Table 5.

Differences in data augmentation

RK	Mirroring	Rotation	Color	Other
Sub-challenge 1: DR grading
1	N	N	N	N
2	H/V/HV	R: −30, +30	N	N
3	H/V	R: −20, +20	ID/N	R/ET/
	/HV			GT/AT
Sub-challenge 2: image quality assessment
1	N	N	CM/RC/MU	N
2	N	N	N	N
3	N	N	N	N
Sub-challenge 3: DR grading based on UWF fundus
1	H/V	R: −20, +20	ID/N	R/ET/
	/HV			GT/AT
2	N	N	N	N
3	N	N	N	RCC

H, horizontal flip; V, vertical flip; HV, horizontal and vertical flip; R, min degree, max degree:rotation angle; ID, image disturbance; N, noise; R, resize; ET, elastic transformation; GT, grid transformation; AT, affine transformation; RCC, random center cut; CM,³⁶ RC,³⁷ and MU,³⁸ preprocessing method in reference; RK, rank.