Simultaneous surface area measurement for multiple objects by geodesic active contour

A novel scheme to the area measurement of multiple objects is proposed. This scheme is suitable for the simultaneous and exact measurement of multiple objects’ surface areas with different shapes. A geodesic active contour is applied and this scheme consists of three steps. Firstly, the active contour converges to the object's contour edge from an initial position via the iteration of level set functional ϕ. Secondly, for the convergent active contour, the sub-pixel area measurement and centroid measurement are applied to compute every object's area and centroid simultaneously. Finally, a centroid-self-calibration technology is applied, which measures the pixel's size equivalence with the computed centroid and a dual-frequency laser to measure every object's true surface area. Experiments indicate that this scheme's measurement repetition error can decrease to ±0.4% and that its single measurement error can decrease to ±0.2%. Compared to conventional area measurement schemes, this scheme is highly efficient (i.e., simultaneous measurement of multiple objects’ areas) and highly accurate.