Put rectangle and text into video

• OpenCvSharp
• C# Winform

Environment

Please import these dll into project using Solution Explorer > Refrences > Add.
- OpenCvSharp.dll
- OpenCvSharp.Blob.dll
- OpenCvSharp.Extensions.dll

Pleaese copy these dll into bin folder of project.
- opencv_videoio_ffmpeg440_64.dll
- OpenCvSharpExtern.dll