Department of Electrical & Computer Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Sensors (Basel). 2024 Sep 19;24(18):6058. doi: 10.3390/s24186058.
In dietary assessment using a single-view food image, an object of known size, such as a checkerboard, is often placed manually in the camera's view as a scale reference to estimate food volume. This traditional scale reference is inconvenient to use because of the manual placement requirement. Consequently, utensils, such as plates and bowls, have been suggested as alternative references. Although these references do not need a manual placement procedure, there is a unique challenge when a dining bowl is used as a reference. Unlike a dining plate, whose shallow shape does not usually block the view of the food, a dining bowl does obscure the food view, and its shape may not be fully observable from the single-view food image. As a result, significant errors may occur in food volume estimation due to the unknown shape of the bowl. To address this challenge, we present a novel method to premeasure both the size and shape of the empty bowl before it is used in a dietary assessment study. In our method, an image is taken with a labeled paper ruler adhered to the interior surface of the bowl, a mathematical model is developed to describe its shape and size, and then an optimization method is used to determine the bowl parameters based on the locations of observed ruler makers from the bowl image. Experimental studies were performed using both simulated and actual bowls to assess the reliability and accuracy of our bowl measurement method.
在使用单视图食物图像进行饮食评估时，通常会手动将已知大小的物体（如棋盘）放置在相机的视野中作为比例参考，以估计食物的体积。这种传统的比例参考不方便使用，因为需要手动放置。因此，已经提出了餐具（如盘子和碗）作为替代参考。虽然这些参考不需要手动放置程序，但当用餐碗作为参考时，会出现一个独特的挑战。与浅形状通常不会阻挡食物视野的餐盘不同，用餐碗会遮挡食物的视野，并且从单视图食物图像中可能无法完全观察到其形状。因此，由于碗的形状未知，食物体积的估计可能会出现重大误差。为了解决这个挑战，我们提出了一种新方法，可以在饮食评估研究中使用之前，预先测量空碗的大小和形状。在我们的方法中，将附有标签的纸尺贴在碗的内表面上拍摄图像，然后开发一个数学模型来描述其形状和大小，然后使用优化方法根据从碗图像中观察到的标尺标记的位置来确定碗的参数。使用模拟和实际碗进行了实验研究，以评估我们的碗测量方法的可靠性和准确性。
