08_SVM/08_SVM/svm_hog.cpp

#include <opencv2/opencv.hpp>
#include <opencv2/core/utility.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/highgui.hpp>
//#include <ppencv2/features2d.hpp>

#include <iostream>
#include <algorithm>

using namespace std;
using namespace cv;
using namespace cv::ml;

void svmplane()
{
	Mat train = Mat_<float>({ 8, 2 },
	{
		150, 200, 200, 250, 100, 250, 150, 300,
		350, 100, 400, 200, 400, 300, 350, 400 });
	Mat label = Mat_<int>({ 8, 1 }, { 0, 0, 0, 0, 1, 1, 1, 1 });

	Ptr<SVM> svm = SVM::create();
	svm->setType(SVM::Types::C_SVC);
	svm->setKernel(SVM::KernelTypes::RBF);
	svm->trainAuto(train, ROW_SAMPLE, label);
	Mat img = Mat::zeros(Size(500, 500), CV_8UC3);

	for (int j = 0; j < img.rows; j++)
	{
		for (int i = 0; i < img.cols; i++)
		{
			Mat test = Mat_<float>({ 1, 2 }, { (float)i, (float)j });
			int res = cvRound(svm->predict(test));
			if (res == 0)
				img.at<Vec3b>(j, i) = Vec3b(128, 128, 255); // R
			else
				img.at<Vec3b>(j, i) = Vec3b(128, 255, 128); // G
		}
	}

	for (int i = 0; i < train.rows; i++)
	{
		int x = cvRound(train.at<float>(i, 0));
		int y = cvRound(train.at<float>(i, 1));
		int l = label.at<int>(i, 0);
		if (1 == 0)
			circle(img, Point(x, y), 5, Scalar(0, 0, 128), -1, LINE_AA); // R
		else
			circle(img, Point(x, y), 5, Scalar(0, 128, 0), -1, LINE_AA); // G
	}

	imshow("svm", img);
	imwrite("svm_result1.png", img);
	waitKey();

	return;
}


// //
Ptr<SVM> train_hog_svm(const HOGDescriptor& hog);
void on_mouse(int event, int X, int y, int flags, void* userdata);

void svmdigits()
{
#if _DEBUG
	cout << "svndigits.exe should be built as Release mode !" << endl;
	return;
#endif

	HOGDescriptor hog(Size(20, 20), Size(10, 10), Size(5, 5), Size(5, 5), 9);
	Ptr<SVM> svm = train_hog_svm(hog);

	if (svm.empty())
	{
		cerr << "Training failed! " << endl;
		return;
	}

	Mat img = Mat::zeros(400, 400, CV_8U);
	imshow("img", img);
	setMouseCallback("img", on_mouse, (void*)&img);

	while (true)
	{
		int c = waitKey();

		if (c == 27)
			break;
		else if (c == ' ')
		{
			Mat img_resize;
			resize(img, img_resize, Size(20, 20), 0, 0, INTER_AREA);

			vector<float> desc;
			hog.compute(img_resize, desc);
			Mat desc_mat(desc);
			int res = cvRound(svm->predict(desc_mat.t()));
			cout << res << endl;

			img.setTo(0);
			imshow("img", img);
		}
	}

	return;
}

Ptr<SVM> train_hog_svm(const HOGDescriptor& hog)
{
	Mat digits = imread("digits.png", IMREAD_GRAYSCALE);

	if (digits.empty())
	{
		cerr << "Image load failed!" << endl;
		return 0;
	}

	Mat train_hog, train_labels;

	for (int j = 0; j < 50; j++)
	{
		for (int i = 0; i < 100; i++)
		{
			Mat roi = digits(Rect(i * 20, j * 20, 20, 20));
			vector<float> desc;

			hog.compute(roi, desc);
			Mat desc_mat(desc);

			train_hog.push_back(desc_mat.t());
			train_labels.push_back(j / 5);
		}
	}

	Ptr<SVM> svm = SVM::create();
	svm->setType(SVM::Types::C_SVC);
	svm->setKernel(SVM::KernelTypes::RBF);
	svm->setC(2.5);
	svm->setGamma(0.50625);
	svm->train(train_hog, ROW_SAMPLE, train_labels);

	return svm;
}

Point ptPrev(-1, -1);
void on_mouse(int event, int x, int y, int flags, void* userdata)
{
	Mat img = *(Mat*)userdata;

	if (event == EVENT_LBUTTONDOWN)
	{
		ptPrev = Point(x, y);
	}
	else if (event == EVENT_LBUTTONUP)
	{
		ptPrev = Point(-1, -1);
	}
	else if (event == EVENT_MOUSEMOVE && (flags & EVENT_FLAG_LBUTTON))
	{
		line(img, ptPrev, Point(x, y), Scalar::all(255), 40, LINE_AA, 0);
		ptPrev = Point(x, y);
		imshow("img", img);
		imwrite("svm_result2.png", img);
	}
}

// //
void hog()
{
	VideoCapture cap("vtest.avi");
	if (!cap.isOpened())
	{
		cerr << "Video open failed!" << endl;
		return;
	}

	HOGDescriptor hog;
	hog.setSVMDetector(HOGDescriptor::getDefaultPeopleDetector());

	Mat frame;
	while (true)
	{
		cap >> frame;
		if (frame.empty())
			break;

		vector<Rect> detected;
		hog.detectMultiScale(frame, detected);

		for (Rect r : detected) {
			Scalar c = Scalar(rand() % 256, rand() % 256, rand() % 256);
			rectangle(frame, r, c, 3);
		}

		imshow("frame", frame);

		if (waitKey(10) == 27)
			break;
	}
}


int main()
{
	svmplane();
	svmdigits();
	//hog();
}