A Study on Food Value Estimation From Images: Taxonomies, Datasets, and Techniques

Monitoring nutritional values in food can help an individual in planning a healthy diet. In addition, regular dietary assessment can improve and maintain the physical and mental health of individuals. Recent advancement in computer vision using Deep Learning has enabled researchers to develop various techniques for automatic food nutrition estimation frameworks. Researchers have also contributed to prepare large food image datasets consisting of various food classes for this purpose. However, automatic estimation of nutritional values from food images still remains a challenging task. This review paper critically analyzes and summarizes existing methodologies and datasets used for automated estimation of nutritional value from food images. We first define the taxonomies in order to categorize the existing research works. Then, we study different methods to detect the food value estimation from food images in those categories. We have critically analyzed existing methods and compared the performance of various approaches for estimating food value using conventional performance metrics such as Accuracy, Error Rate, Intersection over Union (IoU), Sensitivity, Specificity, Precision, etc. In particular, we emphasize the current trends and techniques of Deep Learning-based approaches for food value estimation from images. Moreover, we have identified the ongoing challenges associated with automated food estimation systems and outlined the potential future directions. This review can immensely benefit researchers and practitioners, including computer scientists, health practitioners, and nutritionists.