Update README.md

Author: shimat

README.md

@@ -1,6 +1,6 @@
 ![opencvsharp](https://socialify.git.ci/shimat/opencvsharp/image?description=1&forks=1&language=1&owner=1&pattern=Plus&stargazers=1&theme=Light)
 
-[![Github Actions Windows Status](https://github.com/shimat/opencvsharp/workflows/Windows%20Server%202022/badge.svg)](https://github.com/shimat/opencvsharp/actions)  [![Github Actions Ubuntu Status](https://github.com/shimat/opencvsharp/workflows/Ubuntu%2018.04/badge.svg)](https://github.com/shimat/opencvsharp/actions) [![Github Actions MacOS Status](https://github.com/shimat/opencvsharp/workflows/macOS%2010.15/badge.svg)](https://github.com/shimat/opencvsharp/actions) [![GitHub license](https://img.shields.io/github/license/shimat/opencvsharp.svg)](https://github.com/shimat/opencvsharp/blob/master/LICENSE) 
+[![Github Actions Windows Status](https://github.com/shimat/opencvsharp/workflows/Windows%20Server%202022/badge.svg)](https://github.com/shimat/opencvsharp/actions)  [![Github Actions Ubuntu Status](https://github.com/shimat/opencvsharp/workflows/Ubuntu%2020.04/badge.svg)](https://github.com/shimat/opencvsharp/actions) [![Github Actions MacOS Status](https://github.com/shimat/opencvsharp/workflows/macOS%2010.15/badge.svg)](https://github.com/shimat/opencvsharp/actions) [![GitHub license](https://img.shields.io/github/license/shimat/opencvsharp.svg)](https://github.com/shimat/opencvsharp/blob/master/LICENSE) 
 
 Old versions of OpenCvSharp are stored in [opencvsharp_2410](https://github.com/shimat/opencvsharp_2410).
 
@@ -19,19 +19,18 @@ Old versions of OpenCvSharp are stored in [opencvsharp_2410](https://github.com/
 |---------|-------------|------|
 |**OpenCvSharp4.runtime.win**| Native bindings for Windows x64/x86 (except UWP) | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4.runtime.win.svg)](https://badge.fury.io/nu/OpenCvSharp4.runtime.win) |
 |**OpenCvSharp4.runtime.uwp**| Native bindings for UWP (Universal Windows Platform) x64/x86/ARM | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4.runtime.uwp.svg)](https://badge.fury.io/nu/OpenCvSharp4.runtime.uwp) |
-|**OpenCvSharp4.runtime.ubuntu.18.04-x64**| Native bindings for Ubuntu 18.04 x64 | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4.runtime.ubuntu.18.04-x64.svg)](https://badge.fury.io/nu/OpenCvSharp4.runtime.ubuntu.18.04-x64) |
+|**OpenCvSharp4.runtime.ubuntu.20.04-x64**| Native bindings for Ubuntu 20.04 x64 | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4_.runtime.ubuntu.20.04-x64.svg)](https://badge.fury.io/nu/OpenCvSharp4_.runtime.ubuntu.20.04-x64) |
 |**OpenCvSharp4.runtime.osx.10.15-x64**| Native bindings for macOS 10.15 x64 | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4.runtime.osx.10.15-x64.svg)](https://www.nuget.org/packages/OpenCvSharp4.runtime.osx.10.15-x64/) |
 |**OpenCvSharp4.runtime.linux-arm**| Native bindings for Linux Arm | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4.runtime.linux-arm.svg)](https://www.nuget.org/packages/OpenCvSharp4.runtime.linux-arm/) |
 |**OpenCvSharp4.runtime.wasm**| Native bindings for WebAssembly | [![NuGet version](https://badge.fury.io/nu/OpenCvSharp4.runtime.wasm.svg)](https://www.nuget.org/packages/OpenCvSharp4.runtime.wasm/) |
 
-Native binding (OpenCvSharpExtern.dll / libOpenCvSharpExtern.so) is required to work OpenCvSharp. To use OpenCvSharp, you should add both `OpenCvSharp4` and `OpenCvSharp4.runtime.*` packages to your project. Currently, native bindings for Windows, UWP, Ubuntu 18.04 and macOS are released.
+Native binding (OpenCvSharpExtern.dll / libOpenCvSharpExtern.so) is required to work OpenCvSharp. To use OpenCvSharp, you should add both `OpenCvSharp4` and `OpenCvSharp4.runtime.*` packages to your project. Currently, native bindings for Windows, UWP, Ubuntu and macOS are released.
 
 Packages named OpenCvSharp3-* and OpenCvSharp-* are deprecated.
 > [OpenCvSharp3-AnyCPU](https://www.nuget.org/packages/OpenCvSharp3-AnyCPU/) / [OpenCvSharp3-WithoutDll](https://www.nuget.org/packages/OpenCvSharp3-WithoutDll/) / [OpenCvSharp-AnyCPU](https://www.nuget.org/packages/OpenCvSharp-AnyCPU/) /  [OpenCvSharp-WithoutDll](https://www.nuget.org/packages/OpenCvSharp-WithoutDll/)
 
 ## Docker images
-https://hub.docker.com/u/shimat
-- Ubuntu 18.04 (.NET Core 3.1): [shimat/ubuntu18-dotnetcore3.1-opencv4.5.0](https://hub.docker.com/r/shimat/ubuntu18-dotnetcore3.1-opencv4.5.0)
+- [Ubuntu](https://github.com/shimat?tab=packages)
 - For Google App Engine Flexible (.NET Core 3.1): [shimat/appengine-aspnetcore3.1-opencv4.5.0](https://hub.docker.com/r/shimat/appengine-aspnetcore3.1-opencv4.5.0)
 - For AWS Lambda (.NET 5): [shimat/al2-dotnet5-opencv4.5.0](https://hub.docker.com/r/shimat/al2-dotnet5-opencv4.5.0)
   - Code sample: https://github.com/shimat/opencvsharp_AWSLambdaSample
@@ -44,42 +43,26 @@ Add `OpenCvSharp4` and `OpenCvSharp4.runtime.win` NuGet packages to your project
 ### UWP
 Add `OpenCvSharp4` and `OpenCvSharp4.runtime.uwp` NuGet packages to your project. Note that `OpenCvSharp4.runtime.win` and `OpenCvSharp4.Windows` don't work for UWP. 
 
-### Ubuntu 18.04
-Add `OpenCvSharp4` and `OpenCvSharp4.runtime.ubuntu.18.04.x64` NuGet packages to your project.
+### Ubuntu 20.04
+Add `OpenCvSharp4` and `OpenCvSharp4.runtime.ubuntu.20.04.x64` NuGet packages to your project.
 ```
 dotnet new console -n ConsoleApp01
 cd ConsoleApp01
 dotnet add package OpenCvSharp4
-dotnet add package OpenCvSharp4.runtime.ubuntu.18.04-x64
+dotnet add package OpenCvSharp4.runtime.ubuntu.20.04-x64
 # -- edit Program.cs --- # 
 dotnet run
 ```
 
-### Google AppEngine Flexible (Ubuntu 16.04)
-Some Docker images are provided to use OpenCvSharp with AppEngine Flexible. The native binding (libOpenCvSharpExtern) is already built in the docker image and you don't need to worry about it.
-```
-FROM shimat/appengine-aspnetcore3.1-opencv4.5.0:20201030
-
-ADD ./ /app 
-ENV ASPNETCORE_URLS=http://*:${PORT} 
-
-WORKDIR /app 
-ENTRYPOINT [ "dotnet", "YourAspNetCoreProject.dll" ]
-```
-
-### Ubuntu 18.04 Docker image
-You can use the `shimat/ubuntu18-dotnetcore3.1-opencv4.5.0` docker image.
-This issue may be helpful: https://github.com/shimat/opencvsharp/issues/920
-
 ### Downloads
 If you do not use NuGet, get DLL files from the [release page](https://github.com/shimat/opencvsharp/releases).
 
 ## Target OpenCV
 * [OpenCV 4.5.](http://opencv.org/) with [opencv_contrib](https://github.com/opencv/opencv_contrib)
 
 ## Requirements
-* [.NET Framework 4.6.1](http://www.microsoft.com/ja-jp/download/details.aspx?id=1639) / [.NET Core 2.0](https://www.microsoft.com/net/download) / [Mono](http://www.mono-project.com/Main_Page)
-* (Windows) [Visual C++ 2019 Redistributable Package](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads)
+* [.NET Framework 4.8](http://www.microsoft.com/ja-jp/download/details.aspx?id=1639) / [.NET Core 2.0](https://www.microsoft.com/net/download) / [Mono](http://www.mono-project.com/Main_Page)
+* (Windows) [Visual C++ 2022 Redistributable Package](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads)
 * (Windows Server) Media Foundation
 ```
 PS1> Install-WindowsFeature Server-Media-Foundation
@@ -175,10 +158,10 @@ If you want to use some OpenCV features that are not provided by default in Open
 - Edit `build_windows.ps1` or `build_uwp.ps1` to customize the CMake parameters .
 - Run the PowerShell script.
 
-### Ubuntu 18.04
+### Ubuntu
 - Build OpenCV with opencv_contrib. 
   - https://www.learnopencv.com/install-opencv-4-on-ubuntu-18-04/
-- Install .NET Core SDK. https://docs.microsoft.com/ja-jp/dotnet/core/install/linux-package-manager-ubuntu-1804
+- Install .NET Core SDK. https://learn.microsoft.com/ja-jp/dotnet/core/install/linux-ubuntu
 - Get OpenCvSharp source files
 ```
 git clone https://github.com/shimat/opencvsharp.git