How to add an image augmentation layer?

Hi, I am using MATLAB for deep learning. And was wondering how to add an image augmentation layer after the imageInputLayer. I have read that I can use "Create Custom Layer with Learnable Parameters". But I am not sure how to do that. Anyone already tried it?

All I need is to be able to manipulate my input batches right before they are used for training. Specifically, I want to train the VGG-19 from scratch. And there every image is supposed to be rescaled randomly, cropped randomly, and reflected randomly at every epoch.

I found that

imageDataAugmenter

can do the trick for re-scaling the images for example. But the scaling the DataAugmenter applies messes up the aspect ratio of the images because there is an X-scale and Y-scale.

Any idea?

Thank you in advance!