Download:
https://marketplace.visualstudio.com/items?itemName=VisualCPPTeam.ImageWatch#qna
For Visual Studio 2017 "support":
1. Download the extension (ImageWatch.vsix) and open it using WinRAR
2. From inside the bundle, open "extension.vsixmanifest" (using Notepad/Visual Studio, or any XML editor)
3. Edit line number 11 to match: "<InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[15.0]" />"
4. Edit line number 15 to match: "<Dependency Id="Microsoft.VisualStudio.MPF.15.0" DisplayName="Visual Studio MPF 15.0" Version="[15.0]" />"
5. Save the file and update it in the archive (select Yes in WinRAR dialog)
6. Install the extension (it will complain that it might not be compatible, but it works)