Test and Development of a Low-Cost Solution for Automatic Inspection of PET Bottle Codification

Abstract

Quality of packaging is a key factor in consumer choice for a particular product. Besides the package appearance, legal requirements demand that certain information is presented to the consumer. The main goal of this work is to evaluate the technical feasibility of using a Raspberry Pi board as a platform for automatic quality inspection for the expiration date and batch information in polyethylene terephthalate (PET) bottles. The system consists in capturing digital images using a Raspberry Pi Camera, processing the image obtained and performing optical character recognition in order to determine if the coding is compliant. Two models of bottles were used, and 24 images of each were captured, 15 of which were examples of compliant bottles and 9 were defective. The tests were divided into two sequences of processing methods. The best sequence achieved 100% specificity, 91.7% accuracy for model A bottle and 83.3% for model B.