Figure 1

Mango samples with different maturity"

Figure 2

Mango image processing procedure"

Figure 3

Mango image processing results a—Original image of mango；b—Mango image after extracting yellow pigment；c—Binary image of mango；d—Binary plot of extracting yellow pigment."

Figure 4

Mango maturity modeling flowchart"

Table 1

Maturity index distribution of mango with different maturity level during storage period"

Figure 5

Box plot of mango firmness data Different lowercase letters indicate significant differences（P<0.05）. The same as Figure 6 to Figure 8."

Figure 6

Box plot of mango sugar content data"

Figure 7

Box plot of mango RGB color model components Ⅰ—Box plot of mango R component；Ⅱ—Box plot of mango G component；Ⅲ—Box plot of mango B component. R，G and B represent the R component，G component，and B component of the RGB color model，respectively."

Figure 8

Box plot of mango HSV color model components Ⅰ—Box plot of mango H component；Ⅱ—Box plot of mango S component. H，S represent the H component and S component of the HSV color model，respectively."

Table 2

Distribution of mango maturity over time"

Table 3

Index component values of unripe mango over time"

Figure 9

Changes in unripe mango maturity index over time"

Table 4

Prediction results of BP neural network optimized by genetic algorithm"

Figure 10

Comparison of BP neural network optimized by genetic algorithm test set results"

Table 5

Predicted results of BP neural network"

Figure 11

Comparison of BP neural network test set results"

Table 6

Comparison of predicted accuracy of the two algorithms"