How to crop images with a fixed aspect ratio

After a period of time, I want to re-evaluate MATLAB for image processing. I saw augmentedImageDatastore used to process image data in batches. I regret to find that MATLAB still cannot perform equal-scale cropping of images and cannot implement it manually. I don't think this is a complicated features.Why has it not been implemented yet?

Answer 1

[Walter Roberson]

Use a transform data store.

https://www.mathworks.com/help/matlab/ref/matlab.io.datastore.transform.html

Notice that transform() is specifically supported for that class; https://www.mathworks.com/help/deeplearning/ref/augmentedimagedatastore.html?searchHighlight=augmented%20data%20store&s_tid=srchtitle#d123e10506

[Shino Asada]

I used transform to achieve proportional scaling, but I encountered a problem when using it with augmentedImageDatastore. Transform should be used before it (because it needs to specify outputSize), but it does not support TransformedDatasore as input. How to solve it?