I’m pretty sure the answer is no. Even full HTML won’t crop an image on the fly. You may be able to do it with CSS or JavaScript but that’s not an option in the journal.
This may be too tedious for your purposes but the process I’ve used for a small number of 3rd party images in journal posts is as follows:
– Download the image locally,
– Crop it as I need it,
– Upload the modified version to my Flickr account where it is given full original credit,
– Link to that Flickr image in the journal (using the “Embed” function from Flickr).
As long as the original image is CC0, out of copyright (old published works), or similar availability (or used with permission), I haven’t had any issues with this circuitous route.