opencv学习笔记4：用.at访问图像像素时报错

问题描述：

opencv用.at访问图像像素时报错

OpenCV Error: Assertion failed (((((sizeof(size_t)<<28)|0x8442211) >> ((DataType<_Tp>::depth) & ((1 << 3) - 1))*4) & 15) == elemSize1()) in cv::Mat::at, file d:\opencv\opencv3.1.0\opencv\build\include\opencv2\core\mat.inl.hpp, line 919

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原因分析：

image.at<数据类型>（row,col）中的“数据类型”写错了，一定要清楚自己要访问的图像的数据类型

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解决方案：

以下是Mat类型与数据类型对应关系：

Unsigned 8bits uchar 0~255
Mat: CV_8UC1, CV_8UC2, CV_8UC3, CV_8UC4

Signed 8bits char -128~127
Mat: CV_8SC1，CV_8SC2，CV_8SC3，CV_8SC4

Unsigned 16bits ushort 0~65535
Mat: CV_16UC1，CV_16UC2，CV_16UC3，CV_16UC4

Signed 16bits short -32768~32767
Mat: CV_16SC1，CV_16SC2，CV_16SC3，CV_16SC4

Signed 32bits int -2147483648~2147483647
Mat: CV_32SC1，CV_32SC2，CV_32SC3，CV_32SC4

Float 32bits float -1.1810-38~3.4010-38
Mat: CV_32FC1，CV_32FC2，CV_32FC3，CV_32FC4

Double 64bits double
Mat: CV_64FC1，CV_64FC2，CV_64FC3，CV_64FC4

下面是如何查看图像的Mat类型：
cout<