I am just thinking how about if half X or Y size to half of screensize, it would not look as bad you think, because it is exact half of screen resolution. Example 960x270 or 480x540 with Droid4.

Or with smaller N900 screen you can half both X and Y to 400x240 and it would be still almost 150 dpi, what I have been noticed the limit to good enough picture quality from 40 cm away from screen.