Table 4.

Comparison of the denoising effect of different filtering techniques.

Filter type/kernel size	Grading	Precision	Recall	F1-score	Accuracy
Mean filtering/3	I	0.87	0.952	0.91	0.865
	II	0.872	0.81	0.84
	III	0.854	0.833	0.843
Mean filtering/5	I	0.868	0.786	0.825	0.810
	II	0.775	0.738	0.756
	III	0.792	0.905	0.844
Mean filtering/7	I	1.00	0.810	0.895	0.833
	II	0.816	0.738	0.775
	III	0.741	0.952	0.833
Median filtering/3	I	0.804	0.881	0.841	0.810
	II	0.767	0.786	0.776
	III	0.865	0.762	0.810
Median filtering/5	I	0.860	0.881	0.871	0.841
	II	0.795	0.833	0.814
	III	0.872	0.810	0.840
Median filtering/7	I	0.826	0.905	0.864	0.817
	II	0.861	0.738	0.795
	III	0.773	0.810	0.791
Bilateral filtering/3	I	0.860	0.881	0.871	0.825
	II	0.848	0.667	0.747
	III	0.780	0.929	0.848
Bilateral Filtering / 5	I	0.854	0.833	0.843	0.817
	II	0.729	0.833	0.778
	III	0.892	0.786	0.835
Gaussian filtering/3	I	0.917	0.786	0.846	0.810
	II	0.723	0.810	0.764
	III	0.814	0.833	0.824
Gaussian filtering/5	I	0.902	0.881	0.892	0.873
	II	0.850	0.810	0.829
	III	0.867	0.929	0.897
Gaussian filtering/7	I	0.860	0.881	0.871	0.857
	II	0.833	0.833	0.833
	III	0.878	0.857	0.867