The type Rotate defines a generic anticlockwise rotation operation around the center of the image. It is also possible to pass some abstract vector to the constructor, in which case Augmentor will randomly sample one of its elements every time the operation is applied.

In [1]:

using Augmentor
using ImageShow, ImageCore
using Random
Random.seed!(0)

img_in = testpattern(RGB, ratio=0.5)
mosaicview(
    img_in,

    # deterministic rotation
    augment(img_in, Rotate(45)),

    # random rotation
    augment(img_in, Rotate(-45:45));
    fillvalue=colorant"white", nrow=1, npad=10
)

Out[1]:

Note that the output image size will be changed after rotation, CropNative can be particalually useful to preserve the image size.

In [2]:

mosaicview(
    augment(img_in, Rotate(45)),
    augment(img_in, Rotate(45) |> CropNative(axes(img_in)));
    nrow=1, npad=10
)

Out[2]:

Rotation by some special degree (e.g.,90, 180 and 270) can be handled more efficiently without interpolation. Compared to Rotate(90), it is recommended to use Rotate90 when possible. Rotate180 and Rotate270 are available, too.

References¶

This notebook was generated using Literate.jl.