Raspberry Pi Official 7" Touch Screen - Images Stretched Lengthwise & Solution

[clintiepoo]

Background

To start with, the Raspberry Pi Touch Display isn't the best picture frame - the colors aren't great. But it's what I have on my desk. I have previously used Magic Mirror and MMM-BackgroundSlideshow to achieve a similar result. I thought I'd try picframe. I just wanted to share what my problem was and how I fixed it.

The problem: the pixels aren't square

Resolution of the screen is 800×480 (25:15 or 1.6667)
Size of the screen: 154.08 mm x 85.92 mm (about 27:15 or 1.7933)
Difference: 7.5% or 2:15 stretched lengthwise. this is noticeable

Several articles discuss this. For example: circles look like eggs!!!

The fix

I manually checked with a ruler and iterated until I got the correct ratio. Edit ~/.local/lib/python3.9/site-packages/picframe/viewer_display.py

Change this line

wh_rat = (self.__display.width * self.__sfg.iy) / (self.__display.height * self.__sfg.ix)

to this

wh_rat = ((self.__display.width+60) * self.__sfg.iy) / (self.__display.height * self.__sfg.ix)

What won't work

For some reason, picframe doesn't respect the screen size manually set in /boot/config.txt

framebuffer_width=800
framebuffer_height=444
framebuffer_aspect=-1