Table 1.

Action definition.

ai	Actions	Examples	Description
0	Original image		The resultant image is the same as the original one.
1	Vertical flip		The resultant image mirrors the original one along the horizontal center line.
2	Horizontal flip		The resultant image mirrors the original one along the vertical center line.
3	Vertical and horizontal flip		The original image is flipped vertically and horizontally to produce the resultant image.
4	Clockwise rotation		The original image is rotated 30° clockwise around the center point to produce the resultant image.
5	Affine transformation		The original image is transformed with the matrix [[1, 0.2, 0], [0, 1, 0]] to produce the resultant image.
6	Crop		The first 25 rows and 25 columns of pixels of the original image are trimmed and then the image is resized to 512 × 512 pixels to produce the resultant image.
7	Noise-adding		Some random white Gaussian noise is added to the original image to produce the resultant image.