t transforms (translate, shear, rotate and etc) the input image and mixes it with the original image
Image transformation involves series of randomly selected augmentation operations applied with three parallel augmentation chains.
Each chain has a composition of operations that could involve applying, for example, translation on input image followed by shear and so on
The output of these three chains is three images mixed to form a new image.
This new image is later mixed with the original image to generate the final augmented output image,
while we considered mixing by alpha compositing, we chose to use elementwise convex combinations for simplicity. The k-dimensional vector of convex coefficients is randomly sampled from a Dirichlet(α, … , α) distribution.
Once these images are mixed, we use a “skip connection” to combine the result of the augmentation chain and the original image through a second random convex combination sampled from a Beta(α, α) distribution. The final image incorporates several sources of randomness from the choice of operations, the severity of these operations, the lengths of the augmentation chains, and the mixing weights