1，简介
ROI，感兴趣区域（region of interest)，截取图像
2，获取方法
方法1：使用Rect
cv::Mat src=cv::imread("*.bmp");//读取原图
cv::Mat matROI = src(cv::Rect(100,200,50,100));//截取原图，矩形区域
方法2：使用Range
cv::Mat src=cv::imread("*.bmp");//读取原图
cv::Mat matROI = src(cv::Range(100,150),cv::Range(200,300));//截取原图，矩形区域
3，图像叠加
注：Mat类型中copyTo函数和clone函数和赋值操作符操作。
3.1.1，代码1(copyTo,类型+尺寸相同)
stringstream ss;
cv::Mat src = cv::imread("BK5.jpg");//3通道彩图
cv::Mat* srcPointer = &src;
cv::Mat srcROI = src(cv::Rect(src.rows / 2 - 100, src.cols / 2 - 100, 100, 100));
ss << "src.isContinuous=" << src.isContinuous() <<endl;
ss << "src.type=" << src.type() << endl;
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::Mat srvROI_End = cv::Mat(srcROI.rows, srcROI.cols, srcROI.type(), cv::Scalar(0));
srvROI_End.copyTo(srcROI);
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::imshow("srcROI", srcROI);
cv::imshow("src-Result", src);
qDebug() << ss.str().c_str();
指针版
stringstream ss;
cv::Mat src = cv::imread("BK5.jpg");//3通道彩图
cv::Mat srcROI = src(cv::Rect(src.rows / 2 - 100, src.cols / 2 - 100, 100, 100));
cv::Mat* srcROIPointer = &srcROI;
ss << "src.isContinuous=" << src.isContinuous() <<endl;
ss << "src.type=" << src.type() << endl;
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::Mat srcROI_End = cv::Mat(srcROIPointer->rows, srcROIPointer->cols, srcROIPointer->type(), cv::Scalar(0));
srcROI_End.copyTo(*srcROIPointer);
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::imshow("srcROI", *srcROIPointer);
cv::imshow("src-Result", src);
qDebug() << ss.str().c_str();
3.1.2，打印结果
src.isContinuous=1
src.type=16
srcROI - Memery Address:000000EF810FF980
srcROI - Memery Address:000000EF810FF980
3.1.3，图片显示结果
原图的ROI区域，图片被处理。
3.1.4，结论
类型/尺寸相同，copyTo时，ROI图元修改会生效到原图中。
3.2.1，代码2(copyTo,类型不同，尺寸相同)
stringstream ss;
cv::Mat src = cv::imread("BK5.jpg");//3通道彩图
cv::Mat* srcPointer = &src;
cv::Mat srcROI = src(cv::Rect(src.rows / 2 - 100, src.cols / 2 - 100, 100, 100));
ss << "src.isContinuous=" << src.isContinuous() <<endl;
ss << "src.type=" << src.type() << endl;
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::Mat srvROI_End = cv::Mat(srcROI.rows, srcROI.cols, CV_8UC1, cv::Scalar(0));
srvROI_End.copyTo(srcROI);
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::imshow("srcROI", srcROI);
cv::imshow("src-Result", src);
qDebug() << ss.str().c_str();
3.2.2，打印结果
src.isContinuous=1
src.type=16
srcROI - Memery Address:000000EF810FF980
srcROI - Memery Address:000000EF810FF980
3.2.3，图片显示结果
原图的ROI区域，无处理效果。
3.2.4，结论
类型不同，尺寸相同，copyTo时，ROI图元不会生效到原图中。
3.3.1，代码2(copyTo,类型不同，尺寸相同)
stringstream ss;
cv::Mat src = cv::imread("BK5.jpg");//3通道彩图
cv::Mat* srcPointer = &src;
cv::Mat srcROI = src(cv::Rect(src.rows / 2 - 100, src.cols / 2 - 100, 100, 100));
ss << "src.isContinuous=" << src.isContinuous() <<endl;
ss << "src.type=" << src.type() << endl;
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::Mat srvROI_End = cv::Mat(srcROI.rows+100, srcROI.cols+100, srcROI.type(), cv::Scalar(0));
srvROI_End.copyTo(srcROI);
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::imshow("srcROI", srcROI);
cv::imshow("src-Result", src);
qDebug() << ss.str().c_str();
3.3.2，打印结果
src.isContinuous=1
src.type=16
srcROI - Memery Address:000000FC6E10F8E0
srcROI - Memery Address:000000FC6E10F8E0
3.3.3，图片显示结果
原图的ROI区域，无处理效果。
3.3.4，结论
类型相同，尺寸不同，copyTo时，ROI图元不会生效到原图中。
3.4.1，代码2(clone,类型+尺寸相同)
stringstream ss;
cv::Mat src = cv::imread("BK5.jpg");//3通道彩图
cv::Mat* srcPointer = &src;
cv::Mat srcROI = src(cv::Rect(src.rows / 2 - 100, src.cols / 2 - 100, 100, 100));
ss << "src.isContinuous=" << src.isContinuous() <<endl;
ss << "src.type=" << src.type() << endl;
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::Mat srcROI_End = cv::Mat(srcROI.rows, srcROI.cols, srcROI.type(), cv::Scalar(0));
srcROI = srcROI_End.clone();
ss << "srcROI - Memery Address:" << &srcROI << endl;
cv::imshow("srcROI", srcROI);
cv::imshow("src-Result", src);
qDebug() << ss.str().c_str();
3.4.2，打印结果
src.isContinuous=1
src.type=16
srcROI - Memery Address:00000006268FF560
srcROI - Memery Address:00000006268FF560
3.4.3，图片显示结果
原图的ROI区域，无处理效果。
3.4.4，结论
clone时，ROI图元不会生效到原图中。
4，制作掩膜
4.1.1，代码1(copyTo,类型不同，尺寸相同)
绿色掩膜
stringstream ss;
cv::Mat src = cv::imread("BK5.jpg");//3通道彩图cv::Mat srcROI = src(cv::Rect(src.rows / 2 - 100, src.cols / 2 - 100, 100, 100));cv::Mat* srcROIPointer = &srcROI;ss << "src.isContinuous=" << src.isContinuous() << endl;ss << "src.type=" << src.type() << endl;ss << "srcROI - Memery Address:" << &srcROI << endl;cv::Mat srcROI_End = cv::Mat(srcROIPointer->rows, srcROIPointer->cols, srcROIPointer->type(), cv::Scalar(0, 255, 0));cv::Mat srcROI_Mask = cv::Mat(srcROIPointer->rows, srcROIPointer->cols, srcROIPointer->type(), cv::Scalar(0, 255, 0));srcROI_End.copyTo(*srcROIPointer, srcROI_Mask);ss << "srcROI - Memery Address:" << &srcROI << endl;cv::imshow("srcROI", *srcROIPointer);cv::imshow("src-Result", src);qDebug() << ss.str().c_str();
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