Yeah... the imgur link is actually embedded
in the ip.bitcointalk.org URLs...
Taking the link to the first image in the OP as an example: https ://ip.bitcointalk.org/?u=
https%3A%2F%2Fi.imgur.com%2FmBsrI4Z.jpg&t=607&c=1NdT52aa5A3yJw
Extract the embedded URL (the bolded section): https%3A%2F%2Fi.imgur.com%2FmBsrI4Z.jpg
Convert the 'encoded' symbols using the following:
%3A => :
%2F => /
=>
https://i.imgur.com/mBsrI4Z.jpg