How do I into md5?

Question: how exactly are 4chan's pictures hashed?

I figured it's md5 since in clearly says so in the motherfucking tag, but if I try to actually hash a picture with md5 I always get a different code.
Now, I admit it, I don't know shit about hashing.

So then I tried comparing the results to see some pattern
what 4chan had: 4XgNLCurJpsOWCRH/Vlicg==
what I got: e1780d2c2bab269b0e582447fd596272

It looks like 4chan does some additional shit to the hash string, but I have no clues as to what exactly it does.
Hell, it's 22 characters against 32. How the fuck am I even supposed to deal with that.

So... help? I'm out of ideas to be honest.

>>13
How feasible would it be to make a valid image that would collide with a specific hash?

And what would the purpose be?  So that you could not post an image that is different to the first!