# A Review of Recent Advances and Challenges in Grocery Label Detection and Recognition
## 2 Technological Review
### Label-Based System  
Previously described solutions rely on an internet connection, which may not be possible. This problem can be overcome by using computer vision algorithms that recognise the detected label based on visual features or textual information. **Lookout--Assisted Vision**[17]  
An application released by Google with the purpose of helping visually impaired people explore their surroundings. The system enables six kinds of activities: image description, text reading, food package identification, page capture, currency identification and object information. The system has two ways to identify the food package: via a barcode scanner, and the front of a food package recognition. The user should put the product in front of the camera to use the food label reader; if the product is in the wrong position, the system will warn the user to move the product until the front of the item is clearly visible. By downloading the database, the recogniser can work offline, with the inconvenience of reducing free memory space. The main limitation of this application is that it only recognises the front side of the package. **Alexa Accessibility--Show and Tell on the Echo Show**[18]  
Amazon Echo Show is a smart display, similar to a laptop, which is integrated with the virtual assistant [PERSON] to help with daily tasks. Show and Tell is an accessible Alexa feature designed to identify grocery items using the Echo Show's camera. With the product in front of the camera, the user only has to ask \"What am I holding?\" to activate the functionality. When the product is not identified, [PERSON] tells the user to turn the item, to find further rich information. Additionally, the beep sound system guides the user in the correct placement of the product. It may also provide a brief description of the product, stored in a database. Since the Show and Tell feature is only available on the Echo Show, its usefulness is restricted to home usage. **OrCam MyEye**[19]  
In addition to identifying products from barcode recognition, it also identifies products by reading the text label. The system applied in product recognition is the same as in reading books and newspapers; it will not provide information beyond legible words. The user must point to the product/text that he wants to be recognised. Without visual information and guidance on product placement, the possibility of the system not recognizing the words greatly increases. **Wine Searcher**[20]  
As the name suggests, it is an app for the wine and spirit industry. The aim is to inform the user about the specifications of the wine (the grape variety, the regions it comes from and the producers), the critics' score and, especially, it offers a price comparison tool using a search engine in online mode. The identification of the product is achieved by scanning the label. The system functionality is limited to a category of products enabling a focused recognition, but preventing applicability to other areas. On the other hand, the application was designed for visual people, so there are no additional features to help users obtain a good-quality image. **Amazon GO**[21]  
A chain of automatic stores that uses thousands of CCTV cameras, computer vision and machine learning methods to analyse if the customer picks up or puts back an item on the shelf and identifies what the item is. Even with a sophisticated system, its results are not entirely reliable, requiring auxiliary systems such as Bluetooth and weight sensors on shelves. Technological advances have led to the appearance of products that try to respond to the needs of consumers and retailers. Nevertheless, existing limitations highlight the importance of additional research. Table 1 summarises the comparison of the aforementioned technologies.