Crop image to random size and aspect ratio

Source: R/transforms-generics.R

Crop the given image to a random size and aspect ratio. The image can be a Magick Image or a Tensor, in which case it is expected to have [..., H, W] shape, where ... means an arbitrary number of leading dimensions

transform_random_resized_crop(
  img,
  size,
  scale = c(0.08, 1),
  ratio = c(3/4, 4/3),
  interpolation = 2
)

Arguments

img

A magick-image, array or torch_tensor.

size

(integer vector or integer): Desired output size. If size is an integer vector of length 2 like c(h, w), output size will be matched to this. If size is a bare integer, smaller edge of the image will be matched to this number, i.e., if height > width, then image will be rescaled to (size * height / width, size).

scale

(numeric vector of length 2): Range of size of the origin size cropped.

ratio

(numeric vector of length 2): Range of aspect ratio of the origin aspect ratio cropped. ratio cropped.

interpolation

(integer, optional): Desired interpolation. An integer 0 = nearest, 2 = bilinear, and 3 = bicubic or a name from magick::filter_types().

Details

A crop of random size (default: of 0.08 to 1.0) of the original size and a random aspect ratio (default: of 3/4 to 4/3) of the original aspect ratio is made. This crop is finally resized to given size. This is popularly used to train the Inception networks.