Fig. 7

A a/b values from Lab colour space of test tomatoes captured on a Nikon D60 against lycopene content determined via extraction and spectrophotometry in mg lycopene per kg wet mass tomato. The solid line indicates an exponential fit of the data used to predict lycopene content. B Predicted lycopene content determined from Lab colour space of test tomatoes captured on Nikon D60 against lycopene content determined via extraction and spectrophotometry in mg lycopene per kg wet mass tomato. The dashed line indicates the y = x line. The pink circles show the data used to train the model and the blue squares indicate validation data points. C The standardised residuals of the training dataset, pink circles, and validation dataset, blue squares of the model fit and descriptive statistics of the model, with d.f; F and p indicating the degrees of freedom, F value and p value for an ANOVA of the predicted against observed values of the model for the training and validation datasets. RMSE is the root mean square error of the model