Abstract
Purpose: establish an objective and quantitative fecal aesthetics evaluation system, converting traditional subjective aesthetics into a computable and reproducible mathematical model. Methods: Based on fecal science, color science,ological measurement, and chemical sensing technology, a fecal aesthetics evaluation framework was constructed, including color, shape, and odor dimensions. The color dimension was based on the CIE Lab color space, defining an ideal "earthenware color" vector, and the CIE2000 color difference formula was used to calculate similarity. shape dimension introduced the Bristol stool classification method (BSFS), combined with contour curvature analysis, convex hull ratio calculation, and surface texture feature extraction, to quantify smoothness, firmness and anti-stickiness. The odor dimension used an electronic nose sensor array to establish a normalized odor intensity model. The weights of each dimension were determined by the analytic hierarchy process and the Fecal Aesthetics Index (FAI) was constructed. Results: The mathematical expressions of each dimension were successfully defined, a complete parameter calibration method was given, and feasibility of the model was verified through a simulation case. Conclusion: This model provides a theoretical framework and engineering implementation path for the objective aesthetics evaluation of feces, and has potential value in health monitoring, dietary assessment, and other fields.