Fatty areas in cured hams measured by computer image analysis. 2. Repeatability

This study aimed at estimating repeatability and reproducibility of computer digital image analysis (CIA) measures of areas visible on the cross-section of dry cured hams. A total of 7,533 measures were obtained by 3 operators using 3 CIA procedures (automatic, semiautomatic and manual) and performing 3 measures per each image (279 hams). Measured areas were i) entire ham section area (EHA), ii) 'fat-eye' area (FEA, visible fatty area placed roughly in the middle of the cross-section), iii) 'lean' area (LHA). Correlations and variance components were estimated using all measures or only measures obtained after operators were trained again for spatial calibration. Correlations for measures obtained with different CIA procedures were very high and ranged from 0.95 to 1 (P0.001). Repeatability and reproducibility estimated from all measures ranged from 0.82 to 0.97 and from 0.75 to 0.97, respectively. Estimates of repeatability and reproducibility exhibited a 8 to 15% increase when only measures collected after a new training for spatial calibration were considered. In conclusion, assessment of visual appearance of cross-sectioned dry cured hams can be obtained through CIA using one operator and a single measurement under accurate spatial calibration