Hello, are you by any chance using a map zoom / camera zoom plugin?
Yes! I'm using Kadajah_ZoomTools.js for map zoom. When I use it together with your Post-Processing plugin, pictures on screen appear zoomed out/scaled down abnormally.
Through browser console I found that Spriteset_Map scale becomes 2,2 when zoomed, and your post-processing filters are attached to Spriteset_Map, which seems to cause the issue with pictures.
Is there any way to fix this compatibility issue?