Pagesimages fails to find the good image in those examples :
https://en.wikipedia.org/w/index.php?title=Troy_McClure&action=info
https://en.wikipedia.org/w/index.php?title=Professor_Frink&action=info
https://en.wikipedia.org/w/index.php?title=Moe_Szyslak&action=info
Maybe a ratio configuration change will be enough ?
Width/height ratio :
File:Troymcclure.png : 0.53
File:Frink.png : 0.49
File:Moe_Szyslak.png : 0.55