mask
- }
- class GCApplication {
- public: enum {
- NOT_SET = 0,
- IN_PROCESS = 1,
- SET = 2
- };
- static const int radius = 2;
- static const int thickness = -1;
- void reset();
- void setImageAndWinName(const Mat & _image, const string & _winName);
- void showImage() const;
- void mouseClick(int event, int x, int y, int flags, void * param);
- int nextIter();
- int getIterCount() const {
- return iterCount;
- }
- private: void setRectInMask();
- void setLblsInMask(int flags, Point p, bool isPr);
- const string * winName;
- const Mat * image;
- Mat mask;
- Mat bgdModel,
- fgdModel;
- uchar rectState,
- lblsState,
- prLblsState;
- bool isInitialized;
- Rect rect;
- vector < Point > fgdPxls,
- bgdPxls,
- prFgdPxls,
- prBgdPxls;
- int iterCount;
- };
- /*给类的变量赋值*/
- void GCApplication: :reset() {
- if (!mask.empty()) mask.setTo(Scalar: :all(GC_BGD));
- bgdPxls.clear();
- fgdPxls.clear();
- prBgdPxls.clear();
- prFgdPxls.clear();
- isInitialized = false;
- rectState = NOT_SET; //NOT_SET == 0
- lblsState = NOT_SET;
- prLblsState = NOT_SET;
- iterCount = 0;
- }
- /*给类的成员变量赋值而已*/
- void GCApplication: :setImageAndWinName(const Mat & _image, const string & _winName) {
- if (_image.empty() || _winName.empty()) return;
- image = &_image;
- winName = &_winName;
- mask.create(image - >size(), CV_8UC1);
- reset();
- }
- /*显示4个点,一个矩形和图像内容,因为后面的步骤很多地方都要用到这个函数,所以单独拿出来*/
- void GCApplication: :showImage() const {
- if (image - >empty() || winName - >empty()) return;
- Mat res;
- Mat binMask;
- if (!isInitialized) image - >copyTo(res);
- else {
- getBinMask(mask, binMask);
- image - >copyTo(res, binMask); //按照最低位是0还是1来复制,只保留跟前景有关的图像,比如说可能的前景,可能的背景
- }
- vector < Point > ::const_iterator it;
- /*下面4句代码是将选中的4个点用不同的颜色显示出来*/
- for (it = bgdPxls.begin(); it != bgdPxls.end(); ++it) //迭代器可以看成是一个指针
- circle(res, *it, radius, BLUE, thickness);
- for (it = fgdPxls.begin(); it != fgdPxls.end(); ++it) //确定的前景用红色表示
- circle(res, *it, radius, RED, thickness);
- for (it = prBgdPxls.begin(); it != prBgdPxls.end(); ++it) circle(res, *it, radius, LIGHTBLUE, thickness);
- for (it = prFgdPxls.begin(); it != prFgdPxls.end(); ++it) circle(res, *it, radius, PINK, thickness);
- /*画矩形*/
- if (rectState == IN_PROCESS || rectState == SET) rectangle(res, Point(rect.x, rect.y), Point(rect.x + rect.width, rect.y + rect.height), GREEN, 2);
- imshow( * winName, res);
- }
- /*该步骤完成后,mask图像中rect内部是3,外面全是0*/
- void GCApplication: :setRectInMask() {
- assert(!mask.empty());
- mask.setTo(GC_BGD); //GC_BGD == 0
- rect.x = max(0, rect.x);
- rect.y = max(0, rect.y);
- rect.width = min(rect.width, image - >cols - rect.x);
- rect.height = min(rect.height, image - >rows - rect.y); (mask(rect)).setTo(Scalar(GC_PR_FGD)); //GC_PR_FGD == 3,矩形内部,为可能的前景点
- }
- void GCApplication: :setLblsInMask(int flags, Point p, bool isPr) {
- vector < Point > *bpxls,
- *fpxls;
- uchar bvalue,
- fvalue;
- if (!isPr) //确定的点
- {
- bpxls = &bgdPxls;
- fpxls = &fgdPxls;
- bvalue = GC_BGD; //0
- fvalue = GC_FGD; //1
- } else //概率点
- {
- bpxls = &prBgdPxls;
- fpxls = &prFgdPxls;
- bvalue = GC_PR_BGD; //2
- fvalue = GC_PR_FGD; //3
- }
- if (flags & BGD_KEY) {
- bpxls - >push_back(p);
- circle(mask, p, radius, bvalue, thickness); //该点处为2
- }
- if (flags & FGD_KEY) {
- fpxls - >push_back(p);
- circle(mask, p, radius, fvalue, thickness); //该点处为3
- }
- }
- /*鼠标响应函数,参数flags为CV_EVENT_FLAG的组合*/
- void GCApplication: :mouseClick(int event, int x, int y, int flags, void * ) {
- // TODO add bad args check
- switch (event) {
- case CV_EVENT_LBUTTONDOWN:
- // set rect or GC_BGD(GC_FGD) labels
- {
- bool isb = (flags & BGD_KEY) != 0,
- isf = (flags & FGD_KEY) != 0;
- if (rectState == NOT_SET && !isb && !isf) //只有左键按下时
- {
- rectState = IN_PROCESS; //表示正在画矩形
- rect = Rect(x, y, 1, 1);
- }
- if ((isb || isf) && rectState == SET) //按下了alt键或者shift键,且画好了矩形,表示正在画前景背景点
- lblsState = IN_PROCESS;
- }
- break;
- case CV_EVENT_RBUTTONDOWN:
- // set GC_PR_BGD(GC_PR_FGD) labels
- {
- bool isb = (flags & BGD_KEY) != 0,
- isf = (flags & FGD_KEY) != 0;
- if ((isb || isf) && rectState == SET) //正在画可能的前景背景点
- prLblsState = IN_PROCESS;
- }
- break;
- case CV_EVENT_LBUTTONUP:
- if (rectState == IN_PROCESS) {
- rect = Rect(Point(rect.x, rect.y), Point(x, y)); //矩形结束
- rectState = SET;
- setRectInMask();
- assert(bgdPxls.empty() && fgdPxls.empty() && prBgdPxls.empty() && prFgdPxls.empty());
- showImage();
- }
- if (lblsState == IN_PROCESS) //已画了前后景点
- {
- setLblsInMask(flags, Point(x, y), false); //画出前景点
- lblsState = SET;
- showImage();
- }
- break;
- case CV_EVENT_RBUTTONUP:
- if (prLblsState == IN_PROCESS) {
- setLblsInMask(flags, Point(x, y), true); //画出背景点
- prLblsState = SET;
- showImage();
- }
- break;
- case CV_EVENT_MOUSEMOVE:
- if (rectState == IN_PROCESS) {
- rect = Rect(Point(rect.x, rect.y), Point(x, y));
- assert(bgdPxls.empty() && fgdPxls.empty() && prBgdPxls.empty() && prFgdPxls.empty());
- showImage(); //不断的显示图片
- } else if (lblsState == IN_PROCESS) {
- setLblsInMask(flags, Point(x, y), false);
- showImage();
- } else if (prLblsState == IN_PROCESS) {
- setLblsInMask(flags, Point(x, y), true);
- showImage();
- }
- break;
- }
- }
- /*该函数进行grabcut算法,并且返回算法运行迭代的次数*/
- int GCApplication: :nextIter() {
- if (isInitialized)
- //使用grab算法进行一次迭代,参数2为mask,里面存的mask位是:矩形内部除掉那些可能是背景或者已经确定是背景后的所有的点,且mask同时也为输出
- //保存的是分割后的前景图像
- grabCut( * image, mask, rect, bgdModel, fgdModel, 1);
- else {
- if (rectState != SET) return iterCount;
- if (lblsState == SET || prLblsState == SET) grabCut( * image, mask, rect, bgdModel, fgdModel, 1, GC_INIT_WITH_MASK);
- else grabCut( * image, mask, rect, bgdModel, fgdModel, 1, GC_INIT_WITH_RECT);
- isInitialized = true;
- }
- iterCount++;
- bgdPxls.clear();
- fgdPxls.clear();
- prBgdPxls.clear();
- prFgdPxls.clear();
- return iterCount;
- }
- GCApplication gcapp;
- static void on_mouse(int event, int x, int y, int flags, void * param) {
- gcapp.mouseClick(event, x, y, flags, param);
- }
- int main(int argc, char * *argv) {
- string filename = "C:\\Users\\ycadai\\Desktop\\9.jpg";
- Mat image = imread(filename, 1);
- if (image.empty()) {
- cout << "\n Durn, couldn't read image filename " << filename << endl;
- return 1;
- }
- help();
- const string winName = "image";
- cvNamedWindow(winName.c_str(), CV_WINDOW_AUTOSIZE);
- cvSetMouseCallback(winName.c_str(), on_mouse, 0);
- gcapp.setImageAndWinName(image, winName);
- gcapp.showImage();
- for (;;) {
- int c = cvWaitKey(0);
- switch ((char) c) {
- case '\x1b':
- cout << "Exiting ..." << endl;
- goto exit_main;
- case 'r':
- cout << endl;
- gcapp.reset();
- gcapp.showImage();
- break;
- case 'n':
- int iterCount = gcapp.getIterCount();
- cout << "<" << iterCount << "... ";
- int newIterCount = gcapp.nextIter();
- if (newIterCount > iterCount) {
- gcapp.showImage();
- cout << iterCount << ">" << endl;
- } else cout << "rect must be determined>" << endl;
- break;
- }
- }
- exit_main: cvDestroyWindow(winName.c_str());
- return 0;
- }
运行结果:
A.
B.
C.
C 例中的分割效果之好、迭代次数之少很让我惊讶。
D.
来源: http://lib.csdn.net/article/opencv/41912