opencv获得图像某点像素值等

http://docs.opencv.org/2.4/doc/user_guide/ug_mat.html

cv::Mat 获取数据的下标和值

float intensity1 = frame.at<uchar>(pFaceInfo.iEyeLY, pFaceInfo.iEyeLX);
	float intensity2 = frame.at<uchar>(pFaceInfo.iEyeRY, pFaceInfo.iEyeRX);
	float intensity3 = frame.at<uchar>(pFaceInfo.iNoseY, pFaceInfo.iNoseX);

Scalar intensity = img.at<uchar>( row_n,  col_n );