Fig. 1. Vis-NIR spectra collection system

Fig. 2. The multi-scale CNN structure

Fig. 3. Vis-NIR spectra of pesticide residues on the Hami melon surface
(a): Raw spectra; (b): Average spectra

Fig. 4. GAF image of Vis-NIR spectra
(a1, a2, a3): No residues; (b1, b2, b3): Chlorothalonil residues; (c1, c2, c3): Imidacloprid residues;(1): Standardization; (2): GASF; (3): GADF

Fig. 5. The training results of the multi-scale CNN model
(a): GASF; (b): GADF

Fig. 6. The confusion matrixof the multi-scale CNN model
(a): GASF; (b): GADF