Development of a low-cost portable scale integrated into a smartphone case based on image processing force estimations

This paper presents the development and implementation of a low-cost, portable scale utilizing a smartphone and image  processing technology. The main objective of this research is to explore the potential of using a compliant mechanism, markers, and  image processing techniques to accurately determine the weight of an object. We designed a 3D printed platform fitted with a  webcam to capture images of white markers on a black surface. The Image Processing Toolbox on MATLAB was used to detect  two parameters, the number of white pixels and the centroid positions of the white pixels with respect to the centre of the image in  each marker. Calibration is carried out to convert these two parameters into weight, hence accurately estimating the weight of an  object placed on the platform.