This is an interesting project. actually this is my main area of expertise. I'm an owner of start-up company that design and manufacture embedded vision solutions. So let's get to the project:
It's important to know what is the hardware that the people counter algorithm is going to be implemented. i.e. do you have PCs or servers at the site where the cameras is installed.
normally for this type of applications an embedded vision hardware is used (one which uses processors other than Intel) which offers much high performance and lower power, rugged, secure, and lower cost than the Intel based.
I can offer you both solutions
solution 1: based on Microsoft Kinect Sensor + on-site PC or server. (I'm bidding for this)
--> I will give you software based on windows or linux as you need.
--> you will buy all the hardware. i offer the software only
--> i will offer it to you as one milestone post paid no down payment.
--> I offer you the solution with no source code. but you are free to copy as many as you need
Solution 2: based on high performance embedded vision solution. (this would be other project)
--> complete hardware plus software unit.
--> i offer you both hardware and software as one compact low cost and low power solution.
--> this unit can connect directly to on-site surveillance IP cameras.
--> secure so no hacking of any kind.
--> the unit is small size, low power, rugged
--> can connect to IPcam, NVR, DVR.
So let's chat and discuss all issues.