安装

mac

brew install opencv

For compilers to find openblas you may need to set:
export LDFLAGS="-L/usr/local/opt/openblas/lib"
export CPPFLAGS="-I/usr/local/opt/openblas/include"

For pkg-config to find openblas you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/openblas/lib/pkgconfig"

格式
注意：不需要加cv::的namespace前缀

CV_8UC1

颜色空间

RGB → YUV
目前从BGR到YUV420的颜色空间变化仅支持转换到420p的两种格式，不支持转换到420sp。

假设src是OpenCV默认的BGR三通道图像，和420p的转换如下

// BGR CV_8UC3 with 640x960 → I420 CV_8UC1 with 960x960

cvtColor(src, dest, COLOR_BGR2YUV_I420);

// BGR CV_8UC3 with 640x960 → YV12 CV_8UC1 with 960x960

cvtColor(src, dest, COLOR_BGR2YUV_YV12);

YUV → RGB
支持420p或者420sp转换到BGR。

假设src是OpenCV默认的BGR三通道图像，和420p的转换如下

// I420 CV_8UC1 with 960x960 → BGR CV_8UC3 with 640x960

cvtColor(src, dest, COLOR_YUV2BGR_I420);

// YV12 CV_8UC1 with 960x960 → BGR CV_8UC3 with 640x960

cvtColor(src, dest, COLOR_YUV2BGR_YV12);

假设src是YUV420的420sp图像数据，到BGR的转换如下。

// NV12 CV_8UC1 with 960x960 → BGR CV_8UC3 with 640x960

cvtColor(src, dest, COLOR_YUV2BGR_NV12);

// NV21 CV_8UC1 with 960x960 → BGR CV8UC3 with 640x960

cvtColor(src, dest, COLOR_YUV2BGR_NV21);

掩模
简单叠加

A在掩模C是白色的地方叠加到B

A.copyTo(B, C);