There are 2 interviews in total, 1 research interview and 1 coding interview, the research interview is talking about your own research work, and asked some specific questions about it. The coding interview only asked 1 question about image segmentation.

Had 2 phone interviews after I submitted my application online. The calls were over 1 month, and asked some questions that tested the skills I mentioned on my resume. They interviewers were helpful when I got stuck, and gave me pointers to help my thinking. The questions were quite hard, but preparation and doing your research will definitely help. Make sure you know everything you've mentioned in your resume.