For anyone keen to learn more about object detection (and deep learning in general), I just finished working through an excellent free MOOC taught by Jeremy Howard (former chief scientist at Kaggle) - you basically learn how to fine-tune a convolutional neural network with your own data (e.g. hotdog vs not hotdog) in lesson 2!
I can't recommend that course enough! I attended it in person and got a lot out of it. Jeremy & Rachel were also enormously kind & helpful outside of class.
http://course.fast.ai/lessons/lesson2.html