Hi Michael,
Thanks for your question.
If you need to resize, apply augmentedimagedatastore to your image datastore - it will be much faster than a custom readfcn, because it preserves prefetch under the hood. If you don’t need to resize, augment, or any other need for a custom readfcn, then vanilla imds is simplest.
Another option is to create a custom layer but you're right, it'll take some work.
HTH Shounak
