To use the super resolution model in ImageTrans, download the zip and extract to the superresolution folder of the app.
Download link: https://github.com/xinntao/Real-ESRGAN/releases/tag/v0.2.5.0
You may need to run the following for mac and Linux to add execution permission:
mac:
chmod +x /Applications/ImageTrans.app/Contents/Resources/ImageTrans/superresolution/realesrgan-ncnn-vulkan Linux:
chmod +x realesrgan-ncnn-vulkan