Anthropometry measurements of farm workers using computer vision-based multiview stereo-image sensing

BackgroundPrecise anthropometric data are vital for ergonomic assessment and farm machinery design. Manual methods, although dependable, are labor-intensive and susceptible to error.ObjectiveThis study aimed to develop and validate a computer vision (CV) based non-contact system for anthropometric measurements, focusing on stature, vertical reach, trochanteric height, and chest circumference.MethodsAn Intel RealSense D435i stereo camera with OpenCV, mediapipe captured images from three angles (front, diagonal, side) at 2.5-3.5 m. Thirty-two participants (16 male, 16 female) were measured, with manual anthropometry as reference. Accuracy was assessed using mean absolute difference (MAD) and mean absolute percentage error (MAPE), while reliability was examined via intraclass correlation coefficient (ICC, p < 0.05).ResultsThe 3.0 m front-facing view yielded the most accurate measurements. CV-based anthropometry slightly underestimated stature for males (1596 vs. 1646 mm) and females (1456 vs. 1521 mm; MAD 53-65 mm; MAPE 3-4%), with excellent reliability (ICC > 0.90, α > 0.85). Vertical reach showed the largest bias (83-90 mm; MAPE 4-5%), yet reliability remained high (ICC 0.88-0.91). Trochanteric height had minimal discrepancies (29-36 mm; MAPE ≤ 4%) with good consistency (ICC 0.85-0.90). Chest circumference showed small bias (±10 mm; MAPE 3-4%) but lower reliability (ICC 0.75-0.80), likely due to respiration. Overall, CV measurements were reliable, non-invasive, and scalable.ConclusionsThe CV-based system offers a precise, scalable, and non-contact alternative to manual anthropometry, enabling reliable data collection for ergonomic evaluation and improved man-machine compatibility in agriculture.