Donation of photos for digital archive

Recently, our library has been given a collection of photographs that were previously on display in a local business location. These are photos of the customers of the business, many are children. These photos span several decades and are important to many. 

We would like to digitize these photos and make them available via the internet because we believe these to be of sentimental, cultural, historical and academic value to our region and beyond.

The photos were given to our library by the business that had previously displayed them and also produced the photos. What are the issues of rights and permissions raised by making these images freely available online, especially given that many of those in the photos are children? Thanks for your help.