Image analysis and calliper measurements correlation.

Size change correlation between image analysis (size index and spread) and calliper area measurements (length × diameter). Correlation for different disk approximation types for batches C and D are shown. The size index is calculated using morphological openings and then using the mean, median or the opening intensity at the position of the pattern spectrum maximum (APM). The Interquartile Range (IQR) is used as a variation measurement. Pellets in dry condition.