Image cropping depends on screen resolution

I believe I found a fundamental design flaw in Libreoffice Impress 5.4.5.1. 
Cropped images get distorted when changing the screen resolution. The root 
cause is that the dpi value of the current monitor is applied to all images 
instead of reading the dpi value from the image meta data. Since the odp file 
format uses length units (e.g. cm) when defining image cropping, the crop 
values of all images need to be changed when changing the monitor resolution. 
In any case a tool for converting odp files is required.