Upscaling adds background to the image

[IMXEren]

I tried upscaling the image (IMAGE1, PNG), with all of the upscaling options (x4, x16) but it returns the upscaled image (IMAGE2) with a black background. IMAGE1 has transparent background. Also, tried with Real-ESRGAN vulcan (model realesr-animevideov3) which returns the image (IMAGE3) without the background. Is this expected or a bug?

IMAGE1

IMAGE2

IMAGE3

[Lucchetto]

Hi, unfortunately this is expected behaviour since models are trained on images without alpha channel. Maybe I should add a warning in-app

[IMXEren]

Okay, that'll be fine! Your app is great, keep up the hard work. Upscaling is just about a few clicks process because of you & your support (if there is any). You may close this issue. Thanks!