Android : Round shaped image is elongated horizontally or vertically

I have to display a splash image which has a round shaped object (a Ball). The Layout for splash is a simple linear layout with just a single Image view to occupy the full screen.

Image : single image with the size of 1280 x 720.

When my splash screen is shown in the App, The round object is shown in different shape in different screen sizes. I hope the aspect ratio and the resolution is the cause for these elongated images.

Could you please suggest an idea / approach to solve this ? Do I need to consider the aspect ratio or the resolution or both ?

Finally the ball should look like a ball in all the devices :)

Thanks in Advance.