I have too many pictures on my Iphone 4s

I have my iphone set to backup to my computer instead of the icloud. I have a lot of pictures and would like to remove them from my phone but I want to make sure I have them copied somewhere on my computer but I can't seem to find the file that they're being backed up into. I can't seem to figure out any other way of getting them onto my computer except through an itunes sync. I used to have an htc evo and it was easy because I could just bluetooth everything so an Iphone is really different. I just want to have a solid copy of my mobile pictures somewhere on my computer so that I can feel comfortable deleting the ones on my phone. I'm using a macbook pro, so instructions for that specific software would be really really helpful!

If you have time, select some pictures and email them to an email address. This is time consuming, but it will work.