I see you have an option to crop the image... but what about offsetting the crop? I've looked at a few of these services and no one seems to give that option. I can process it myself but it would be nice to do it in one api call. For example set viewport to 1200 x 1900, crop to 300 x 400 at 500px from the top and 300px from the left. Or some coordinates from top and center perhaps...