Wow, this is great! Maybe i'll shelf my efforts a bit , if your online photo editor is this good... I did Google around and find some of these GraphCut-esque refinement techniques, but have yet to find an easily usable one that gave you a good crop with just an outline or tap (or both) - kudos for making one!
As to the lack of precision of ObjectCropBot, I think a lot of that is due to it running based on DeepMask and not SharpMask; Facebook's insight to run the final low-res features back through increasingly less downsized images with sort of skip connections is a good one, and I'd bet the resolution of the results would be a lot better if I just hacked it to use that instead of DeepMask (I think the thing I linked just uses that, pretty much).
As to the lack of precision of ObjectCropBot, I think a lot of that is due to it running based on DeepMask and not SharpMask; Facebook's insight to run the final low-res features back through increasingly less downsized images with sort of skip connections is a good one, and I'd bet the resolution of the results would be a lot better if I just hacked it to use that instead of DeepMask (I think the thing I linked just uses that, pretty much).