校正 + 旋转校正 OpenCV （C++）

校正 + 旋转校正 OpenCV （C++）

详细见：https://blog.youkuaiyun.com/Aquamarine__/article/details/115756475

视觉检查见：https://blog.youkuaiyun.com/Aquamarine__/article/details/115757527

旋转校正：

vector<Rect> boundRect(contours.size());
vector<RotatedRect> box(contours.size());
Point2f rect[4];  //定义数组存放四个顶点
for (int i = 0; i < contours.size(); i++) {
	box[i] = minAreaRect(Mat(contours[i]));
	boundRect[i] = boundingRect(Mat(contours[i]));  //计算轮廓的最小外接矩形
	if (box[i].size.width < 100 || box[i].size.height < 100)//筛选
		continue;
	//画一个矩形
	rectangle(img_new, Point(boundRect[i].x, boundRect[i].y), Point(boundRect[i].x + boundRect[i].width, boundRect[i].y + boundRect[i].height), Scalar(0, 255, 0), 2, 8);
	circle(img_new, Point(box[i].center.x, box[i].center.y), 5, Scalar(0, 255, 0), -1, 8);
	box[i].points(rect);
	for (int j = 0; j < 4; j++) {
		line(img_new, rect[j], rect[(j + 1) % 4], Scalar(0, 0, 255), 2, 8);
	}
	float angle;
	angle = box[i].angle;
	char width[20], height[20];
	//利用仿射变换进行旋转  
	if (0 < abs(angle) && abs(angle) <= 45)
		angle = angle;//负数，顺时针旋转
	else if (45 < abs(angle) && abs(angle) < 90)
		angle = 90 - abs(angle);//正数，逆时针旋转
	Point2f center = box[i].center;  //定义旋转中心坐标
	double angle0 = angle;
	double scale = 1;
	Mat roateM = getRotationMatrix2D(center, angle0, scale);  //获得旋转矩阵,顺时针为负，逆时针为正
	warpAffine(img_new, img_new, roateM, img_new.size()); //仿射变换
	imshow("11", img_new);

校正：

Point2f srcTri[3];
Point2f dstTri[3];
//设置源图像和目标图像上的三组点以计算仿射变换
srcTri[0] = Point2f(0, 0);
srcTri[1] = Point2f(img_new.cols - 1, 0);
srcTri[2] = Point2f(0, img_new.rows - 1);
dstTri[0] = Point2f(img_new.cols*0.0, img_new.rows*0.33);
dstTri[1] = Point2f(img_new.cols*0.85, img_new.rows*0.25);
dstTri[2] = Point2f(img_new.cols*0.15, img_new.rows*0.7);
// 设置目标图像的大小和类型与源图像一致
Mat warp_dst = Mat::zeros(img_new.rows, img_new.cols, img_new.type());
//求得仿射变换
Mat warp_mat = getAffineTransform(srcTri, dstTri);
//对源图像应用上求得的仿射变换
warpAffine(img_new, warp_dst, warp_mat, warp_dst.size());

// 对图像扭曲后再旋转
// 计算绕图像中点顺时针旋转50度缩放因子为0.6的旋转矩阵
Point center = Point(warp_dst.cols / 2, warp_dst.rows / 2);
double angle = -50.0;
double scale = 0.6;
// 通过上面的旋转细节信息求得旋转矩阵
Mat rot_mat = getRotationMatrix2D(center, angle, scale);
// 旋转已扭曲图像
Mat warp_rotate_dst;
warpAffine(warp_dst, warp_rotate_dst, rot_mat, warp_dst.size());
// 显示结果
imshow("source_window", img_new);
imshow("warp_window", warp_dst);
imshow("warp_rotate_window", warp_rotate_dst);