Food intake estimation method using short-range depth camera

Abstract

Dietary assessment is a comprehensive evaluation of a person's food intake. It is very important to people in modern life, especially to the elders. In general, food intake measurement is performed by using a scale. However, it is inconvenient since the food is measured one-by-one before and after eating. In order to increase the convenience of food intake measurement, a short-range depth camera is used to estimate the food intake directly on the food tray. Two main problems are encountered to achieve the above goal. One is the influence of the material of the tray. The other is the pixel without depth values in the depth image. The volume is estimated firstly and then converted to the weight using the specific gravity function. The weight is then converted to the calories based on the food calorie database. For every food, its specific gravity function can be approximated using linear, quadratic, or cubic functions. In the experimental study, the lowest average error of food intake weight is 5.6 grams. It is about 7.5 percent. The results show that the proposed method can estimate the food intake weight effectively.