Shelfie is a startup venture that aims to crowd source out-of-stock in stores. Using an app, the user can take pictures of empty shelves. The mobile application then extracts the bar code from the image, determines if the shelf is indeed empty, and notifies subscribed stores. In turn, the user gets points that he or she can later use to collect rewards. Shelfie was co-founded by Puerto Rican entrepreneurs Edward Betancourt and CJ Acosta. My team was hired as independent contractors to develop the image processing tools to extract barcode information from the empty shelf images. Additionally, we implemented a fallback mechanism that used Amazon’s Mechanical Turk to obtain product information from images that were too distorted to obtain barcode information.