Quality of Parallax Top-B Image

Hello,How can in Travel Template I improve the quality of the parallax top-b image? It looks too grainy and in mobile version it is only half shown.

Thanks

The quality of the images has nothing to do with the template or the modules. You just have to upload pictures with more pixels. You can set the aspect ratio in the slider (e.g. 16:9).

Apple IOS is not supporting the "cover" css modus, therefore the picture looks bad.
Maybe setup the background picture not to cover in section theme config.
There is no other solution for this

Thank you.
What size's image do you recommend me to use?

The original picture of the TP Travel-Quickstart is:

1280 x 447 Px and 154 KB